A novel embedded method for in-situ measuring internal multi-point temperatures of lithium ion batteries

Li-ion batteries (LIBs) are the optimal carrier of the renewable energy, while remarkable self-heating can cause performance degradation, even thermal runaway and explosion in the LIBs. Thus, it is important to monitor internal temperature for improving the safety of LIBs. Currently, the inserted temperature sensors induce the electrode damage and capacity degradation of battery, which is not suitable for practical applications. By integrating the multi-point thin film sensor into the LIB electrodes, a novel method is proposed to assemble an integrated battery that remains a stable capacity with high Coulombic efficiency in 100 cycles. The long-term cyclic experimental results show that the inserted thin film sensor has limited impact on the performance of the integrated LIBs. The thin film sensor with electrochemically inert feature demonstrates the internal temperature variation in real-time under different current rates. Consequently, the proposed novel method is used for analyzing failure mechanism and improving safety of Li-ion batteries.