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 (V 2 C-MXene) nanoplates intercalated by Cu 3 V 2 O 7 (OH) 2 ·2 H 2 O (CuVO) are synthesized. The intercalation of CuVO in the interlayers of V 2 C-MXene overcomes self-aggregation of CuVO and improves its structural stability . Meanwhile, the enlarged interlayer spacing of highly conductive V 2 C-MXene upgrades the electron transfer within the composite. As the cathode electrode of ZIB, the CuVO intercalated V 2 C-MXene (CuVO@V 2 C-MXene) battery shows capacity as high as 551.8 mAh g −1 when discharged at 0.5 A g −1 . The capacity retention rate reaches 91.8% after 3000 cycles at high current density of 6.0 A g −1 . As a comparison, the CuVO//Zn battery has capacity only 193.3 mAh g −1 at 0.5 A g −1 , with the capacity retention of just 43.1% after 3000 cycles at 6.0 A g −1 . Simultaneously, the CuVO@V 2 C-MXene//Zn illustrates greatly improved rate capability compared with CuVO//Zn. The CuVO@V 2 C-MXene composite nanoplates in this work show promise in fabrication of high capacity metal ion batteries.