A Novel VW12 POMCPs with π‐π Stacking and Honeycomb 2D Network Structure Accommodated by MXenes as High‐Performance Supercapacitors Negative Electrode

Abstract The key to obtain supercapacitors with high energy density is rational design and synthesis of negative electrode materials. Herein, a new type of polyoxometalate‐based coordination polymer was prepared by one‐step hydrothermal method. Polymer 1 with honeycomb two‐dimensional network structure is beneficial to improve electrical conductivity and storage capacity because of its π‐π stacking interaction. Ti 3 C 2 T x , an MXene material with excellent electrical conductivity, was mixed with compound 1 , which has rich redox reactions. As expected, 1 @Ti 3 C 2 T x exhibited outstanding specific capacitance (768.7 F g −1 at 8 A g −1 ), which is superior to many materials. In addition, the hybrid material also showed good cycle stability (88.1 % capacity retention after 1000 cycles). This work provides an effective way to develop hybrid electrode materials based on polyoxometalate‐based coordination polymers as supercapacitors. In addition, using 1 @Ti 3 C 2 T x as the negative electrode material and celery leaf carbon paper as the positive electrode material, the asymmetric supercapacitor device is fabricated. When the power density is 629.7 W kg −1 , the energy density is 9.2 Wh kg −1 , which indicates that it has a good application prospect.