Influence of LiFSI on Rate Capability of Lithium-Ion Battery

Lithium bis(fluorosulfonyl)imide (LiFSI) has been investigated as a conducting salt of liquid electrolytes for lithium-ion batteries (LIBs). It shows higher decomposition temperature and Li + conductivity than LiPF 6 . LiNi 1-x-y Co x Al y O 2 (0<x,y<1) is one research focus on LIB cathode materials for its high discharge specific capacity and excellent cycle life. In this article, LiFSI is used as main salt in Li 0.8 Co 0.15 Al 0.05 O 2 (NCA) /graphite LIBs to enhance rate capability. NCA/graphite LIBs with LiPF 6 -based organic electrolyte show 95.3% capacity retention at 1C discharge rate and 89.6% at 3C discharge rate, whereas discharge capacity retention of LiFSI-based ones is 96.7% at 3C.