Two-dimensional copper vanadate intercalated vanadium carbide MXene nanoplates as a high-performance cathode for aqueous Zn-ion batteries

Cathode materials play a crucial role in the energy-storage performances of zinc ion battery (ZIB). In this paper, the two-dimensional vanadium carbide MXene (V2C-MXene) nanoplates intercalated by Cu3V2O7(OH)2·2H2O (CuVO) are synthesized. The intercalation of CuVO in the interlayers of V2C-MXene overcomes self-aggregation of CuVO and improves its structural stability. Meanwhile, the enlarged interlayer spacing of highly conductive V2C-MXene upgrades the electron transfer within the composite. As the cathode electrode of ZIB, the CuVO intercalated V2C-MXene (CuVO@V2C-MXene) battery shows capacity as high as 551.8 mAh g−1 when discharged at 0.5Ag−1. The capacity retention rate reaches 91.8% after 3000 cycles at high current density of 6.0Ag−1. As a comparison, the CuVO//Zn battery has capacity only 193.3 mAh g−1 at 0.5Ag−1, with the capacity retention of just 43.1% after 3000 cycles at 6.0Ag−1. Simultaneously, the CuVO@V2C-MXene//Zn illustrates greatly improved rate capability compared with CuVO//Zn. The CuVO@V2C-MXene composite nanoplates in this work show promise in fabrication of high capacity metal ion batteries.