Review on Low-Temperature Electrolytes for Lithium-Ion and Lithium Metal Batteries

In the paper

“Using the same salt LiPF 6 , the AN-based electrolyte has an ionic conductivity more than twice the value of the EC-DMC-based electrolyte at RT [52].”

What the sources say

• Disputed

  Section 3.1 (page not indicated in our copy) reports room-temperature ionic conductivities of 20.5 mS cm⁻¹ for the acetonitrile-containing electrolyte and 11.33 mS cm⁻¹ for the EC–DMC control. Both used 1 M LiPF6, but 20.5 is about 1.81 times 11.33, not more than twice. (LLM, conf=0.90)

  Checked by a reasoning model — may be wrong.

  cites [52] Cho, Y.G., Kim, Y.S., Sung, D.G., et al.: Nitrile-assistant eutectic electrolytes for cryogenic operation of lithium ion batteries at fast charges and discharges. Energy Environ. Sci. 7, 1737–1743 (2014). https://doi.org/10.1039/C3EE43029D sourceExperimental — accuracy not yet measured

In the paper

“Furthermore, in addition to the sulfur-containing additives mentioned above, elemental sulfur and allyl disulfide were also reported to have the capability to reduce SEI impedance as well, which can effectively improve LT battery performance [116,117].”

What the sources say

• Disputed

  The Results and Discussion report better low-temperature performance with elemental sulfur, but attribute it to lower charge-transfer resistance, not lower SEI resistance. They state that SEI resistance was higher for the sulfur-added electrode. The cited paper studies elemental sulfur, not allyl disulfide. (LLM, conf=0.88)

  Checked by a reasoning model — may be wrong.

  cites [116] Jurng, S., Kim, H.S., Lee, J.G., et al.: Low-temperature characteristics and film-forming mechanism of elemental sulfur additive on graphite negative electrode. J. Electrochem. Soc. 163, A223–A228 (2015). https://doi.org/10.1149/2.0421602jes sourceExperimental — accuracy not yet measured
• Partly supported

  The Abstract reports improved low-temperature graphite performance with elemental sulfur, and Results and Discussion reports a comparable improvement with allyl disulfide. Neither passage establishes that these two additives reduce SEI impedance. The paper attributes its measured impedance benefit for allyl sulfide to lower charge-transfer resistance, a different quantity (Results and Discussion, Table I; page numbers unavailable). (LLM, conf=0.88)

  cites [117] Jurng, S., Park, S., Yoon, T., et al.: Low-temperature performance improvement of graphite electrode by allyl sulfide additive and its film-forming mechanism. J. Electrochem. Soc. 163, A1798–A1804 (2016). https://doi.org/10.1149/2.0051609jes sourceExperimental — accuracy not yet measured

In the paper

“Meanwhile, high oxidation stability of this electrolyte enabled stable graphite||graphite cycling with the upper voltage cutoff at 5.2 V for the storage of PF 6 -anion in graphite at the cathode side.”

What the sources say

• Partly supported

  The Accepted Manuscript reports high oxidative stability for the MP-based electrolyte containing 10% FEC. The Angewandte Chemie International Edition section reports stable graphite||graphite full-cell cycling and PF6− storage in graphite at approximately 4.6–5.2 V versus Li/Li+. It does not identify 5.2 V as the full cell’s upper voltage cutoff; that number describes the positive electrode’s potential versus Li/Li+. (LLM, conf=0.87)

  cites [43] Holoubek, J., Yin, Y.J., Li, M.Q., et al.: Exploiting mechanistic solvation kinetics for dual-graphite batteries with high power output at extremely low temperature. Angewandte Chemie Int. Ed. 58, 18892–18897 (2019). https://doi.org/10.1002/anie.201912167 sourceExperimental — accuracy not yet measured

In the paper

“However, it could not be used in graphite anode contained battery systems as the major/single solvent due to the solvent co-intercalation and exfoliation of the graphite anodes [30,31].”

What the sources say

• ?Could not verify

  Section 1.4 describes graphite-electrode tests using DMC and EC electrolytes, but does not address propylene carbonate. Searches for propylene carbonate, co-intercalation, and exfoliation found no passage supporting the claimed restriction or its cause. Page numbers were not available in the indexed passages. (LLM, conf=0.74)

  cites [30] Wang, L.N., Menakath, A., Han, F.D., et al.: Identifying the components of the solid-electrolyte interphase in Li-ion batteries. Nat. Chem. 11, 789–796 (2019). https://doi.org/10.1038/s41557-019-0304-z sourceExperimental — accuracy not yet measured
• ?Not checked — no full text of the sourcecites [31] Xing, L.D., Zheng, X.W., Schroeder, M., et al.: Deciphering the ethylene carbonate-propylene carbonate mystery in Li-ion batteries. Acc. Chem. Res. 51, 282–289 (2018). https://doi.org/10.1021/acs.accounts.7b00474 source

In the paper

“As a result, this graphite||graphite dual-ion battery (DIB) retained 93.1% and 84.4% of its RT capacity at -40 and -60 °C, respectively (Fig. 6b).”

What the sources say

• Supported

  The main text reports that the graphite||graphite DIB retained 93.1% and 84.4% of its room-temperature capacity at −40 °C and −60 °C, respectively. The Figure 3 caption identifies these as discharge measurements at a 1 C rate; the citing paper’s “Fig. 6b” is its own figure reference, not a conflicting result. (LLM, conf=0.95)

  cites [43] Holoubek, J., Yin, Y.J., Li, M.Q., et al.: Exploiting mechanistic solvation kinetics for dual-graphite batteries with high power output at extremely low temperature. Angewandte Chemie Int. Ed. 58, 18892–18897 (2019). https://doi.org/10.1002/anie.201912167 source

In the paper

“This means at high charge rates the speed of Li + transport in the electrolyte cannot catch up with the Li + entering the electrode, resulting in a steep Li + concentration profile at the interphase limiting the LIB performance [7,8].”

What the sources say

• Partly supported

  Split into 2 atoms — 0 confirmed, 2 partially supported, 0 disputed, 0 misattributed, 0 unverifiable. Expand the claim to see per-atom verdicts.

  cites [7] Fong, K.D., Self, J., Diederichsen, K.M., et al.: Ion transport and the true transference number in nonaqueous polyelectrolyte solutions for lithium ion batteries. ACS Cent. Sci. 5, 1250–1260 (2019). https://doi.org/10.1021/acscentsci.9b00406 sourceExperimental — accuracy not yet measured
• ?Not checked — no full text of the sourcecites [8] Piao, N., Gao, X.N., Yang, H.C., et al.: Challenges and development of lithium-ion batteries for low temperature environments. eTransportation 11, 100145 (2022). https://doi.org/10.1016/j.etran.2021.100145 source

In the paper

“The stable interphase formed by FEC combined with high bulk electrolyte conductivity contributed by MP enabled greatly improved performance, delivering over 60% RT capacity at -60 °C and 1 C rate (Fig. 6a).”

What the sources say

• Supported

  Split into 2 atoms — 2 confirmed, 0 partially supported, 0 disputed, 0 misattributed, 0 unverifiable. Expand the claim to see per-atom verdicts.

  cites [43] Holoubek, J., Yin, Y.J., Li, M.Q., et al.: Exploiting mechanistic solvation kinetics for dual-graphite batteries with high power output at extremely low temperature. Angewandte Chemie Int. Ed. 58, 18892–18897 (2019). https://doi.org/10.1002/anie.201912167 source

In the paper

“Moreover, the energy density and power density of LIBs at -40 °C can only retain a very small percentage of their values at RT, respectively [4].”

What the sources say

• Supported

  Page 1 compares Panasonic 18650 Li-ion cells at 25°C and -40°C: delivered energy density falls from about 100 to 5 Wh/l, and power density from about 800 to less than 10 W/l. The Charge/Discharge Characteristics section (p. 7) also reports that both delivered energy and power decrease with temperature and that performance at -40°C is very poor. (LLM, conf=0.93)

  cites [4] Nagasubramanian, G.: Electrical characteristics of 18 650 Li-ion cells at low temperatures. J. Appl. Electrochem. 31, 99–104 (2001). https://doi.org/10.1023/A:1004113825283 source

In the paper

“They suggested that the melting point of the mixed solvent is related to the composition, the melting point of each component, and the relative content.”

What the sources say

• Supported

  The opening discussion says that component melting points anchor the liquidus surface of a ternary mixture, while a quaternary solvent’s liquidus temperature varies with composition. The Liquidus Surface of Selected Ternary Carbonates section describes how adding different amounts of the other components changes that surface. The paper calls the mixture’s lower liquid-range boundary its liquidus temperature rather than its melting point. (LLM, conf=0.91)

  cites [18] Ding, M.S.: Liquid-solid phase diagrams of ternary and quaternary organic carbonates. J. Electrochem. Soc. 151, A731 (2004). https://doi.org/10.1149/1.1690782 source

In the paper

“Chen's group [44] further demonstrated stable charge and discharge performance of NMC111-graphite pouch cell in MP-based electrolyte at the subzero temperatures of -20 and -40 °C.”

What the sources say

• Supported

  The paper’s summary states that NMC111||graphite pouch cells using an MP-based electrolyte showed improved capacity retention and Coulombic efficiency at both -20 and -40 °C. The cycling-results passages report stable charge and discharge performance at -20 °C and stable capacity retention and Coulombic efficiency at -40 °C. Page numbers are not provided in our copy. (LLM, conf=0.94)

  cites [44] Cho, Y.G., Li, M.Q., Holoubek, J., et al.: Enabling the low-temperature cycling of NMC||graphite pouch cells with an ester-based electrolyte. ACS Energy Lett. 6, 2016–2023 (2021). https://doi.org/10.1021/acsenergylett.1c00484 source

In the paper

“The electrolytes using EMC as the single solvent can even work on graphite anodes without EC when LiAsF 6 salt was used [24].”

What the sources say

• Supported

  The Results and Discussion report that graphite electrodes cycle well in single-solvent EMC and that their performance in pure EMC with 1 M LiAsF6 is as good as in EMC–EC mixtures. The Fig. 1 caption also identifies the EMC–LiAsF6 graphite-cycling experiment. This supports the claim that the electrolyte works without EC; it does not imply that EC offers no improvement. (LLM, conf=0.94)

  cites [24] Ein-Eli, Y., Thomas, S.R., Koch, V., et al.: Ethylmethylcarbonate, a promising solvent for Li-ion rechargeable batteries. J. Electrochem. Soc. 143, L273–L277 (1996). https://doi.org/10.1149/1.1837293 source

In the paper

“MPC electrolyte could enable reversible lithium intercalation into the graphite anode.”

What the sources say

• Supported

  The Results and Discussion (Fig. 1, p. L181) report intercalation–deintercalation cycles of a graphite electrode in MPC/1 M LiPF6. The authors explicitly conclude that graphite electrodes cycle reversibly in the single-solvent MPC electrolyte. (LLM, conf=0.94)

  cites [28] Ein-Eli, Y., McDevitt, S.F., Aurbach, D., et al.: Methyl propyl carbonate: a promising single solvent for Li-ion battery electrolytes. J. Electrochem. Soc. 144, L180–L184 (1997). https://doi.org/10.1149/1.1837792 source

In the paper

“They showed that EMC can form much stabler SEI on graphite than DMC.”

What the sources say

• Supported

  The Introduction (page unavailable) says EMC electrolytes form highly efficient passivating layers on graphite that confer high cycling stability, and describes EMC as superior to other alkyl carbonates. The Results and Discussion table (page unavailable) reports poor graphite performance with DMC versus substantially better performance with EMC, supporting the paraphrased comparison. (LLM, conf=0.85)

  cites [23] Ein-Eli, Y., McDevitt, S.F., Laura, R.: The superiority of asymmetric alkyl methyl carbonates. J. Electrochem. Soc. 145, L1–L3 (1998). https://doi.org/10.1149/1.1838196 source

In the paper

“Meanwhile, the Li + (DEE) 1.8 complexes possessed a much lower binding energy of -280 kJ mol -1 than that of Li + (DME) 2.3 (-414 kJ mol -1 ) formed in 1 M LiFSI in DOL-DME electrolytes shown in Fig. 8a.”

What the sources say

• Supported

  The Electrolyte Solvation Structure and Performance Impact section reports calculated binding energies of −280 kJ mol−1 for Li+(DEE)1.8 and −414 kJ mol−1 for Li+(DME)2.3. It identifies the DME-coordinated system as 1 M LiFSI in DOL/DME and the DEE-coordinated system as 1 M LiFSI in DEE; the energies are presented as qualitative indicators of desolvation barriers. (LLM, conf=0.93)

  cites [57] Holoubek, J., Liu, H.D., Wu, Z.H., et al.: Tailoring electrolyte solvation for Li metal batteries cycled at ultra-low temperature. Nat. Energy (2021). https://doi.org/10.1038/s41560-021-00783-z source

In the paper

“Different from typical solvent-separated ion pair (SSIP) solvation structure, DEE electrolytes presented characteristic CIPs with 1.8 DEE oxygens and 2.0 FSI -oxygens per Li + .”

What the sources say

• Supported

  The “Electrolyte Solvation Structure and Performance Impact” section reports that MD simulations found a characteristic contact-ion-pair structure in 1 M LiFSI DEE, with average coordination numbers of 1.8 DEE oxygens and 2.0 FSI− oxygens per Li+. It contrasts this with the solvent-separated ion-pair structure of 1 M LiFSI in DOL/DME. (LLM, conf=0.95)

  cites [57] Holoubek, J., Liu, H.D., Wu, Z.H., et al.: Tailoring electrolyte solvation for Li metal batteries cycled at ultra-low temperature. Nat. Energy (2021). https://doi.org/10.1038/s41560-021-00783-z source

In the paper

“When the electrolytes containing high concentration of these salts are used in Li metal anode cells, they can form salt anion-derived SEI with a LiF-rich component which is beneficial for anode protection and electrochemical performance [104].”

What the sources say

• Partly supported

  The Results section (“Formation of a stable SEI layer”; page not available) reports that a protective SEI forms with 4 M LiFSI-DME and that increasing fluoride content during cycling may result from anion degradation. It does not identify the SEI as LiF-rich or establish the same SEI mechanism for highly concentrated LiTFSI in Li-metal cells; its discussion of concentrated LiTFSI concerns Li|graphite cells. (LLM, conf=0.87)

  cites [104] Qian, J.F., Henderson, W.A., Xu, W., et al.: High rate and stable cycling of lithium metal anode. Nat. Commun. 6, 6362 (2015). https://doi.org/10.1038/ncomms7362 sourceExperimental — accuracy not yet measured

In the paper

“Recently, Cho et al. [52] introduced nitriles with varying length of alkyl chains and low melting points into EC or EC-DMC-based electrolyte to lower the freezing point of solvent mixtures.”

What the sources say

• Supported

  Section 3.1 describes nitriles with different alkyl-chain lengths and low freezing points as co-solvents for EC/DMC mixtures. Section 3.4 examines their eutectic behavior, and the paper states that freezing-point depression results from combining EC/DMC with propionitrile. Page numbers are not available in our copy. (LLM, conf=0.90)

  cites [52] Cho, Y.G., Kim, Y.S., Sung, D.G., et al.: Nitrile-assistant eutectic electrolytes for cryogenic operation of lithium ion batteries at fast charges and discharges. Energy Environ. Sci. 7, 1737–1743 (2014). https://doi.org/10.1039/C3EE43029D source

In the paper

“Moreover, in all electrolyte systems studied by Cho, 2% FEC was used as SEI additive to relieve the graphite incompatibility issue of nitriles.”

What the sources say

• Partly supported

  Section 2.1 (page unavailable) states that 2 wt% FEC was used as an SEI-forming agent for the cell tests, supporting the amount and additive role. It does not say FEC was used in every electrolyte measurement or that its purpose was specifically to relieve nitrile–graphite incompatibility. (LLM, conf=0.88)

  cites [52] Cho, Y.G., Kim, Y.S., Sung, D.G., et al.: Nitrile-assistant eutectic electrolytes for cryogenic operation of lithium ion batteries at fast charges and discharges. Energy Environ. Sci. 7, 1737–1743 (2014). https://doi.org/10.1039/C3EE43029D sourceExperimental — accuracy not yet measured

In the paper

“The highly improved bulk ion transport properties effectively increased the discharge/charge capacity of graphite||NCA full cells at LT (-20 °C) (Fig. 7b).”

What the sources say

• Supported

  Section 3.1 reports substantially higher ionic conductivity for the nitrile-containing electrolytes at −20 °C. Section 3.2 reports significantly higher discharge and charge capacities for NCA/graphite full cells using those electrolytes than for controls at that temperature. The paper also notes that conductivity alone does not fully explain the performance improvement. (LLM, conf=0.90)

  cites [52] Cho, Y.G., Kim, Y.S., Sung, D.G., et al.: Nitrile-assistant eutectic electrolytes for cryogenic operation of lithium ion batteries at fast charges and discharges. Energy Environ. Sci. 7, 1737–1743 (2014). https://doi.org/10.1039/C3EE43029D source

In the paper

“In contrast, the Li/SPAN cell using 1 M LiFSI in DOL/DME failed immediately at -60 °C.”

What the sources say

• Partly supported

  The Full Cell Behavior section (Fig. 6g; page not provided) reports that the Li||SPAN cell using 1 M LiFSI in DOL/DME had no viable capacity output after two cycles at −60 °C. This supports failure at that temperature, but not the claim that it failed immediately. (LLM, conf=0.88)

  cites [57] Holoubek, J., Liu, H.D., Wu, Z.H., et al.: Tailoring electrolyte solvation for Li metal batteries cycled at ultra-low temperature. Nat. Energy (2021). https://doi.org/10.1038/s41560-021-00783-z sourceExperimental — accuracy not yet measured

In the paper

“An effective measure to address this issue is to introduce diluents (i.e., hydrofluoroethers) to form the LHCE which has the advantages of both good SEI formation capability and low viscosity [62,[105][106][107].”

What the sources say

• ?Not checked — no full text of the sourcecites [62] Fan, X.L., Ji, X., Chen, L., et al.: All-temperature batteries enabled by fluorinated electrolytes with non-polar solvents. Nat. Energy 4, 882–890 (2019). https://doi.org/10.1038/s41560-019-0474-3 source
• Supported

  The Results and Discussion section reports that adding the fluorinated ether BTFE preserves the concentrated electrolyte’s solvation structure while reducing viscosity from 150 to 2.9 mPa s. It also attributes the electrolyte’s high efficiency and rate capability to a robust, LiF-rich SEI formed in the LHCE. Page numbers are unavailable in our copy. (LLM, conf=0.91)

  cites [105] Chen, S.R., Zheng, J.M., Yu, L., et al.: High-efficiency lithium metal batteries with fire-retardant electrolytes. Joule 2, 1548–1558 (2018). https://doi.org/10.1016/j.joule.2018.05.002 source
• ?Not checked — no full text of the sourcecites [106] Zheng, Y., Soto, F.A., Ponce, V., et al.: Localized high concentration electrolyte behavior near a lithium-metal anode surface. J. Mater. Chem. A 7, 25047–25055 (2019). https://doi.org/10.1039/C9TA08935G source

In the paper

“However, pouch cells using electrolytes with shorter alkyl chain nitrile (i.e., AN) with a higher ionic conductivity delivered less discharge capacity at the same condition compared with propionitrile (PN), which has the best retention at -20 °C for RT capacity.”

What the sources say

• Partly supported

  Split into 2 atoms — 0 confirmed, 2 partially supported, 0 disputed, 0 misattributed, 0 unverifiable. Expand the claim to see per-atom verdicts.

  cites [52] Cho, Y.G., Kim, Y.S., Sung, D.G., et al.: Nitrile-assistant eutectic electrolytes for cryogenic operation of lithium ion batteries at fast charges and discharges. Energy Environ. Sci. 7, 1737–1743 (2014). https://doi.org/10.1039/C3EE43029D sourceExperimental — accuracy not yet measured

In the paper

“The electrolyte ionic conductivity was greatly improved after introducing nitriles (Fig. 7a).”

What the sources say

• Supported

  Section 3.1 (Transport properties of electrolytes) states that adding nitriles to the EC/DMC electrolyte significantly improved ionic conductivity. It reports increases at both room temperature and −20 °C for all three nitrile-containing formulations compared with the control. (LLM, conf=0.94)

  cites [52] Cho, Y.G., Kim, Y.S., Sung, D.G., et al.: Nitrile-assistant eutectic electrolytes for cryogenic operation of lithium ion batteries at fast charges and discharges. Energy Environ. Sci. 7, 1737–1743 (2014). https://doi.org/10.1039/C3EE43029D source

In the paper

“It was reported that the addition of ionic additive LiFSI can suppress the Li plating compared to the baseline cell.”

What the sources say

• Supported

  The results section reports Li metal particles on the baseline cell’s graphite anode, while the anode cycled with LiFSI had a plating-free surface. The Conclusions likewise state that LiFSI inhibits Li metal plating under the study’s −20 °C conditions. (LLM, conf=0.94)

  cites [139] Pham, H.Q., Chung, G.J., Han, J., et al.: Interface stabilization via lithium bis(fluorosulfonyl)imide additive as a key for promoted performance of graphite‖LiCoO2 pouch cell under − 20 °C. J. Chem. Phys. 152, 094709 (2020). https://doi.org/10.1063/1.5144280 source

In the paper

“Strangely, the signature of Li fluoride (LiF) lattice was not detected, even though LiF is considered to be a primary reason for performance enhancement [162].”

What the sources say

• Supported

  The passage describing the FEC-containing electrolyte’s SEI (section labeled Abstract, Fig. 4H) explicitly says that the LiF lattice could not be detected. It also states that LiF is considered a primary reason for performance enhancement. (LLM, conf=0.95)

  cites [165] Li, Y.Z., Li, Y.B., Pei, A., et al.: Atomic structure of sensitive battery materials and interfaces revealed by cryo-electron microscopy. Science 358, 506–510 (2017). https://doi.org/10.1126/science.aam6014 source

In the paper

“In the former [164], cryo-EM was reported to outperform other techniques used for characterizing the sensitive chemical composition and spatial distribution of the SEI, as well as the morphology at nanoscale.”

What the sources say

• Supported

  The discussion on p. 2 explicitly says cryo-EM outperforms other techniques for characterizing electrochemically deposited lithium, including the SEI’s chemical composition and spatial distribution at the nanoscale. This supports the citing sentence in its lithium-metal context. (LLM, conf=0.95)

  cites [164] Wang, X.F., Zhang, M.H., Alvarado, J., et al.: New insights on the structure of electrochemically deposited lithium metal and its solid electrolyte interphases via cryogenic TEM. Nano Lett. 17, 7606–7612 (2017). https://doi.org/10.1021/acs.nanolett.7b03606 source

In the paper

“In contrast, only ~ 175 mAh g -1 was obtained at the same condition for a cell using the electrolyte without FEC (Fig. 14a) [125].”

What the sources say

• Partly supported

  The Results and Discussion section reports that a cell without FEC had a lower first-cycle discharge capacity at −20 °C than a cell with 2% FEC. It does not give an absolute capacity of approximately 175 mAh g⁻¹, so the cited text supports the comparison but not the claimed number. (LLM, conf=0.83)

  cites [125] Liu, B.X., Li, B., Guan, S.Y.: Effect of fluoroethylene carbonate additive on low temperature performance of Li-ion batteries. Electrochem. Solid-State Lett. 15, A77 (2012). https://doi.org/10.1149/2.027206esl sourceExperimental — accuracy not yet measured

In the paper

“This difference was attributed to the decreased charge transfer and the SEI impedance after forming LiF-rich SEIs with FEC.”

What the sources say

• Supported

  The Abstract attributes the improved low-temperature capacity with FEC to reduced charge-transfer resistance and lower SEI-film resistance associated with a LiF-richer film. The Results and Discussion reports lower SEI resistance and evidence of reduced charge-transfer resistance; the Conclusions links improved performance to the LiF-richer SEI. (LLM, conf=0.93)

  cites [125] Liu, B.X., Li, B., Guan, S.Y.: Effect of fluoroethylene carbonate additive on low temperature performance of Li-ion batteries. Electrochem. Solid-State Lett. 15, A77 (2012). https://doi.org/10.1149/2.027206esl source

In the paper

“By using conventional carbonate electrolyte with FEC as the additive, it was reported that a capacity of ~ 320 mAh g -1 was delivered when a Li/graphite cell was discharged at -20 °C (a 1/15C rate).”

What the sources say

• Partly supported

  The Experimental section (page unavailable) describes Li/graphite cells using a carbonate electrolyte with FEC and discharge at −20 °C at 1/15C. Results and Discussion (page unavailable) reports increased discharge capacity with FEC, but our copy gives no value of approximately 320 mAh g⁻¹; a search for 320 did not find it. (LLM, conf=0.86)

  cites [125] Liu, B.X., Li, B., Guan, S.Y.: Effect of fluoroethylene carbonate additive on low temperature performance of Li-ion batteries. Electrochem. Solid-State Lett. 15, A77 (2012). https://doi.org/10.1149/2.027206esl sourceExperimental — accuracy not yet measured

In the paper

“Their results show that lithium ethylene mono-carbonate (LEMC), instead of lithium ethylene di-carbonate (LEDC), becomes the major organic components in the SEI on graphite anodes in LiPF 6 -EC/DMC electrolytes, after prolonged cycling.”

What the sources say

• Partly supported

  Section 1.5 describes analyzing the SEI on graphite after three cycles in LiPF6/EC/DMC, using LEMC and LEDC as reference materials. Supplementary Figure 26 reports that LEMC was more persistent than LEDC in separate reaction tests, but those tests do not establish which compound dominates the graphite SEI. The available passages do not support the claim that LEMC becomes its major organic component after prolonged cycling. (LLM, conf=0.78)

  cites [30] Wang, L.N., Menakath, A., Han, F.D., et al.: Identifying the components of the solid-electrolyte interphase in Li-ion batteries. Nat. Chem. 11, 789–796 (2019). https://doi.org/10.1038/s41557-019-0304-z sourceExperimental — accuracy not yet measured

In the paper

“The amorphous matrix is likely the organic polymer formed by carbonate electrolyte decomposition.”

What the sources say

• Supported

  Passage [1] states that, in the SEI formed in a carbonate-based EC-DEC electrolyte, crystalline domains are dispersed through an amorphous matrix and that the matrix is likely an organic polymer formed by carbonate electrolyte decomposition. The citing sentence retains the paper’s uncertainty qualifier. (LLM, conf=0.95)

  cites [165] Li, Y.Z., Li, Y.B., Pei, A., et al.: Atomic structure of sensitive battery materials and interfaces revealed by cryo-electron microscopy. Science 358, 506–510 (2017). https://doi.org/10.1126/science.aam6014 source

In the paper

“Some boron-based salts described in Sect.3, such as LiBOB, LiDFOB and similar derivatives, were also used as electrolyte additives due to their good SEI film-forming properties [136, 137].”

What the sources say

• Partly supported

  The Introduction describes LiBOB as an electrolyte additive among formulations containing SEI-promoting additives. It does not identify LiDFOB or similar boron-based derivatives as additives. The Results and Discussion attribute the LiBOB formulation’s improved performance to a possible cathode electrolyte interface (CEI) effect, rather than demonstrating SEI film formation. (LLM, conf=0.88)

  cites [136] Smart, M.C., Hwang, C., Krause, F.C., et al.: Wide operating temperature range electrolytes for high voltage and high specific energy Li-ion cells. ECS Trans. 50, 355–364 (2013). https://doi.org/10.1149/05026.0355ecst sourceExperimental — accuracy not yet measured
• ?Not checked — no full text of the sourcecites [137] Cappetto, A., Cao, W.J., Luo, J.F., et al.: Performance of wide temperature range electrolytes for Li-Ion capacitor pouch cells. J. Power Sources 359, 205–214 (2017). https://doi.org/10.1016/j.jpowsour.2017.05.071 source

In the paper

“These crystalline grains are the inorganic components of the SEI, identified to be Li oxide and Li carbonate by matching their lattice spacings.”

What the sources say

• Supported

  The passage describing the SEI formed in standard EC-DEC electrolyte states that its crystalline grains are inorganic components identified as Li oxide and Li carbonate by matching lattice spacings (Fig. 4G). The Fig. 4E caption independently describes the same lattice-spacing matches. (LLM, conf=0.95)

  cites [165] Li, Y.Z., Li, Y.B., Pei, A., et al.: Atomic structure of sensitive battery materials and interfaces revealed by cryo-electron microscopy. Science 358, 506–510 (2017). https://doi.org/10.1126/science.aam6014 source

In the paper

“For the first time, cryo-TEM elucidates the nanostructure of the electrochemically deposited Li (EDLi) and its surface SEI film.”

What the sources say

• Supported

  The paper states explicitly on p. 2 that, for the first time, cryo-TEM elucidates the nanostructure of electrochemically deposited Li and its surface film. Its discussion on p. 3 identifies that film as the SEI and describes its observed structure. (LLM, conf=0.95)

  cites [164] Wang, X.F., Zhang, M.H., Alvarado, J., et al.: New insights on the structure of electrochemically deposited lithium metal and its solid electrolyte interphases via cryogenic TEM. Nano Lett. 17, 7606–7612 (2017). https://doi.org/10.1021/acs.nanolett.7b03606 source

In the paper

“At -40 °C, the Li-LFP cell showed 90% capacity retention after 100 cycles at the cathode-limited areal capacity (5 mAh cm -2 ).”

What the sources say

• ?Could not verify

  The Experimental Section (page unavailable) describes graphite‖LiCoO₂ pouch cells cycled at −20 °C for 50 cycles, not Li–LFP cells. A search for Li–LFP, −40 °C, 100 cycles, and 5 mAh cm⁻² found no passage reporting the claimed result; the different experiment does not establish that the claimed result is false. (LLM, conf=0.76)

  cites [139] Pham, H.Q., Chung, G.J., Han, J., et al.: Interface stabilization via lithium bis(fluorosulfonyl)imide additive as a key for promoted performance of graphite‖LiCoO2 pouch cell under − 20 °C. J. Chem. Phys. 152, 094709 (2020). https://doi.org/10.1063/1.5144280 sourceExperimental — accuracy not yet measured

In the paper

“In the latter [165], the SEI was revealed to contain small crystalline domains (diameter ~ 3 nm) dispersed randomly throughout an amorphous matrix that coats the Li metal.”

What the sources say

• Supported

  The passage discussing Fig. 4E (labeled Abstract in our copy) states the claim almost verbatim. It describes the SEI formed on Li metal in the standard EC–DEC electrolyte. (LLM, conf=0.95)

  cites [165] Li, Y.Z., Li, Y.B., Pei, A., et al.: Atomic structure of sensitive battery materials and interfaces revealed by cryo-electron microscopy. Science 358, 506–510 (2017). https://doi.org/10.1126/science.aam6014 source

In the paper

“Unfortunately, the benefit of using FEC decreased rapidly during cycling and became insignificant after 25 cycles at -20”

What the sources say

• Supported

  The Results and Discussion (page not provided) say FEC had limited effects on specific capacity after 25 cycles at −20 °C and that the cells with and without FEC then had comparable capacity. The same section describes a rapid rise in SEI film resistance during cycling, supporting the reported decline in benefit. (LLM, conf=0.93)

  cites [125] Liu, B.X., Li, B., Guan, S.Y.: Effect of fluoroethylene carbonate additive on low temperature performance of Li-ion batteries. Electrochem. Solid-State Lett. 15, A77 (2012). https://doi.org/10.1149/2.027206esl source

In the paper

“The SEI formed in this standard electrolyte resembles the mosaic structure predicted by Peled et al. [166], who described the SEI as a heterogeneous distribution of inorganic and organic components.”

What the sources say

• Supported

  The passage labeled Abstract directly states that the SEI formed in the standard electrolyte resembles the mosaic structure predicted by Peled et al. It also describes that structure as a heterogeneous distribution of inorganic and organic components. (LLM, conf=0.95)

  cites [165] Li, Y.Z., Li, Y.B., Pei, A., et al.: Atomic structure of sensitive battery materials and interfaces revealed by cryo-electron microscopy. Science 358, 506–510 (2017). https://doi.org/10.1126/science.aam6014 source
• Supported

  The Results and Discussion describes SEI materials forming simultaneously and precipitating as a “mosaic of microphases.” Its examples include inorganic compounds and organic materials, supporting the attributed description of a heterogeneous structure. Whether the citing authors’ SEI resembles that model is their own comparison. (LLM, conf=0.92)

  cites [166] Peled, E., Golodnitsky, D., Ardel, G.: Advanced model for solid electrolyte interphase electrodes in liquid and polymer electrolytes. J. Electrochem. Soc. 144, L208–L210 (1997). https://doi.org/10.1149/1.1837858 source

In the paper

“They also observed a completely different SEI structure when it was formed in a carbonate-based electrolyte with 10% FEC.”

What the sources say

• Supported

  The passage discussing Fig. 4H explicitly reports a completely different SEI structure in a carbonate-based electrolyte with 10 volume % FEC. It contrasts the more ordered, apparently multilayer structure with the randomly distributed components observed in the standard electrolyte. The supplied copy labels this passage as Abstract; no page number is given. (LLM, conf=0.95)

  cites [165] Li, Y.Z., Li, Y.B., Pei, A., et al.: Atomic structure of sensitive battery materials and interfaces revealed by cryo-electron microscopy. Science 358, 506–510 (2017). https://doi.org/10.1126/science.aam6014 source

In the paper

“Instead of a random distribution of organic and inorganic components, the SEI formed in the presence of FEC is more ordered and appears to have a multilayer structure, consistent with the multilayer system proposed by Aurbach et al. [167].”

What the sources say

• Supported

  The passage discussing Fig. 4H states that, compared with the random distribution in the standard electrolyte, the SEI formed with FEC is more ordered and appears multilayered. It explicitly says this is consistent with the multilayer system proposed by Aurbach et al. The supplied copy labels this passage “Abstract” and gives no page number. (LLM, conf=0.95)

  cites [165] Li, Y.Z., Li, Y.B., Pei, A., et al.: Atomic structure of sensitive battery materials and interfaces revealed by cryo-electron microscopy. Science 358, 506–510 (2017). https://doi.org/10.1126/science.aam6014 source
• ?Not checked — no full text of the sourcecites [167] Aurbach, D., Ein-Ely, Y., Zaban, A.: The surface chemistry of lithium electrodes in alkyl carbonate solutions. J. Electrochem. Soc. 141, L1–L3 (1994). https://doi.org/10.1149/1.2054718 source

In the paper

“when cycled between 3.0 and 4.3 V at -20 °C, the cell using LiFSI additive delivered ~ 30% higher capacity than the baseline electrolyte at all rates of 0.1 C, 0.2 C, 0.5 C, 1 C, and 2 C.”

What the sources say

• Partly supported

  The Fig. 4 rate-capability discussion reports higher discharge capacities with LiFSI at every listed rate between 0.1 C and 2 C, under −20 °C and between 3.0 and 4.3 V. Its reported values imply increases of about 34% at 0.1 C and 39–46% at the other listed rates, so the claim’s “~30% higher” magnitude does not fit all rates. The supplied passage does not specify a page. (LLM, conf=0.89)

  cites [139] Pham, H.Q., Chung, G.J., Han, J., et al.: Interface stabilization via lithium bis(fluorosulfonyl)imide additive as a key for promoted performance of graphite‖LiCoO2 pouch cell under − 20 °C. J. Chem. Phys. 152, 094709 (2020). https://doi.org/10.1063/1.5144280 sourceExperimental — accuracy not yet measured

In the paper

“This resulted in the largest discharge capacity in a graphite||LiCoO 2 cell using the ternary electrolyte (Fig. 4b).”

What the sources say

• ?Not checked — no full text of the sourcecites [20] Smart, M.C., Ratnakumar, B.V., Surampudi, S.: Electrolytes for low-temperature lithium batteries based on ternary mixtures of aliphatic carbonates. J. Electrochem. Soc. 146, 486–492 (1999). https://doi.org/10.1149/1.1391633 source

In the paper

“Therefore, in order to effectively improve the LT performance of a LIB, one must simultaneously improve both charge transfer kinetics and bulk electrolyte ionic conductivity.”

In the paper

“Smart et al. [22] at Jet Propulsion Laboratory developed a ternary LT electrolyte consisting of 1.0 M LiPF 6 in EC:ethyl methyl carbonate (EMC):methyl propionate (MP) (20:60:20 in volume ratio), which has enabled several NASA missions when incorporated into mesocarbon microbead (MCMB)-graphite-LiNiCoAlO 2 (NCA) cells where good performance was required for charging and discharging from -30 to 35 °”

What the sources say

• ?Not checked — no full text of the sourcecites [22] Smart, M.C., Ratnakumar, B.V., Ewell, R.C., et al.: The use of lithium-ion batteries for JPL’s Mars missions. Electrochim. Acta 268, 27–40 (2018). https://doi.org/10.1016/j.electacta.2018.02.020 source

In the paper

“Therefore, the freezing point of different electrolytes can be tuned by adjusting the composition and the content of the solvent.”

In the paper

“The widely used EC is based on its high dielectric constant and excellent SEI formation capability.”

In the paper

“This electrolyte demonstrated excellent compatibility with both LMA and graphite anode at wide-temperature range with fast charging rates.”

What the sources say

• ?Not checked — no full text of the sourcecites [46] Yang, Y., Fang, Z., Yin, Y., et al.: Synergy of weakly-solvated electrolyte and optimized interphase enables graphite anode charge at low temperature. Angewandte Chemie Int. Ed. 61, e202208345 (2022). https://doi.org/10.1002/anie.202208345 source

In the paper

“Therefore, it is the interphasial process, rather than the bulk process, that has the dominant influence on the overall LT electrochemical performance.”

In the paper

“Linear carbonates and carboxylic esters are always desirable for LT electrolytes, owing to their low viscosity and low melting points (Fig. 3).”

In the paper

“In addition to the tunable freezing point, the multi-solvent system owns a higher conductivity than the single-solvent system at LTs due to the disordered effect of Li + coordination in various mixed solvents [19].”

What the sources say

• ?Not checked — no full text of the sourcecites [19] Dong, X.L., Wang, Y.G., Xia, Y.Y.: Promoting rechargeable batteries operated at low temperature. Acc. Chem. Res. 54, 3883–3894 (2021). https://doi.org/10.1021/acs.accounts.1c00420 source

In the paper

“However, the high viscosity and high freezing point (36.4 °C) of EC negatively affect the ionic conductivity, especially at room or low temperatures.”

In the paper

“The electrolyte engineering has proved to be one of the most effective approaches to mitigate LIB performance degradation at LTs.”

In the paper

“During the whole charge transfer process, desolvation is identified to be the most sluggish step with the highest energy barrier to be overcome in many systems.”

What the sources say

• ?Not checked — no full text of the sourcecites [10] Xu, K., von Cresce, A., Lee, U.: Differentiating contributions to “ion transfer” barrier from interphasial resistance and Li+ desolvation at electrolyte/graphite interface. Langmuir 26, 11538–11543 (2010). https://doi.org/10.1021/la1009994 source

In the paper

“Under such context, the LT limit of electrolyte may not be provided by the lowest melting linear carbonate.”

In the paper

“The effect of low t Li + would become especially pronounced at high charge/discharge rates [9].”

What the sources say

• ?Not checked — no full text of the sourcecites [9] Qian, Y.X., Chu, Y.L., Zheng, Z.T., et al.: A new cyclic carbonate enables high power/low temperature lithium-ion batteries. Energy Storage Mater. 45, 14–23 (2022). https://doi.org/10.1016/j.ensm.2021.11.029 source

In the paper

“The lithium metal (Li 0 ) plating and dendrite formation on the graphite anode surface, both caused by the increased anode polarization at low temperatures (LTs), can cause severe capacity loss and internal short circuit.”

In the paper

“Thus, linear carbonates with low melting points and low viscosity are always introduced as cosolvents to address these issues.”

In the paper

“Unfortunately, the most widely used electrolyte solvent, EC, has a high melting point (36.4 °C), which is responsible for the significantly increased electrolyte viscosity at LTs.”

In the paper

“and similarly, the more delocalized the charges on the anions are, the less likely they would reassociate with the cations after the salt dissolution.”

In the paper

“Xiao et al. [26] systematically compared the different content ratios of EC:DMC:EMC systems and achieved 90% capacity at -40 °C with the optimized solvent ratio (EC:DMC:EMC, 8.3:25:66.7 in weight ratio).”

What the sources say

• ?Not checked — no full text of the sourcecites [26] Xiao, L.F., Cao, Y.L., Ai, X.P., et al.: Optimization of EC-based multi-solvent electrolytes for low temperature applications of lithium-ion batteries. Electrochim. Acta 49, 4857–4863 (2004). https://doi.org/10.1016/j.electacta.2004.05.038 source

In the paper

“In addition to ion transport properties, SEI properties vary with the type of linear carbonates introduced.”

In the paper

“In addition to bulk transport properties, Li + transport through solid electrolyte interphase (SEI) is often a limiting factor at LTs.”

In the paper

“When the salt concentration is 4 M, the Li/LiNi 0.5 Mn 1.5 O 4 (LNMO) cell maintained 80.85% of its RT specific discharge capacity even at the LT of -50 °C.”

What the sources say

• ?Not checked — no full text of the sourcecites [45] Feng, T.T., Yang, G.Z., Zhang, S., et al.: Low-temperature and high-voltage lithium-ion battery enabled by localized high-concentration carboxylate electrolytes. Chem. Eng. J. 433, 134138 (2022). https://doi.org/10.1016/j.cej.2021.134138 source

In the paper

“However, the ion transport across electrode/ electrolyte interphases plays comparable or even more important roles [5].”

What the sources say

• ?Not checked — no full text of the sourcecites [5] Zhu, G.L., Wen, K.C., Lv, W.Q., et al.: Materials insights into low-temperature performances of lithium-ion batteries. J. Power Sources 300, 29–40 (2015). https://doi.org/10.1016/j.jpowsour.2015.09.056 source

In the paper

“In a paper published in 2015, a LIB was reported to have a significant capacity drop down to about one fifth of its RT capacity at -30 °C [5].”

What the sources say

• ?Not checked — no full text of the sourcecites [5] Zhu, G.L., Wen, K.C., Lv, W.Q., et al.: Materials insights into low-temperature performances of lithium-ion batteries. J. Power Sources 300, 29–40 (2015). https://doi.org/10.1016/j.jpowsour.2015.09.056 source

In the paper

“According to the phase diagrams constructed for the binary systems of these cyclic and linear carbonates, the liquidus lines, which serve as a demarcation between stable liquid electrolyte and onset for solid precipitation, depend not only on the low melting temperature of the individual components, but also on how much these melting temperatures”

In the paper

“As expected, the electrolyte ionic conductivity drops at LTs because of the increased viscosity, rendering sluggish Li + migration in the bulk electrolyte.”

In the paper

“As reported in early 2000, most graphite anode materials can only deliver 12% of room-temperature (RT) capacity when both lithiation and delithiation were carried out at -20 °C [3].”

What the sources say

• ?Not checked — no full text of the sourcecites [3] Zhang, S.S., Xu, K., Jow, T.R.: Low temperature performance of graphite electrode in Li-ion cells. Electrochim. Acta 48, 241–246 (2002). https://doi.org/10.1016/S0013-4686(02)00620-5 source

In the paper

“It should be noticed that this is the first attempt to use LHCE for high-voltage Li/LNMO system at LTs.”

What the sources say

• ?Not checked — no full text of the sourcecites [45] Feng, T.T., Yang, G.Z., Zhang, S., et al.: Low-temperature and high-voltage lithium-ion battery enabled by localized high-concentration carboxylate electrolytes. Chem. Eng. J. 433, 134138 (2022). https://doi.org/10.1016/j.cej.2021.134138 source

In the paper

“Otherwise, Li + transport inside the SEI still plays a significant role in Li + charge transfer kinetics.”

In the paper

“These challenges primarily come from the anode side.”

In the paper

“These low melting point and low viscosity linear carbonates with stable SEI formation abilities are good candidates as cosolvents and even main solvents for LT applications.”

In the paper

“Compared to the two binary electrolytes of 1 M LiPF 6 in EC:DMC (30:70) and 1 M LiPF 6 in EC:DEC (30:70), the ternary electrolyte of 1 M LiPF 6 in EC:DMC:DEC (1:1:1) showed the highest ionic conductivity at -20 °C due to synergistic effect as shown in Fig. 4a.”

What the sources say

• ?Not checked — no full text of the sourcecites [20] Smart, M.C., Ratnakumar, B.V., Surampudi, S.: Electrolytes for low-temperature lithium batteries based on ternary mixtures of aliphatic carbonates. J. Electrochem. Soc. 146, 486–492 (1999). https://doi.org/10.1149/1.1391633 source

In the paper

“The combination of salts and solvents can influence the transport kinetics of the electrolyte [6].”

What the sources say

• ?Not checked — no full text of the sourcecites [6] Xu, K.: Nonaqueous liquid electrolytes for lithium-based rechargeable batteries. ChemInform 35, 5 (2004). https://doi.org/10.1002/chin.200450271 source

In the paper

“Moreover, the MA-based EC-free electrolyte developed by Zhang's group shows exceptional LT performance [47].”

What the sources say

• ?Not checked — no full text of the sourcecites [47] Yao, Y.X., Yao, N., Zhou, X.R., et al.: Ethylene-carbonate-free electrolytes for rechargeable Li-ion pouch cells at sub-freezing temperatures. Adv. Mater. 34, 2206448 (2022). https://doi.org/10.1002/adma.202206448 source

In the paper

“bis(2,2,2-trifluoroethyl) ether (BTFE) as the diluent, which allows for the modulation of the degree of ion-pairing while maintaining a relatively low bulk viscosity [58].”

What the sources say

• ?Not checked — no full text of the sourcecites [58] Holoubek, J., Kim, K., Yin, Y.J., et al.: Electrolyte design implications of ion-pairing in low-temperature Li metal batteries. Energy Environ. Sci. 15, 1647–1658 (2022). https://doi.org/10.1039/D1EE03422G source

In the paper

“As shown in Fig. 9b, SEIs formed by the fluorinated linear carbonates have lower impedance than conventional EC-DEC-based electrolytes.”

In the paper

“By adding EG as additive, the LT rate performance of LiFePO 4 cathode at -20 °C has been successfully optimized due to the improved ionic mobility [82].”

What the sources say

• ?Not checked — no full text of the sourcecites [82] Tron, A., Jeong, S., Park, Y.D., et al.: Aqueous lithium-ion battery of nano-LiFePO4 with antifreezing agent of ethyleneglycol for low-temperature operation. ACS Sustain. Chem. Eng. 7, 14531–14538 (2019). https://doi.org/10.1021/acssuschemeng.9b02042 source

In the paper

“This work suggested that the ionic conductivity of polymer electrolytes is largely affected by the liquid electrolyte components.”

What the sources say

• ?Not checked — no full text of the sourcecites [72] Smart, M.C., Ratnakumar, B.V., Behar, A., et al.: Gel polymer electrolyte lithium-ion cells with improved low temperature performance. J. Power Sources 165, 535–543 (2007). https://doi.org/10.1016/j.jpowsour.2006.10.038 source

In the paper

“The Li||LiNi 0.8 Co 0.15 Al 0.05 O 2 cell can be cycled well using a cutoff voltage of 4.3 V for charging.”

What the sources say

• ?Not checked — no full text of the sourcecites [62] Fan, X.L., Ji, X., Chen, L., et al.: All-temperature batteries enabled by fluorinated electrolytes with non-polar solvents. Nat. Energy 4, 882–890 (2019). https://doi.org/10.1038/s41560-019-0474-3 source

In the paper

“Considering all these parameters, LiPF 6 represents an excellent balanced property compared to other salts, such as LiBF 4 , LiClO 4 , and LiAsF 6 .”

In the paper

“In another work reported by Liu's group [86], sulfolane (SL) was selected as the cosolvent of antifreeze and the activity inhibitor of water, because of its low toxicity, high miscibility with water, high oxidation stability and strong interaction with water molecules.”

What the sources say

• ?Not checked — no full text of the sourcecites [86] Liu, J.H., Yang, C., Chi, X.W., et al.: Water/sulfolane hybrid electrolyte achieves ultralow-temperature operation for high-voltage aqueous lithium-ion batteries. Adv. Funct. Mater. 32, 2106811 (2022). https://doi.org/10.1002/adfm.202106811 source

In the paper

“However, excessively large anions can lead to low mobility which is adverse for ion transport, which can be seen in the examples of bis[(pentafluoroethyl)sulfonyl]imide (BETI) or other poly-TFSI anions.”

In the paper

“For example, Smart et al. [64] studied a series of fluorinated linear carbonates and found that these electrolytes were able to deliver much higher capacity than the non-fluorinated analogues at -20 °C (Fig. 9a).”

What the sources say

• ?Not checked — no full text of the sourcecites [64] Smart, M.C., Ratnakumar, B.V., Ryan-Mowrey, V.S., et al.: Improved performance of lithium-ion cells with the use of fluorinated carbonate-based electrolytes. J. Power Sources 119(120/121), 359–367 (2003). https://doi.org/10.1016/S0378-7753(03)00266-0 source

In the paper

“Armand et al. [54] proposed a family of “hindered glymes” with bulky groups that prevent solvent co-intercalation due to their larger size and lower binding energy to Li + making the Li + cation desolvation more favorable than co-intercalation.”

What the sources say

• ?Not checked — no full text of the sourcecites [54] Shanmukaraj, D., Grugeon, S., Laruelle, S., et al.: Hindered glymes for graphite-compatible electrolytes. Chemsuschem 8, 2691–2695 (2015). https://doi.org/10.1002/cssc.201500502 source

In the paper

“The gel polymer cell containing electrolyte of 1 M LiPF 6 in EC:DEC:DMC:EMC (1:1:1:3, volume ratio) delivered nearly full (> 99%) RT capacity when discharged at -40 °C using a C/10 rate (Fig. 10a).”

What the sources say

• ?Not checked — no full text of the sourcecites [72] Smart, M.C., Ratnakumar, B.V., Behar, A., et al.: Gel polymer electrolyte lithium-ion cells with improved low temperature performance. J. Power Sources 165, 535–543 (2007). https://doi.org/10.1016/j.jpowsour.2006.10.038 source

In the paper

“LiTFSI and LiFSI salts have attracted a lot of attention recently, due to their high solubility in aprotic solvents enabled by the stabilization of the negative charge provided by the strong electron-withdrawing group (-CF 3 or -F) [6].”

What the sources say

• ?Not checked — no full text of the sourcecites [6] Xu, K.: Nonaqueous liquid electrolytes for lithium-based rechargeable batteries. ChemInform 35, 5 (2004). https://doi.org/10.1002/chin.200450271 source

In the paper

“Moreover, within the widetemperature range, LMBs retained Coulombic efficiencies of 97.3%, 97.2%, 95.2% and 91.0% at 0, -20, -40 and -60 °C, respectively.”

What the sources say

• ?Not checked — no full text of the sourcecites [78] Yin, Y.J., Yang, Y., Cheng, D.Y., et al.: Fire-extinguishing, recyclable liquefied gas electrolytes for temperature-resilient lithium-metal batteries. Nat. Energy 7, 548–559 (2022). https://doi.org/10.1038/s41560-022-01051-4 source

In the paper

“Meng's group [78] recently developed a novel LGE by adding the simplest (liquefied) ether to a non-flammable lowsolvating hydrofluorocarbon mixture.”

What the sources say

• ?Not checked — no full text of the sourcecites [78] Yin, Y.J., Yang, Y., Cheng, D.Y., et al.: Fire-extinguishing, recyclable liquefied gas electrolytes for temperature-resilient lithium-metal batteries. Nat. Energy 7, 548–559 (2022). https://doi.org/10.1038/s41560-022-01051-4 source

In the paper

“Sulfur-containing compounds, such as 1,3,2-dioxathiolane-2,2-dioxide (DTD) and 1,3-propanesultone (1,3-PS), have been extensively studied as electrolyte additives to form stable SEI layers on graphite and suppress graphite exfoliation in PC-based electrolytes.”

In the paper

“Such enhanced performance is attributed to the formation of a thin and stable SEI on the surface of graphite to reduce charge transfer resistance [70].”

What the sources say

• ?Not checked — no full text of the sourcecites [70] Lu, W., Xiong, S.Z., Xie, K., et al.: Identification of solid electrolyte interphase formed on graphite electrode cycled in trifluoroethyl aliphatic carboxylate-based electrolytes for low-temperature lithium-ion batteries. Ionics 22, 2095–2102 (2016). https://doi.org/10.1007/s11581-016-1743-9 source

In the paper

“For example, 1 M LiAsF 6 in EC:EMC:MA:toluene (1:1:1:1, volume ratio) quaternary solvents displayed high ionic conductivity values as 1.830 and 1.100 mS cm -1 at -40 and -50 °C, respectively [94].”

What the sources say

• ?Not checked — no full text of the sourcecites [94] Shiao, H.C., Chua, D., Lin, H.P., et al.: Low temperature electrolytes for Li-ion PVDF cells. J. Power Sources 87, 167–173 (2000). https://doi.org/10.1016/S0378-7753(99)00470-X source

In the paper

“After increasing the discharge rate to C/5, this cell still delivered over 94% of RT capacity.”

What the sources say

• ?Not checked — no full text of the sourcecites [72] Smart, M.C., Ratnakumar, B.V., Behar, A., et al.: Gel polymer electrolyte lithium-ion cells with improved low temperature performance. J. Power Sources 165, 535–543 (2007). https://doi.org/10.1016/j.jpowsour.2006.10.038 source

In the paper

“As a result of the beneficial solvation chemistry and a fluorine-rich environment, a lithium cycling at > 99% Coulombic efficiency for over 200 cycles at 3 mA cm -2 and 3 mAh cm -2 was demonstrated.”

What the sources say

• ?Not checked — no full text of the sourcecites [78] Yin, Y.J., Yang, Y., Cheng, D.Y., et al.: Fire-extinguishing, recyclable liquefied gas electrolytes for temperature-resilient lithium-metal batteries. Nat. Energy 7, 548–559 (2022). https://doi.org/10.1038/s41560-022-01051-4 source

In the paper

“To combine the good ionic conductivity of LiBF 4 and decent SEI formation capability from LiBOB, a LiBF 4 :LiBOB (9:1, molar ratio) dual-salt system was developed by Xu et al. [99,102], in PC/EC/EMC ternary solvent the Li-LiFePO 4 (LFP) cell showed enhanced cyclic performance in a wide-temperature range from -50 to 90 °C.”

What the sources say

• ?Not checked — no full text of the sourcecites [99] Zhang, S.S., Xu, K., Jow, T.R.: Enhanced performance of Li-ion cell with LiBF4-PC based electrolyte by addition of small amount of LiBOB. J. Power Sources 156, 629–633 (2006). https://doi.org/10.1016/j.jpowsour.2005.04.023 source
• ?Not checked — no full text of the sourcecites [102] Xu, K., Zhang, S.S., Lee, U., et al.: LiBOB: is it an alternative salt for lithium ion chemistry? J. Power Sources 146, 79–85 (2005). https://doi.org/10.1016/j.jpowsour.2005.03.153 source

In the paper

“This counter-intuitive difference must be attributed to the different interphases formed from the decomposition of these nitriles.”

In the paper

“The dual-salt electrolyte with a LiBF 4 :LiDFOB ratio of 8:2 enabled LiCoO 2 cathodes with a high capacity retention of 98.67% at -20 °C after 300 cycles.”

In the paper

“Lu et al. also explored electrochemical performance of a graphite anode at different subzero temperatures in an electrolyte with 25% TFENH as cosolvent, and demonstrated that at a relatively higher charge rate of 0.2 C, the graphite anode maintained 92% of RT capacity at -50 °C.”

What the sources say

• ?Not checked — no full text of the sourcecites [70] Lu, W., Xiong, S.Z., Xie, K., et al.: Identification of solid electrolyte interphase formed on graphite electrode cycled in trifluoroethyl aliphatic carboxylate-based electrolytes for low-temperature lithium-ion batteries. Ionics 22, 2095–2102 (2016). https://doi.org/10.1007/s11581-016-1743-9 source

In the paper

“The cell using MB-based electrolytes delivered 80% of its RT capacity when discharged at -60 °C (Fig. 10b).”

What the sources say

• ?Not checked — no full text of the sourcecites [72] Smart, M.C., Ratnakumar, B.V., Behar, A., et al.: Gel polymer electrolyte lithium-ion cells with improved low temperature performance. J. Power Sources 165, 535–543 (2007). https://doi.org/10.1016/j.jpowsour.2006.10.038 source

In the paper

“Ethylene glycol (EG) is a wellknown antifreeze additive with a high dielectric constant (ε = 37 at 25 °C), which can reduce the freezing point of aqueous electrolyte to be lower than -24 °C.”

In the paper

“For these reasons, ethers are usually disfavored as an LT electrolyte solvent for Li + .”

In the paper

“The LGE with oxidation stability up to 4.4 V enabled Li/NMC622 cells exhibiting stable cycling properties from -60 to 55 °C.”

What the sources say

• ?Not checked — no full text of the sourcecites [78] Yin, Y.J., Yang, Y., Cheng, D.Y., et al.: Fire-extinguishing, recyclable liquefied gas electrolytes for temperature-resilient lithium-metal batteries. Nat. Energy 7, 548–559 (2022). https://doi.org/10.1038/s41560-022-01051-4 source

In the paper

“the ionic conductivity is not always compromised since some fluorination may lead to higher dielectric constant.”

In the paper

“Among them, the electrolyte with ethyl-2,2,2-trifluoroethyl carbonate (ETFEC) exhibited the highest delivered capacity [64].”

What the sources say

• ?Not checked — no full text of the sourcecites [64] Smart, M.C., Ratnakumar, B.V., Ryan-Mowrey, V.S., et al.: Improved performance of lithium-ion cells with the use of fluorinated carbonate-based electrolytes. J. Power Sources 119(120/121), 359–367 (2003). https://doi.org/10.1016/S0378-7753(03)00266-0 source

In the paper

“An expanded electrochemical stability window of 3.8 V has been achieved due to the formation of SL contained solvation sheath and strengthen O-H bond of water, inhibiting the decomposition of water.”

What the sources say

• ?Not checked — no full text of the sourcecites [86] Liu, J.H., Yang, C., Chi, X.W., et al.: Water/sulfolane hybrid electrolyte achieves ultralow-temperature operation for high-voltage aqueous lithium-ion batteries. Adv. Funct. Mater. 32, 2106811 (2022). https://doi.org/10.1002/adfm.202106811 source

In the paper

“Moreover, it has been reported that some sulfur-containing additives result in SEI layers that are less resistive [33].”

What the sources say

• ?Not checked — no full text of the sourcecites [33] Wotango, A., Su, W.N., Haregewoin, A.M., et al.: Designed synergetic effect of electrolyte additives to improve interfacial chemistry of MCMB electrode in propylene carbonate-based electrolyte for enhanced low and room temperature performance. ACS Appl. Mater. Interfaces 10, 25252–25262 (2018). https://doi.org/10.1021/acsami.8b02185 source

In the paper

“In addition to the usage of low melting point and low viscosity solvents mentioned above, the application of fluorinated solvents which could significantly improve the interphase chemistry and oxidation stability has also been extensively investigated for LT electrolytes.”

In the paper

“The ionic conductivity is also superior as demonstrated by the fact that even at -85 °C, the cell can still deliver ~ 50 % of its room-temperature capacity.”

What the sources say

• ?Not checked — no full text of the sourcecites [62] Fan, X.L., Ji, X., Chen, L., et al.: All-temperature batteries enabled by fluorinated electrolytes with non-polar solvents. Nat. Energy 4, 882–890 (2019). https://doi.org/10.1038/s41560-019-0474-3 source

In the paper

“Unfortunately, AN has the incompatibility issue with graphite anodes because its reduction product fails to form a solid interphase.”

In the paper

“More importantly, better SEIs could be obtained by using fluorinated electrolytes.”

In the paper

“From the cation-anion dissociation perspective for salt selections, larger anions are more desirable than the smaller ones, because the negative charge is more delocalized, which in turn reduces the Coulombic attraction between counterions.”