Zhang Xixi, Wang Chenggang, Huang Jinzhao, Li Chuanlin, Qu Guangmeng, Li Na, Zhao Shunshun, Li Titi, Li Dingzheng, Qin Hongjie, Xu Xijin
School of Physics and Technology, University of Jinan, 336 West Road of Nan Xinzhuang, Jinan, 250022, Shandong, P. R. China.
School of Chemistry and Chemical Engineering, Shandong University, Jinan, 250100, P. R. China.
Angew Chem Int Ed Engl. 2024 Dec 16;63(51):e202411884. doi: 10.1002/anie.202411884. Epub 2024 Oct 24.
The inhomogeneous plating/stripping of Zn anode, attributed to dendrite growth and parasitic reactions at the electrode/electrolyte interface, severely restricts its cycling life-span. Here, trace zwitterions (trifluoroacetate pyridine, TFAPD) are introduced into the aqueous electrolyte to construct a multifunctional interface that enhances the reversibility of Zn anode. The TFA anions with strong specific adsorption adhere onto the Zn surface to reconstruct the inner Helmholtz plane (IHP), preventing the hydrogen evolution and corrosion side reactions caused by free HO. The Py cations accumulate on the outer Helmholtz plane (OHP) of Zn anode with the force of electric field during Zn plating, forming a shielding layer to uniformize the deposition of Zn. Besides, the adsorbed TFA and Py promote the desolvation process of Zn resulting in fast reaction kinetics. Thus, the Zn||Zn cells present an outstanding cycling performance of more than 10000 hours. And even at 85 % utilization rate of Zn, it can stably cycle for over 200 hours at 10 mA cm and 10 mAh cm. The Zn||I full cell exhibits a capacity retention of over 95 % even after 30000 cycles. Remarkably, the Zn||I pouch cells (95 mAh) deliver a high-capacity retention of 99 % after 750 cycles.
锌阳极的不均匀电镀/剥离，归因于电极/电解质界面处的枝晶生长和寄生反应，严重限制了其循环寿命。在此，将痕量两性离子（三氟乙酸吡啶，TFAPD）引入水性电解质中，以构建增强锌阳极可逆性的多功能界面。具有强特异性吸附的TFA阴离子附着在锌表面，以重建内亥姆霍兹平面（IHP），防止由游离HO引起的析氢和腐蚀副反应。在锌电镀过程中，Py阳离子在电场力作用下积聚在锌阳极的外亥姆霍兹平面（OHP）上，形成屏蔽层以使锌的沉积均匀化。此外，吸附的TFA和Py促进了锌的去溶剂化过程，从而导致快速的反应动力学。因此，Zn||Zn电池表现出超过10000小时的出色循环性能。即使在锌利用率为85%的情况下，它在10 mA cm和10 mAh cm下仍可稳定循环超过200小时。Zn||I全电池即使在30000次循环后仍表现出超过95%的容量保持率。值得注意的是，Zn||I软包电池（95 mAh）在750次循环后具有99%的高容量保持率。
