LAUSR

Abstract The effects of 1 vol% and 2 vol% Fluoroethylene carbonate (FEC) on the electrochemical performance of LiN i0.5 Mn 1.5 O 4 (LNMO) have been investigated, and the results show that the cycling performance and rate capability of LiN i0.5 Mn 1.5 O 4 have been improved. In base electrolyte, the capacities become 91.3 mA h g − 1 with a retention of 82.3% after 150 cycles at 1 C rate. In contrast, after 150 cycles the 1% FEC system reaches 106.7 mA h g − 1 with a 91.1% capacity retention, and the 2% FEC system achieves 113.5 mA h g − 1 with a 96.2% retention. 2% FEC system can even maintain 105.7 mA h g − 1 at 2 C rate. Series of measurements exhibit that the preferential decomposition of FEC is beneficial to form a conductive film, which contains less compositions with low ionic conductivity. What's more, 2% FEC is more useful in forming a uniform and dense film than 1% FEC.