Sun Haowen, Li Mengxiu, Zhu Junbing, Ni Jiangfeng, Li Liang
School of Physical Science and Technology, Center for Energy Conversion Materials & Physics (CECMP), Jiangsu Key Laboratory of Frontier Material Physics and Devices, Soochow University, Suzhou 215006, China.
Jiangsu Key Laboratory of Advanced Negative Carbon Technologies, Soochow University, Suzhou 215006, China.
ACS Nano. 2024 Aug 13;18(32):21472-21479. doi: 10.1021/acsnano.4c06252. Epub 2024 Aug 1.
Iodometric and iodimetric titrations represent a prevailing technique to determine the concentration of Cu ions in aqueous solutions; However, their utilization in electrochemical energy storage has been overlooked due to the poor reversibility between CuI and Cu related to the shuttling effect of I species. In this work, we developed a 4A zeolite separator capable of suppressing the free shuttling of I ions, thus achieving a record-high capacity retention of 95.7% upon 600 cycles. Theoretical and experimental studies reveal that the negatively charged zeolite can effectively impede the approach and penetration of I ions, as a result of electrostatic interaction between them. To explore the practical potential, a hybrid cell of Zn∥I consisting of Cu redox agent has been assembled with a discharge capacity of 356 mA h g. The cell affords a specific energy of 443 W h kg based on I, or 193 W h kg based on both electrodes. This work offers insight on the energy utilization of the iodometric reactions and advocates a Cu-mediated cell design that could potentially double the capacity and energy of conventional aqueous battery systems.
碘量滴定法和碘滴定法是测定水溶液中铜离子浓度的常用技术；然而，由于与碘物种的穿梭效应相关的碘化亚铜和铜之间的可逆性较差，它们在电化学储能中的应用一直被忽视。在这项工作中，我们开发了一种能够抑制碘离子自由穿梭的4A分子筛隔膜，从而在600次循环后实现了创纪录的95.7%的高容量保持率。理论和实验研究表明，带负电荷的分子筛能够有效地阻碍碘离子的接近和渗透，这是它们之间静电相互作用的结果。为了探索实际潜力，我们组装了一个由铜氧化还原剂组成的Zn∥I混合电池，其放电容量为356 mA h g。该电池基于碘的比能量为443 W h kg，基于两个电极的比能量为193 W h kg。这项工作为碘量反应的能量利用提供了见解，并倡导一种铜介导的电池设计，这种设计有可能使传统水系电池系统的容量和能量翻倍。
