College of Chemistry and Chemical Engineering/Institute of Polymers and Energy Chemistry (IPEC)/Jiangxi Provincial Key Laboratory of New Energy Chemistry, Nanchang University, 999 Xuefu Avenue, Nanchang, 330031, China.
School of Physics and Materials Science, Nanchang University, 999 Xuefu Avenue, Nanchang, 330031, China.
Angew Chem Int Ed Engl. 2023 Jul 3;62(27):e202302701. doi: 10.1002/anie.202302701. Epub 2023 May 24.
Zn metal as one of promising anode materials for aqueous batteries but suffers from disreputable dendrite growth, grievous hydrogen evolution and corrosion. Here, a polycation additive, polydiallyl dimethylammonium chloride (PDD), is introduced to achieve long-term and highly reversible Zn plating/stripping. Specifically, the PDD can simultaneously regulate the electric fields of electrolyte and Zn/electrolyte interface to improve Zn migration behaviors and guide dominant Zn (002) deposition, which is veritably detected by Zeta potential, Kelvin probe force microscopy and scanning electrochemical microscopy. Moreover, PDD also creates a positive charge-rich protective outer layer and a N-rich hybrid inner layer, which accelerates the Zn desolvation during plating process and blocks the direct contact between water molecules and Zn anode. Thereby, the reversibility and long-term stability of Zn anodes are substantially improved, as certified by a higher average coulombic efficiency of 99.7 % for Zn||Cu cells and 22 times longer life for Zn||Zn cells compared with that of PDD-free electrolyte.
锌金属作为水系电池有前景的阳极材料之一，但存在着令人诟病的枝晶生长、严重的析氢和腐蚀问题。在此，引入聚阳离子添加剂聚二烯丙基二甲基氯化铵（PDD）以实现长期且高度可逆的 Zn 电镀/剥离。具体而言，PDD 可以同时调节电解液和 Zn/电解液界面的电场，以改善 Zn 迁移行为并引导主导 Zn（002）沉积，这可通过 Zeta 电位、开尔文探针力显微镜和扫描电化学显微镜得到证实。此外，PDD 还形成了带正电荷的富保护外层和富 N 的混合内层，这加速了电镀过程中 Zn 的去溶剂化，并阻止了水分子与 Zn 阳极的直接接触。因此，Zn 阳极的可逆性和长期稳定性得到了显著提高，Zn||Cu 电池的平均库仑效率高达 99.7%，而无 PDD 电解液的 Zn||Zn 电池寿命延长了 22 倍。
