Study of thermal runaway and the combustion behavior of lithium-ion batteries overcharged with high current rates

•The thermal runaway characteristics of high current rate overcharged 18,650 lithium-ion batteries were studied.•The thermal runaway processes of lithium-ion batteries were recorded by infrared and visible light cameras.•The combustion and explosion law of two times of thermal runaway was studied.•The higher the current rate, the more intense the thermal runaway reaction of lithium battery.