Numerical simulations and thermal behavior analysis for oven thermal abusing of LiCoO_2 lithium-ion battery

Improper design and abusive operations are identified to be major causes related to safety accidents of lithium-ion batteries.A robust and powerful mathematical-physical model based on relevant complex mechanisms that could be an effective tool for thermal analysis,structural design,and thermal management design of lithium-ion batteries is thus a critically requirement.In this paper a thermal abusing model is established particularly for oven tests of graphite/LiPF6 /LiCoO2 batteries to investigate the influence of heat release condition and temperature of oven on battery thermal behaviors by a series of simulations calculation.The simulation results can be applied for detail analysis of battery thermal behaviors.It is found that during abusing processes of oven heat and not leading to thermal runaway,the cathode zone of the battery is the maximum source of heat generation and the rate of heat generation depends mainly on the reaction between intercalated lithium and electrolyte and the decomposition of solid electrolyte interface(SEI);during abusing processes of oven heat and even leading to thermal runaway,the anode zone is the maximum source of heat generation and the rate of heat generation depends mainly on the reaction between anode and solvent.It is also found that the thermal behavior of the battery is dominated by the combined effect of conditions of heat release and oven temperature,the critical temperature of oven for thermal runaway rises with increase of the heat dissipation coefficient,and the critical dissipation coefficient of heat without thermal runaway increases when the oven temperature rises,indicating the importance of thermal design and management of batteries.