Enhancing Zinc-Ion-Transport Kinetics in Solid-State Zinc Batteries via an Internal/Surface Dual Acceleration Strategy
Guobing Sun, Ziyang Cui, Danyang Zhao, Zhixuan Jiao, Ling Li, Zezhan Zhang, Wenming Zhang, Qiancheng Zhu
Abstract
Solid polymer electrolytes (SPEs) hold substantial potential for enabling highly flexible and stable zinc-ion batteries (ZIBs) due to their nearly anhydrous nature. However, the development of SPEs is still hindered by their poor zinc-ion-transport kinetics. Herein, utilizing CALF-20 as both a filler and a functional coating, a bilayer solid-state electrolyte (BSSE) was designed. On the one hand, the intermediate CALF-20 filled poly(ethylene oxide) hybrid gel demonstrates strong interaction with CF 3 SO 3 – anions, thus promoting Zn 2+ dissociation and transmission. On the other hand, the outer single CALF-20 layer supports Zn 2+ ions with abundant transmission paths and a low Zn 2+ migration energy barrier, which doubly accelerates ion migration at the interface. This internal/surface dual acceleration strategy allows the BSSE to deliver high ionic conductivity and Zn 2+ transference number. Both the Zn∥Zn symmetric and Zn∥MnO 2 full cells exhibit an obvious prolonged cycle life. This dual acceleration strategy sheds light on the design of high-ionic-conductivity, steady, and practical ZIBs.