Thermal runaway has been a long-standing safety issue impeding the development of high-energy-density batteries. Physical safety designs such as employing circuit-breakers and fuses to batteries are limited by small operating voltage windows and no resumption of original working condition when it is cooled down. Here we report a smart thermoresponsive polymer electrolyte that can be incorporated inside batteries to prevent thermal runaway via a fast and reversible sol-gel transition, and successfully combine this smart electrolyte with a rechargeable Zn/α-MnO₂ battery system. At high temperature, battery operation is inhibited as a result of the increased internal resistance caused by the gelation of liquid electrolyte. After cooling down, the electrolyte is spontaneously reversed to sol state and the electrochemical performance of the battery is restored. More importantly, sol-gel transition enables the smart battery to experience different charge-discharge rates under various temperature levels, providing a smart and active strategy to achieve dynamic and reversible self-protection.

热失控一直是阻碍高能量密度电池发展的长期安全问题。对电池采用断路器和保险丝等物理安全设计受到工作电压窗口小和冷却时无法恢复原始工作状态的限制。在这里，我们报告了一种智能热敏聚合物电解质，可以将其结合到电池内部，通过快速可逆的溶胶-凝胶转变来防止热失控，并成功地将这种智能电解质与可充电 Zn/ α -MnO 2相_结合电池系统。在高温下，由于液体电解质的凝胶化导致内阻增加，电池运行受到抑制。冷却后，电解液自发逆转为溶胶态，电池电化学性能恢复。更重要的是，溶胶-凝胶转变使智能电池能够在不同温度水平下经历不同的充放电速率，提供了一种智能和主动的策略来实现动态和可逆的自我保护。