Han Yuying, Wang Fangzheng, Yan Lijin, Luo Liang, Qin Yuan, Zhu Chong, Hao Jiangyu, Chen Qizhi, Zou Xuefeng, Zhou Yang, Xiang Bin
College of Chemistry and Chemical Engineering, Chongqing University Chongqing 401331 China
College of Chemistry and Chemical Engineering, Chongqing University of Technology Chongqing 400054 China.
Chem Sci. 2024 Jul 2;15(31):12336-12348. doi: 10.1039/d4sc02626h. eCollection 2024 Aug 7.
The poor reversibility of the zinc (Zn) anodes and the irreversible deposition/dissolution of Mn/MnO significantly impede the commercialization of Zn-Mn aqueous batteries (ZMABs). In reducing the difference between the desired interfacial reaction environments of the cathode and anode, we found that they face the same problem of interference-the generation of irreversible corrosion products. Herein, we have introduced a novel self-regulatory mechanism. This mechanism involves the addition of sodium dihydrogen phosphate, which shifts from passive protection to active regulation. It effectively captures OH ions, prevents corrosion product formation, and facilitates the generation of a solid electrolyte interface (SEI) film. This modification also homogenizes Zn ion flow and improves the reversibility of Zn plating and stripping. Furthermore, a stable and slightly acidic environment has been established to stabilize the pH at the cathodic interface, mitigate corrosion product formation, and enhance the reversible deposition and dissolution of Mn/MnO. With the optimal electrolyte, Zn‖Zn symmetric cells demonstrate stable operation for over 3000 hours at 1 mA cm, 1 mA h cm. Additionally, the Zn‖Cu cells maintain high reversibility after 1000 cycles, achieving an average coulombic efficiency (CE) of 99.76%. The assembled Zn‖MnO full cells exhibit exceptional cycling stability and rate performance. This work adopts the approach of seeking common ground and emphasizing the balance of cathode and anode interfacial requirements, which represents a new and significant insight for design of ZMABs with high reversibility and high cyclability.
锌（Zn）负极的较差可逆性以及锰/二氧化锰（Mn/MnO）的不可逆沉积/溶解严重阻碍了锌-锰水系电池（ZMABs）的商业化。在减小正极和负极所需界面反应环境之间的差异时，我们发现它们面临相同的干扰问题——不可逆腐蚀产物的生成。在此，我们引入了一种新型的自调节机制。该机制涉及添加磷酸二氢钠，它从被动保护转变为主动调节。它有效地捕获OH离子，防止腐蚀产物形成，并促进固体电解质界面（SEI）膜的生成。这种改性还使锌离子流动均匀化，并提高了锌电镀和剥离的可逆性。此外，还建立了一个稳定且略呈酸性的环境，以稳定阴极界面处的pH值，减轻腐蚀产物的形成，并增强Mn/MnO的可逆沉积和溶解。使用最佳电解质时，锌||锌对称电池在1 mA cm²、1 mA h cm²的条件下可稳定运行超过3000小时。此外，锌||铜电池在1000次循环后保持高可逆性，平均库仑效率（CE）达到99.76%。组装的锌||MnO全电池表现出优异的循环稳定性和倍率性能。这项工作采用了求同存异的方法，强调了正极和负极界面要求的平衡，这为设计具有高可逆性和高循环性的ZMABs提供了新的重要见解。
