Achieving High Pseudocapacitance of 2D Titanium Carbide (MXene) by Cation Intercalation and Surface Modification

Supercapacitors attract great interest because of the increasing and urgent demand for environment‐friendly high‐power energy sources. Ti 3 C 2 , a member of MXene family, is a promising electrode material for supercapacitors owing to its excellent chemical and physical properties. However, the highest gravimetric capacitance of the MXene‐based electrodes is still relatively low (245 F g −1 ) and the key challenge to improve this is to exploit more pseudocapacitance by increasing the active site concentration. Here, a method to significantly improve the gravimetric capacitance of Ti 3 C 2 T x MXenes by cation intercalation and surface modification is reported. After K + intercalation and terminal groups (OH −…

• NN
  National Natural Science Foundation of China

  Awards: 11275012, 21527803, 21321001, 2013CB933402, 2016YFA0301004, 21471009
• NK
  National Key Research and Development Program of China