Investigation on safety characteristics of high-nickel lithium-ion cells with anode partially doped by silicon oxide

Abstract

Considering the prospect of lithium-ion cells with graphite + SiOx anode and the fact that there is rare literature concerning the safety features of graphite + SiOx based cells, this work performed an experimental investigation on the safety characteristics of Li(Ni0.8Mn0.1Co0.1)O2/(graphite+10%SiOx) cells with different states of charge (50% SOC, 75% SOC and 100% SOC). Besides that, the impact of two well-known electrolyte additive components, i.e. 2% vinylene carbonate+1% ethylene sulfate (2VC1DTD) and 2% fluoroethylene carbonate+1% lithium difluorophosphate (2FEC1LFO) on the safety characteristics of cells was also revealed. The safety characteristics of Li(Ni0.8Mn0.1Co0.1)O2/(graphite+10%SiOx) cells seem to be worse than Li(Ni0.8Mn0.1Co0.1)O2/graphite cells with the same capacity, the former illustrates larger the maximum temperature rise rate in accelerating rate calorimetry (ARC) tests (16,651 vs. ∼6000 °C/min). Similar to the other types of lithium-ion cells, the safety features of the cells with graphite + SiOx anode enhance with the decrease of cell SOC in typical safety tests. 2VC1DTD and 2FEC1LFO are unable to effectively improve the safety performance of cells under abusive conditions, which might result from the fact that the electrolytes addicted with 2VC1DTD and 2FEC1LFO are flammable as well, and 2VC1DTD and 2FEC1LFO cannot restrain the reactivity between anode materials and electrolytes.