Flexible thermoelectric generators (FTEGs) offer a promising approach to power wearable electronics by harvesting body heat. However, existing materials struggle to combine high flexibility and output power. This paper presents a scalable two-step impregnation method to create a 3D Ag₂Se thermoelectric network with excellent elasticity and superior thermoelectric performance. The network's structure results in ultralight weight (0.28 g cm⁻³), ultra-low thermal conductivity (0.04 W m⁻¹ K⁻¹), softness (0.03 MPa), and high elongation (>100%). The resulting FTEG achieves a high output power of 4 µW cm⁻², comparable to state-of-the-art bulk-based flexible generators. A thermoelectric jacket demonstrates milliwatt-level power generation during daily wear.

Yijie Liu, Xiaodong Wang, Shuaihang Hou, Zuoxu Wu, Jian Wang, Jun Mao, Qian Zhang, Zhiguo Liu, Feng Cao