Anti‐Fatigue and Highly Conductive Thermocells for Continuous Electricity Generation

Abstract

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 ≈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.

Hierarchically Anisotropic Networks to Decouple Mechanical and Ionic Properties for High-Performance Quasi-Solid Thermocells

“…Inspired by the biological tissues, a route to decouple the interdependence of mechanical and ionic properties is to design anisotropic polymer networks, which may not only promote the ion conduction in aligned channels but also enhance the mechanical strength, toughness, and strain-stiffening via hierarchically assembled polymer nanofibrils . In previous studies, a prestretching method is used to create hierarchical fibrils and aligned nanochannels . Nevertheless, the mechanical stretching destroys some amorphous regions, which thus limits the fracture toughness.…”

“…28 In previous studies, a prestretching method is used to create hierarchical fibrils and aligned nanochannels. 31 Nevertheless, the mechanical stretching destroys some amorphous regions, which thus limits the fracture toughness. In contrast, unidirectional freezing is more gentle.…”

Realizing record-high output power in flexible gelatin/GTA-KCl-FeCN4−/3− ionic thermoelectric cells enabled by extending the working temperature range

“…(e) Comparison of the P max /DT 2 with that of the reported liquid-state and quasi-solid-state i-TE cells. 13,17,18,25,[29][30][31][38][39][40][41] Energy & Environmental Science Paper samples undergo an irreversible phase transition at specific temperature points (T M ). T M was significantly enhanced from 30 1C to 40 1C upon introducing 0.8 mM GTA (r v = 3) and then increased to 44 1C upon adjusting r v from 3 to 2.8.…”

Redox-induced thermocells for low-grade heat harvesting: mechanism, progress, and their applications

“…[22][23][24] It's difficult to generate a useful voltage of 1 to 5 V. [25][26][27] Therefore, only a few materials represented by Bi 2 Te 3 have been applied in commercial applications. 28,29 Very recently, there have been several breakthroughs in redox-induced thermocells, which are also called thermo-electrochemical cells, 30 thermocells, 31,32 and thermogalvanic cells. This thermocell is based on ion transport characteristics, offering another cheap, exible, and scalable way to directly convert thermal energy into electrical energy.…”