Wu Jianyang, Li Mengchao, Ding Xuan, Chen Zheming, Luo Jing, Zhang Qiaoli, Qiu Yanbin, Wang Qian, Liu Wen, Yang Chengkai
College of Materials Science and Engineering, Fuzhou University, Fuzhou, Fujian, 350108, China.
College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, China.
Small. 2024 Sep;20(38):e2400390. doi: 10.1002/smll.202400390. Epub 2024 May 22.
Gel electrolytes are gaining attention for rechargeable Zn-ion batteries because of their high safety, high flexibility, and excellent comprehensive electrochemical performances. However, current gel electrolytes still perform at mediocre levels due to incomplete Zn salts dissociation and side reactions. Herein, an electrostatic-induced dual-salt strategy is proposed to upgrade gel electrolytes to tackle intrinsic issues of Zn metal anodes. The competitive coordination mechanism driven by electrostatic repulsion and steric hindrance of dual anions promotes zinc salt dissociation at low lithium salt addition levels, improving ion transport and mechanical properties of gel electrolytes. Li ions and gel components coordinate with HO, reducing active HO molecules and inhibiting associated side reactions. The dual-salt gel electrolyte enables excellent reversibility of Zn anodes at both room and low temperatures. Zn||Polyaniline cells using the dual-salt gel electrolyte exhibit a high discharge capacity of 180 mAh g and long-term cycling stability over 180 cycles at -20 °C. The dual-salt strategy offers a cost-effective approach to improving gel electrolytes for high-performance flexible Zn-ion batteries.
凝胶电解质因其高安全性、高柔韧性和优异的综合电化学性能而在可充电锌离子电池领域受到关注。然而，由于锌盐解离不完全和副反应，目前的凝胶电解质性能仍处于中等水平。在此，提出了一种静电诱导双盐策略来升级凝胶电解质，以解决锌金属负极的固有问题。由双阴离子的静电排斥和空间位阻驱动的竞争配位机制促进了在低锂盐添加量下锌盐的解离，改善了凝胶电解质的离子传输和机械性能。锂离子和凝胶成分与羟基配位，减少了活性羟基分子并抑制了相关的副反应。双盐凝胶电解质在室温和低温下均能使锌负极具有优异的可逆性。使用双盐凝胶电解质的锌||聚苯胺电池在-20°C下表现出180 mAh g的高放电容量和超过180次循环的长期循环稳定性。双盐策略为改进用于高性能柔性锌离子电池的凝胶电解质提供了一种经济有效的方法。
