# Fileset

[SI-ver7_DY_2.docx](https://mdr.nims.go.jp/filesets/2743bebb-2850-4272-8e08-e57ac7113479/download)

## Creator

Yiyi Zheng, Jiapei Li, Tian Zhang, Qiaohui Duan, Shuyu Dong, Zhiqiang Guan, Dewu Lin, Wenjun Zhang, [Denis Y.W. Yu](https://orcid.org/0000-0002-5883-7087)

## Rights

[In Copyright](http://rightsstatements.org/vocab/InC/1.0/)

## Other metadata

[A weak-solvation strategy for modulating Li ion solvation sheath to enable fast-charging Li-ion batteries](https://mdr.nims.go.jp/datasets/d6144a40-042b-498b-808c-718b86c8d67f)

## Fulltext

Supplementary DataA weak-solvation strategy for modulating Li ion solvation sheath to enable fast-charging Li-ion batteriesYiyi Zhenga, †, Jiapei Li b, c, †, Tian Zhangb, c, †, Qiaohui Duana, Shuyu Donga, Zhiqiang Guanc,d, Dewu Line, Wenjun Zhangb,c, Denis Y. W. Yuf*a School of Energy and Environment, City University of Hong Kong, Tat Chee Ave, Kowloon, Hong Kong, China.b Center of Super-Diamond and Advanced Films (COSDAF), City University of Hong Kong, Tat Chee Ave, Kowloon, Hong Kong, China.c Department of Materials Science and Engineering, City University of Hong Kong, Tat Chee Ave, Kowloon, Hong Kong, China.d Department of Chemistry, City University of Hong Kong, Tat Chee Ave, Kowloon, Hong Kong, China.e State Key Laboratory of Advanced Waterproof Materials, School of Advanced Materials, Peking University, Shenzhen Graduate School, Shenzhen, China.f Research Center for Energy and Environmental Materials (GREEN), National Institute for Materials Science, Tsukuba, Ibaraki 305-0044, Japan.* corresponding author: yu.denis@nims.go.jp† These authors contributed equally to this work.Figure S1. Raman spectra of (a) MA, (b) EMC, (c) FEMC and (d) FEC and those dissolved with 1 M LiFSI from 400 to 2000 cm-1.Figure S2. Raman spectra of 1 M LiFSI dissolved in different solvents.Figure S3. First charge-discharge curves of the cells using (a) 1 M LiFSI EM with or without FEC electrolyte; (b) 1 M LiFSI FM with or without FEC electrolyte; (c) initial Coulombic efficiency of the cells using different electrolytes.Figure S4. CV curves of the Gr | Li half cells using (a) EMC-based electrolytes and (b) FEMC-based electrolytes. Scan rate: 0.01 mV s-1.Figure S5. (a) Rate performance and (b) corresponding charge-discharge curves of the graphite electrodes with 1 M LiFSI EE electrolyte.Figure S6. (a) Rate performance and (b) corresponding charge-discharge curves of the graphite electrodes with 1 M LiPF6 EM electrolyte.Figure S7. (a) Ionic conductivity and (b) viscosity of different electrolytes.Figure S8. LSV curves of a coin cell with carbon-coated Al foil and Li metal with different electrolytes.Figure S9. O 1s XPS spectra of graphite electrodes after 3 cycles at 0.1 C using different electrolytes. (a) 1 M LiFSI EM electrolyte; (b) 1 M LiFSI FM electrolyte; (c) TE electrolyte; (d) comparison of oxygen-containing substances on the surface of graphite electrodes with different electrolytes. C 1s XPS spectra of graphite electrodes after 3 cycles at 0.1 C using different electrolytes. (e) 1 M LiFSI EM electrolyte; (f) 1 M LiFSI FM electrolyte; (g) TE electrolyte; (h) comparison of carbon-containing substances on the surface of graphite electrodes with different electrolytes.Table S1. RSEI from fitting of the EIS results of the graphite half cells using different electrolytes after cycles at room temperature (typically between 23-24 C).  1 M LiFSI EM 1 M LiFSI FM TE 3 cycles at 0.1 C 37.4 W 29.0 W 71.4 W 3 cycles at 0.1 C        +10 cycles at 4 C 33.3 W 22.8 W 61.7 WNote that the RSEI and Rct for the second row (after 10 cycles at 4 C) differ slightly from the values in Table S2, likely because the room temperature is normally lower than 25 C. Table S2. RSEI from fitting of the EIS results of the graphite half cells using different electrolytes at different temperatures after 10 cycles at 4 Cgraphite. Temperature 1 M LiFSI EM 1 M LiFSI FM TE 5C 101.2 W 50.2 W 390.7 W 15C 55.8 W 22.7 W 151.8 W 25C 22.8 W 12.7 W 64.3 W 35C 14.5 W 10.8 W 24.9 W 45C 3.9 W 4.6 W 11.2 WFigure S10. (a) EIS spectra of the cells with TE after cycles; (b) fitted values of RSEI of graphite electrodes with TE after different cycles. (c) EIS spectra of the cells tested at different temperatures with TE; (d) plot of  vs. 1000 T-1 for graphite | Li half cells with TE.image4.pngimage5.pngimage6.pngimage7.pngimage8.emf1 2 3 4 50.000.010.020.030.040.050.06 1M LiFSI EM 1M LiFSI FMCurrent(mA cm-2)Potential(V vs Li/Li+)image9.pngimage10.pngimage1.pngimage2.emf700 720 740 760 780 800Raman shift (cm-1)Intensity (a.u.)1M LiFSI in FEMC1M LiFSI  in FEC1M LiFSI in MA1M LiFSI in EMCimage3.png