四甲基氯化铵添加剂增强金属锌负极性能

Enhancing Stability of Zinc Electrode via Tetramethylammonium Chloride

水系锌离子电池以其高度安全性和低成本等优势具备替代传统铅酸电池的巨大潜力。但是,由于金属锌负极在循环过程中出现表面腐蚀和枝晶生长等不良现象,大大限制其实际应用。因此,提出四甲基氯化铵(tetramethylammonium chloride,TMAC)作为水系锌离子电池的添加剂,TMAC能够提供空间位阻和静电屏蔽的作用,保护了金属锌负极表面,阻碍了腐蚀的产生,抑制了金属锌的枝晶生长。金属锌负极在有TMAC添加剂的电解液中,不出现腐蚀,而没有TMAC添加剂的电解液中,出现了大量的碱式硫酸锌ZSOH腐蚀产物;在对称电池(Zn||Zn)中进行锌的沉积/剥离测试,电解液添加TMAC,超过200 h不发生短路,而没有添加的电解液120 h就出现了短路现象;在全电池(V_(2)O_(5)||Zn)测试中,添加有TMAC电池的比容量超过了没有添加的电池,并且循环寿命也优于没有TMAC的电池。因此,添加TMAC是一种简单有效的改善锌负极电化学性能的方式,从而提高水系锌离子电池的稳定性。

Aqueous zinc-ion batteries possess significant potential to replace conventional lead-acid batteries due to their high level of safety and low cost.However,because of the surface corrosion and dendrite growth of Zn anode during cycle process,its practical application is greatly limited.In this work,a cationic organic compound tetramethylammonium chloride(TMAC) was added into aqueous zinc-ion batteries.TMAC can provide steric hindrance and electrostatic shielding,protect the Zn anode surface,hinder the corrosion reaction,and inhibit the dendrite growth of zinc.The zinc anode,immersed in the electrolyte with TMAC additive,did not show corrosion and the formation of basic zinc sulfate(ZSOH) as a by-product after 7 days,while a large number of ZSOH by-products appeared without TMAC additive.The zinc deposition/stripping testing was carried out in the symmetrical battery(Zn||Zn).When TMAC was added into the electrolyte,short circuit did not occur for more than 200 h,while short circuit occurred in the electrolyte without addition for 120 h.In the full battery(V_2O_5||Zn) testing,the specific capacity of the battery with TMAC exceeded that of the battery without TMAC,and the cycle performance was also better than that of the battery without TMAC.Therefore,adding TMAC is a simple and effective way to improve the electrochemical performance of zinc anode and improve the stability of aqueous zinc-ion batteries.