Aiming at existing problems of battery temperature monitoring technologies

a method based on flexible thin-film sensor technique is presented to monitor the in-situ temperature of lithium ion battery（ LIB）. Polyimide（ PI） is adopted as flexible substrate

and it is implanted into lithium ion pouch cells and internal temperature of battery is charge and discharge test. Experiments show that the embedded thin-film temperature sensor can work stably inside the battery

and the temperature of the LIB is reliably measured.The proposed technique can improve the battery safety and benefit to enhance the understanding of heat generation of the battery.