Study on thermal stability of nickel-rich/silicon-graphite large capacity lithium ion battery

Abstract The nickel-rich silicon-graphite lithium-ion cells, for example the LiNi 0.8 Mn 0.1 Co 0.1 O 2 / Silicon-carbon (NMC811/Si@C), have been used in the commercial power batteries to meet the higher capacity requirements now. However, the battery with higher energy is more destructive as thermal runaway occurs. In order to improve the safety of the battery, it is essential to study the thermal stability of this kind of battery. In this work, the differential scanning calorimetry (DSC) and adiabatic rate calorimetry (ARC) have been used to conduct a detail thermal stability analysis for this type of battery of different charge state, the thermal stability mutation of Si@C material has been observed firstly when the SOC is great than 55%. Besides, a reasonable thermal runaway reaction sequence of the battery of NMC811/Si@C is proposed. Moreover, based on the time to maximum reaction rate (TMR), the effective recommendations for the use of NMC811/Si@C lithium ion battery are provided.