US EPA

8791256 

Journal Article 

Deep eutectic solvent-immobilized PVDF-HFP eutectogel as solid electrolyte for safe lithium metal battery 

Li, Z; Zhang, S; Jiang, Z; Cai, Dan; Gu, C; Tu, J 

2021 

1 

Materials Chemistry and Physics
ISSN: 0254-0584
EISSN: 1879-3312 

267 

10.1016/j.matchemphys.2021.124701 

WOS:000662833200002 

A novel cheap eutectogel (ETG) membrane based on the deep eutectic solvent (DES) immobilized poly (vinylidene fluoride-hexafluoro propylene) (PVDF-HFP) is proposed as a solid electrolyte for safe lithium metal batteries in this study. The composition of DES is optimized, which is prepared by mixing the N-methylacetamide (NMAC) and the lithium bis [(trifluoromethyl)sulfonyl]imid (LiTFSI) with a molar ratio of 4:1. The eutectogel is formed by incorporating 70 wt% DES into the PVDF-HFP, which is non-flammable and shows excellent mechanical properties. This ETG membrane electrolyte with a thickness about 25 mu m possess a high ionic conductivity (3.05 x 10-4 S cm- 1) at room temperature and a wide electrochemical stability window (-5 V). The Li//ETG//LiFePO4 full cells deliver an acceptable discharge capacity of -133.9 mAh g-1 at 0.1C and room temperature after 100 charge-discharge cycles. The ETG membrane electrolyte can also endow the Li//ETG// LiFePO4 pouch cell with flexibility and withstanding abuse operations, like nail penetration and cutting. We expect that the flexible and non-flammable eutectogel membrane will have implications for the use of DES based ionic liquids in the synthesis of advanced solid-state electrolytes for safer lithium batteries. 

Eutectogel; Deep eutectic solvent; Solid-state batteries; Flexible