Conductive coating, cation‐intercalation, and oxygen vacancies co‐modified vanadium oxides as high‐rate and stable cathodes for aqueous zinc‐ion batteries
Shandong Tan, Zhiyuan Sang, Zhehan Yi, Jingdong Guo, Xueqi Zhang, Pinxiang Li, Wenping Si, Ji Liang, Feng Hou
Abstract
Abstract Layered vanadium oxides are promising cathode materials for zinc‐ion batteries (ZIBs) owing to their high capacity, but the sluggish electron/ion migration kinetics and structural collapse/dissolution severely limit their Zn 2+ ‐storage performance. Herein, poly(3,4‐ethylenedioxythiophene) coated and Mn 2+ ‐intercalated vanadium oxides with rich oxygen vacancies (MnVOH@PEDOT) are prepared as the cathodes for ZIBs. The PEDOT coating, synergistic with oxygen vacancies, tailors the electron conductivity, and the Mn 2+ ‐intercalation enlarges the interlayer spacing for rapid Zn 2+ ‐ions diffusion. In addition, the pre‐intercalated Mn 2+ ‐ions act as “pillars” to stabilize the structure, and the PEDOT coating prevents the direct contact of vanadium oxides with electrolyte to inhibit its dissolution during cycling. Thus, the MnVOH@PEDOT cathode exhibits superior discharge capacity, favorable rate capability (336.0 mAh g −1 at 8 A g −1 ), and satisfying cyclic durability (84.8% capacity retention over 2000 cycles). This work offers a facile and synergistic design strategy for achieving favorable cathodes for ZIBs. image