Anti-Fatigue and Highly Conductive Thermocells for Continuous Electricity Generation

The integration of wearable technologies with the human body requires power supplies that are mechanically compatible and able to continuously generate electricity like biological systems. Distinct from existing batteries relying on periodic recharging, thermocells added with thermogalvanic ions are a promising candidate because they enable continuous electricity generation through redox reactions driven by ubiquitous waste heat. However, challenges remain in mechanical adaptability, fatigue resistance, and ion conduction, severely limiting thermocells' sustainability and lifespan in practical applications. Herein, bionic mechanical training is applied to develop anti-fatigue and highly conductive thermocells with hierarchical fibrils and aligned nanochannels. It achieves simultaneous enhancements in mechanical performance and output power density. Compared with existing quasi-solid thermocells with disordered nano-networks, there are approximate to 1790-fold and 5-fold increases in the mechanical toughness and ionic conductivity, respectively. The stretchability can accommodate the human body's deformation, and the power density is comparable to that of state-of-the-art quasi-solid thermocells. Moreover, this is the first demonstration of an anti-fatigue thermocell with a threshold of 2500 J m(-2), which is comparable to that of natural muscles and enables it to take full advantage of the continuous energy conversion mode.

Automated summary

Wearable technologies require power supplies that can generate electricity continuously and are mechanically compatible with the human body. This study successfully developed highly conductive and anti-fatigue thermocells using bionic mechanical training. The thermocells exhibit enhanced mechanical performance and output power density compared to existing thermocells, with improved mechanical toughness and ionic conductivity, as well as good stretchability and power density.