Bioinspired double-layer thermogalvanic cells with engineered ionic gradients for high-efficiency waste heat recovery

Chi, Cheng, Zhang, Xingyu, Shen, Chen, Hu, Qi, Liu, Ze, Hu, Jiahao, Li, Zhi, Li, Yang, Yu, Xiaoli, Xiao, Hao, Zhao, Zhaoquan, Yao, Yuan, Liang, Xing, Wu, Hongwei and Du, Xiaoze (2025) Bioinspired double-layer thermogalvanic cells with engineered ionic gradients for high-efficiency waste heat recovery. Nano Energy, p. 111189. ISSN (print) 2211-2855 (Epub Ahead of Print)

Abstract

Thermogalvanic cells (TGCs) have emerged as a promising technology for harvesting low-grade thermal energy, but their widespread application has been hindered by limited conversion efficiencies. A critical factor in enhancing TGC performance lies in establishing substantial ion concentration gradients, which remains challenging due to the inherent tendency of ion pairing. Here, we present a breakthrough double-layer thermogalvanic cell (DTGC) architecture that spatially segregates redox pairs into two distinct gel layers, enabling unprecedented control over ion concentration gradients. This innovative design yields a single p-type gelatin-K4[Fe(CN)6]/K3[Fe(CN)6] DTGC unit with remarkable performance metrics of an open-circuit voltage of 220 mV, a power density of 1.73 mW m-2 K-2, and a relative Carnot efficiency (ηr) of 1.34% at ΔT = 10 K, representing a tenfold improvement over conventional TGCs. Scaling up this technology, we demonstrate a modular thermoelectric generator comprising a 4×12 array of alternating p-type and n-type DTGCs, capable of delivering an output voltage exceeding 11.3 V at ΔT = 20 K, sufficient to directly power commercial LED lights and electronic displays. This work establishes a new paradigm for efficient low-grade thermal energy conversion, offering a scalable and practical solution for waste heat recovery applications.

Actions (Repository Editors)

Item Control Page Item Control Page