Emerging demands on heat-durable electronics have accelerated the need for high temperature supercapacitors as well as for understanding the influence of elevated temperatures on the capacitive behavior. In this work, we present a comprehensive study of the thermal influence on a supercapacitor containing 1-ethyl-3-methylimidazolium acetate (EMIM Ac) electrolyte and activated carbon (AC) electrodes. The performance variation as a function of temperature in a range from 21 °C to 150 °C reveals that a high specific capacitance of 142 F g⁻¹ can be achieved at 150 °C at a current density of 2 A g⁻¹ with a rate capability of 87% at 15 A g⁻¹ (relative to 2 A g⁻¹). At 150 °C, equivalent series resistance (ESR) is only 0.37 Ω cm², which is a result of improved ionic conductivity of the electrolyte at elevated temperature. The ESR value of 2.5 Ω cm² at room temperature reflects a good compatibility between EMIM Ac and AC. In addition, a capacitance retention of more than 95% (in the end of 1000 cycles) is maintained up to 120 °C followed by 85% at 150 °C. These results confirm EMIM Ac as a suitable candidate for carbon-based high temperature supercapacitors, and the observations regarding the thermal influence on performance metrics e.g. usable operation voltage could be applicable to other energy storage devices.

对耐热电子器件的新兴需求加速了对高温超级电容器的需求，并加速了高温对电容性能的影响。在这项工作中，我们对包含1-乙基-3-甲基咪唑乙酸盐（EMIM Ac）电解质和活性炭（AC）电极的超级电容器的热影响进行了全面的研究。作为温度在从21℃至150℃的范围内的功能的性能的变化显示，142 F G高的比电容^-1可以在150℃下以2:1的g的电流密度来实现^-1与在15 A g ^-1（相对于2 A g ^-1）时的最大定速能力为87％。在150°C时，等效串联电阻（ESR）仅0.37Ωcm^{如图2所示}，这是在高温下电解质的离子电导率提高的结果。室温下的ESR值为2.5Ωcm ²反映了EMIM Ac和AC之间的良好兼容性。此外，在高达120°C的温度下保持超过95％的电容保持率（在1000个循环结束时），然后在150°C保持85％的电容保持率。这些结果证实了EMIM Ac是碳基高温超级电容器的合适候选者，有关对性能指标（例如可用工作电压）的热影响的观察结果可能适用于其他储能设备。