Effects of Nitriles additives on performances of SiOx/Graphite||NCM811 pouch cell at elevated temperature

Although fluoroethylene carbonate (FEC) additive has been developed to accelerate the commercial process of SiOx/Graphite (SiOx/Gr) composite anode for several years, there are still some challenges need to be solved, such as performance deterioration at elevated temperature, gas and HF generation. In this work, two kinds of nitriles additives are reported to optimize performance of SiOx/Gr||NCM811 pouch cell at high temperature. The introducing of nitriles additives can not only inhibit the decomposition of FEC additive to release HF, but reduce the dissolution of metal ion coming from NCM811 cathode. As a result, an enhanced charge/discharge capacity and rate capability, a reduced polarization resistance are obtained for the SiOx/Gr||NCM811 pouch cell after high temperature storage at 60 degrees C for seven days.