Li-insertion/extraction Properties of Si Thick-film Anodes in Ionic Liquid Electrolytes Based on Bis(fluorosulfonyl)amide and Bis(trifluoromethanesulfonyl)amide Anions

Charge-discharge cycling performances of Si thick-film electrodes as Li-ion battery anodes were investigated in several ionic liquids based on bis(fluorosulfonyl)amide (FSA) and bis(trifluoromethanesulfonyl)amide (TFSA) anions. The Si electrodes in FSA-based electrolytes exhibited much better performance than those in TFSA-based electrolytes. An easier desolvation of Li from anions on the electrode surface is probably promoted in FSA-based electrolytes, which enables efficient electrode reactions of Li-insertion/extraction and improvement of cycling performances.