Construction of Porous Carbon Nanosheet/Cu 2 S Composites with Enhanced Potassium Storage.

Porous C nanosheet/Cu 2 S composites were prepared using a simple self-template method and vulcanization process. The Cu 2 S nanoparticles with an average diameter of 140 nm are uniformly distributed on porous carbon nanosheets. When used as the anode of a potassium-ion battery, porous C nanosheet/Cu 2 S composites exhibit good rate performance and cycle performance (363 mAh g -1 at 0.1 A g -1 after 100 cycles; 120 mAh g -1 at 5 A g -1 after 1000 cycles). The excellent electrochemical performance of porous C nanosheet/Cu 2 S composites can be ascribed to their unique structure, which can restrain the volume change of Cu 2 S during the charge/discharge processes, increase the contact area between the electrode and the electrolyte, and improve the electron/ionic conductivity of the electrode material.