The potential risk of thermal runaway,especially overcharging,may lead to safety accidents of Li-ion battery.Based on electrochemical impedance spectroscopy(EIS),the real-time detection of internal battery impedance is achieved by employing single-frequency impedance at X1Hz and X400Hz.After validation under different charging rates,environmental temperatures and states of health,the characteristic impedance demonstrates remarkable stability.Utilizing single-frequency impedance at X1Hz and X400Hz,a thermal runaway safety classification and warning method is proposed,its reliability is verified.The final-stage warning of this method can issue a safety warning more than 5 min before thermal runaway.
维普
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