Study on thermal runaway characteristics of low-temperature cyclic aging Li-ion batteries
Lithium-ion batteries working at low temperatures will inevitably experience cyclic aging,resulting in performance de-clines such as reduced battery capacity and increased impedance,which will exacerbate the risk of thermal runaway of the battery.In this study,a thermal runaway experiment platform was built to study the thermal runaway characteristics of lithium-ion batteries after cyclic aging at low temperature,and the effects of different aging degrees,charging states and coupling conditions on the ther-mal runaway characteristics of lithium-ion batteries were ana-lyzed.It is found that under-10℃low temperature environ-ment,the time of thermal runaway explosion is advanced,the in-jection is more intense,and the temperature rise rate of the bat-tery is more obvious,but the temperature on the upper part of the battery surface(near the pressure relief valve)decreases with the increase of the number of cycles.Since there is no jet port in the lower part of the battery,the heat accumulation causes the lower part of the battery to be slightly warmer than the upper part.At the same time,the evolution law of voltage and mass loss of the battery under different aging degree and charged state is given.This work helps to improve the understanding of thermal runaway characteristics of aging lithium-ion batteries,and provides theo-retical basis and data support for the safety of lithium-ion batteries operating in low temperature environment.
lithium-ion batterylow-temperature environmentthermal runawaycharge-discharge ratestate of charge
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