Ionic conductors emerged as the next-generation thermoelectric (TE) materials mainly due to their high thermopower, which is higher than that of the electronic conductors by 1–2 orders in magnitude. However, they cannot be directly used in TE generators (TEGs) because ions cannot transport across the electrodes into the external circuit. Instead, they can be used in ionic TE capacitors (ITECs) to harvest heat. Nevertheless, the ITECs reported in literatures are operated in an intermittent mode, and repeated connection and disconnection to the external load are required. These severely affect their application in practice. Here, we demonstrate the continuous operation of ITECs with the external load always connected. In addition, an equivalent circuit is proposed for the ITECs in the continuous mode, which can account for the TE parameters like the peak voltage and voltage decay time constant. The continuous ITEC can supply comparable power or even higher performance than the control intermittent ITEC, depending on the temperature variation. This work is significant for the practical application of ionic TE materials in heat conversion and the sustainable development of human society.

离子导体作为下一代热电（TE）材料的出现主要是由于其高热电势，比电子导体高1-2个数量级。但是，它们不能直接用于 TE 发生器 (TEG)，因为离子不能通过电极传输到外部电路中。相反，它们可用于离子 TE 电容器 (ITEC) 以收集热量。然而，文献中报道的 ITEC 以间歇模式运行，需要反复连接和断开外部负载。这些严重影响了它们在实践中的应用。在这里，我们演示了 ITEC 在始终连接外部负载的情况下的连续运行。此外，还为连续模式下的 ITEC 提出了等效电路，这可以解释 TE 参数，如峰值电压和电压衰减时间常数。连续 ITEC 可以提供与控制间歇 ITEC 相当的功率甚至更高的性能，具体取决于温度变化。该工作对于离子热电材料在热转换中的实际应用和人类社会的可持续发展具有重要意义。