不同过充电流下大容量三元锂电池热失控危险性OA

To explore the thermal runaway hazard of overcharging in large-capacity ternary lithium-ion batteries,117 Ah and 153 Ah batteries were studied.Experiments were performed on a large-capacity lithium-ion battery thermal runaway test platform at overcharge currents of 30,45 and 60 A.A compre-hensive assessment of the thermal runaway hazard was performed using the AHP-entropy weight meth-od based on multiple characteristic parameters.The results indicate that:The thermal runaway process of the 117 Ah battery is characterized by four distinct stages.The venting process is not experienced by the 153 Ah battery due to the direct rupture of its casing.The thermal runaway trigger time for both battery types is markedly shortened with increasing overcharge current.For the 117 Ah battery,key hazard parameters including peak temperature,total gas production,and flammable gas content increase with higher current,demonstrating a clear current dependence.In contrast,an opposite trend is shown by the 153 Ah battery,due to differences in its internal structure and reaction time.The main compo-nents of the gases released by thermal runaway are identified as CO,CO2,and H2.The relative content of these gases is influenced by the combined effects of the current and the pressure release method of the battery.The thermal runaway hazard of the 117 Ah battery increases significantly with higher cur-rent.Conversely,a higher hazard is presented by the 153 Ah battery under low current conditions due to prolonged overcharge time.An increased capacity is found to notably reduce the safe current thresh-old of the battery.These findings provide a reference for establishing a differentiated safety system that considers the relationship between battery capacity and current.