近日，中南大学方国赵及其研究团队开发了具有界面相容性的转换型阳极化学，用于Ah级近中性高压锌离子电池。2024年5月25日出版的《国家科学评论》杂志发表了这项成果。

据介绍，高安全性近中性电解质的高压水基锌离子电池(AZIBs)在实际应用中具有重要意义，但其存在阳极选择有限和电极/电解质界面不相容的问题。

在该研究中，课题组设计了一种以转化反应的吉布斯自由能变化为指导，具有低阳极电位的转化型阳极化学，用于高压近中性水基锌离子电池中。团队发现了ZnC₂O₄·2H₂O粒子与在CH₃COOLi基电解质中匹配良好的三维Zn金属网络之间的可逆转化反应。这一机制在钠离子或碘离子电池系统中得到普遍验证。

更重要的是，研究人员还提出了一种具有水约束效应的阴极拥挤胶束电解质，它是阴极在2.0 V以上工作平台电压下稳定性和可逆性的核心，在100次循环后容量保持率达到95%。值得注意的是，从硬币电池到Ah级电池的科学和技术挑战，涉及到固-固电极反应动力学缓慢，高负载活性材料下的容量活化，以及与大面积准固体电解质相关的制备复杂性，团队都进行了探索，并成功实现了在超过20 mg cm^-2，特别是实用的1.1 Ah级袋状电池。这项工作为设计低成本、环保和高压的水基电池提供了一条途径。

附：英文原文

Title: Conversion-type anode chemistry with interfacial compatibility toward Ah-level near-neutral high-voltage zinc ion batteries

Author: Guo, Shan, Qin, Liping, Wu, Jia, Liu, Zhexuan, Huang, Yuhao, Xie, Yiman, Fang, Guozhao, Liang, Shuquan

Issue&Volume: 2024-05-25

Abstract: High-voltage aqueous zinc ion batteries (AZIBs) with the high-safety near-neutral electrolyte is of great significance for practical sustainable application, however, it suffers from limited choice of anode and electrode/electrolyte interfacial incompatibility. Herein, a conversion-type anode chemistry with a low anodic potential, which is guided by Gibbs free energy change of conversion reaction, was designed for high-voltage near-neutral AZIBs. A reversible conversion reaction between ZnC2O4·2H2O particles and three-dimensional Zn metal networks well-matched in CH3COOLi-based electrolyte was revealed. This mechanism can be universally validated in the battery systems working by sodium or iodine ions. More importantly, a cathodic crowded micellar electrolyte with water confinement effect was proposed, which lies the core for the stability and reversibility of cathode under an operating platform voltage beyond 2.0 V, obtaining a capacity retention of 95% after 100 cycles. Remarkably, the scientific and technological challenges from the coin cell to Ah-scale battery, pertaining to sluggish kinetics of solid-solid electrode reaction, capacity excitation under high loading of active material, and preparation complexities associated with large-area quasi-solid electrolytes, were explored, successfully achieving an 88% capacity retention under high loading of more than 20 mg cm2 and particularly a practical 1.1 Ah-level pouch cell. This work provides a path for designing low-cost, eco-friendly and high-voltage aqueous batteries.

DOI: 10.1093/nsr/nwae181

Source: https://dx.doi.org/10.1093/nsr/nwae181