Printable Carbon‐Based Thermogalvanic Cells

Thermogalvanic cells (TGCs) can convert low‐grade heat directly into electricity through reversible redox reactions induced by temperature gradient. As a unique member of the thermoelectric device family, TGCs provide advantages such as cost‐effective and sustainable materials, a relatively high Seebeck coefficient, and the ability to generate continuous output power. To date, the challenge toward commercializing TGCs lies in developing functional electrode materials that can be produced on a large scale. Herein, the performance of printable activated carbon (AC) as the electrode in TGC is investigated. The multilayer printing of the AC electrodes provides increasing capacitance and improves the maximum output power of the TGC. This is mainly due to the decrease in the device's total resistance thanks to the large surface area of thick AC electrodes. The advanced understanding of the interface between the printed electrode and electrolyte paves the road toward printable and sustainable TGC.