Zhang Wencong, Qiu Liyu, Lian Yongjian, Dai Yongqiang, Yin Shi, Wu Chen, Wang Qianming, Zeng Wei, Tao Xiaoming
Key Laboratory of Theoretical Chemistry of Environment, Ministry of Education, School of Chemistry, South China Normal University, Guangzhou, 510006, China.
The center of flexible sensing technology, Institute of Chemical Engineering, Guangdong Academy of Sciences, Guangzhou, 510665, China.
Adv Sci (Weinh). 2023 Oct;10(29):e2303407. doi: 10.1002/advs.202303407. Epub 2023 Aug 1.
The main obstacle of ionic thermo-electrochemical cells (TECs) in continuous power supply lies in a low heat-to-electricity energy conversion efficiency because most TECs work in thermodiffusion mode in which the ions are confined in a liquid/electrolyte media. The introduction of the redox couple onto the electrode surface may overcome the obstacle by resolving the low mass transport rate of ions caused by the redox process occurring near but not on the electrode surface. Herein, the authors demonstrate enhancement of TECs by integrating the redox couple directly onto the electrode surface to maximize the mass transport efficiency. A discontinuous interfacial modification strategy is developed by using a carbon cloth/iron (II/III) phytate as the symmetric electrodes. The gelled electrolyte consisting of a polyacrylamide matrix and phytic acid is shown to promote selective ion diffusion. A synergistic combination consisting of the thermodiffusion effect and redox reactions on the electrode is established in a pre-treated layout. Such TEC affords a high output voltage of 0.4 V, an excellent instantaneous output power density (20.26 mW m K ) and a record-high 2 h output energy density (2451 J m ) under T = 30 °C with T = 15 °C, with an ultrahigh Carnot-relative efficiency of 1.12%.
离子热电池（TECs）在持续供电方面的主要障碍在于热电能量转换效率较低，因为大多数TECs在热扩散模式下工作，其中离子被限制在液体/电解质介质中。将氧化还原对引入电极表面可能会克服这一障碍，方法是解决因在电极表面附近而非电极表面发生的氧化还原过程导致的离子低质量传输速率问题。在此，作者通过将氧化还原对直接整合到电极表面以最大化质量传输效率，证明了TECs性能的提升。通过使用碳布/植酸铁（II/III）作为对称电极，开发了一种不连续界面修饰策略。由聚丙烯酰胺基质和植酸组成的凝胶电解质被证明可促进选择性离子扩散。在预处理布局中建立了由电极上的热扩散效应和氧化还原反应组成的协同组合。这种TEC在T = 30°C、T = 15°C的条件下，可提供0.4 V的高输出电压、出色的瞬时输出功率密度（20.26 mW m K）和创纪录的2小时输出能量密度（2451 J m），具有1.12%的超高卡诺相对效率。
