Feng Ziwen, Zhang Yu, Yao Lingmin, Deng Qinglin, Tan Yipeng, Zhao Yang, Li Zelin, Lu Linfei
School of Physics and Materials Science, Guangzhou University, Guangzhou 510006, China.
Research Center for Advanced Information Materials, Huangpu Research & Graduate School of Guangzhou University, Guangzhou 510555, China.
Dalton Trans. 2024 Mar 5;53(10):4501-4511. doi: 10.1039/d3dt04030e.
Aqueous zinc ion batteries (AZIBs) have attracted sustained attention owing to their intrinsic safety and low cost. Unfortunately, the dendrite growth and parasitic side reactions of metallic zinc anodes severely degrade the cycling stability of the batteries and limit the practical application of AZIBs. In this work, calcium gluconate (CG), a chelating agent, as a novel electrolyte additive was introduced to tackle the thorny issue of zinc anodes in a 2 M ZnSO electrolyte by the synergistic effects of gluconate (GA) anions and Ca cations. Experimental characterization and computational simulations confirmed that the incorporation of GA can not only mitigate the precipitation of Ca ions, but also affect the primary solvation shell (PSS) of Zn and modulate the electrode/electrolyte interfacial reaction, thereby inhibiting side reactions. Besides, trace amounts of Ca cations can preferentially adsorb on the surface of the zinc anode tip, forming an electrostatic shielding shell that guides the uniform deposition of zinc ions. The Zn//Zn symmetric cells achieved a remarkably prolonged cycling lifespan ranging from 174 h to 3745 h at 6.37 mA cm and 2.88 mA h cm with an ultrahigh cumulative plating capacity (CPC) of about 11 900 mA h cm. Even at a higher current density of 5 mA cm and an areal specific capacity of 5 mA h cm, Zn//Zn cells with the CG additive cycled for 248 h, about 5 times better than that without the CG additive. These results pave the way for the exploitation of new electrolyte additives with synergistic effects in AZIBs.
水系锌离子电池（AZIBs）因其本质安全和低成本而受到持续关注。不幸的是，金属锌负极的枝晶生长和寄生副反应严重降低了电池的循环稳定性，并限制了AZIBs的实际应用。在这项工作中，引入了一种螯合剂葡萄糖酸钙（CG）作为新型电解质添加剂，通过葡萄糖酸根（GA）阴离子和Ca阳离子的协同作用来解决2 M ZnSO₄电解质中锌负极的棘手问题。实验表征和计算模拟证实，GA的引入不仅可以减轻Ca离子的沉淀，还可以影响Zn的第一溶剂化层（PSS）并调节电极/电解质界面反应，从而抑制副反应。此外，痕量的Ca阳离子可以优先吸附在锌负极尖端表面，形成静电屏蔽壳，引导锌离子均匀沉积。Zn//Zn对称电池在6.37 mA cm⁻²和2.88 mA h cm⁻²的条件下实现了显著延长的循环寿命，从174小时到3745小时，具有约11900 mA h cm⁻²的超高累积镀覆容量（CPC）。即使在5 mA cm⁻²的更高电流密度和5 mA h cm⁻²的面积比容量下，添加CG的Zn//Zn电池也能循环248小时，比不添加CG的电池循环寿命约好5倍。这些结果为开发具有协同效应的新型AZIBs电解质添加剂铺平了道路。
