Reasonable and efficient utilization of low-grade thermal energy in nature is the choice for sustainable energy development. We demonstrate a bacterial cellulose (BC) hydrogel thermocell (TEC) based on BC electrolyte combined with carbon fiber paper and copper composite electrode sheets. The large specific surface area of carbon fiber paper provides a large number of active sites for thermoelectric ions, which drives the redox reaction inside the electrolyte and stimulates the chemical reaction between the electrolyte and the electrode. The combination of the two chemical reactions significantly improves the thermoelectric performance of the thermocell. The thermopower of the BC-TEC reaches 5.9 mV·K⁻¹ at a temperature difference of 50 K. The TEC consisting of 6-units in series produces an open-circuit voltage of about 2 V and a peak power of 535 μW. The TEC shows new potential and prospects in ambient thermoelectric energy conversion by rationally designing the power generation principle.

合理高效利用自然界中低品位热能是能源可持续发展的选择。我们展示了一种基于 BC 电解质与碳纤维纸和铜复合电极片相结合的细菌纤维素 (BC) 水凝胶热电池 (TEC)。碳纤维纸的大比表面积为热电离子提供了大量的活性位点，从而驱动电解液内部的氧化还原反应，激发电解液与电极之间的化学反应。两种化学反应的结合显着提高了热电池的热电性能。BC-TEC的热电势达到5.9 mV·K ^-1在 50 K 的温差下。由 6 个串联单元组成的 TEC 产生约 2 V 的开路电压和 535 μW 的峰值功率。TEC通过合理设计发电原理，在环境热电能量转换方面展现出新的潜力和前景。