Mixed-phase 1T/2H-WS2 nanosheets on N-doped multichannel carbon nanofiber as current collector-integrated electrode for potassium battery anode.

Abstract

Potassium-ion batteries (PIBs) have attracted enormous attention due to the increasing lithium battery cost, but their development is still in the pre-mature stage due to the limited selection of electrodes. Herein, a free-standing current-collector-integrated electrode, composed of mixed-phase WS2 nanosheets with nitrogen-doped multichannel carbon nanofibers (N-MCNFs) membrane, is reported for high-performance potassium ion batteries anode. Benefiting the unique multichannel carbon nanostructure as a current collector-integrated electrode as well as mixed-phase lamellar structure WS2 for enhanced potassium ion entry, the 1T/2H-WS2/N-MCNFs hybrid current-collector-free anode delivers an outstanding areal capacity of 2.88 mAh cm-2 (corresponding to 411 mAh/g based on the mass of both electrode and current collector) at a current of 0.7mAcm-2 as well as long-term cycling stability for over 1000 cycles at a high current of 14mAcm-2, surpassing the current state-of-art PIB anode. It is believed that our findings based on the high energy current collector integrated electrode at high mass loading would boost future research on practical metal ion batteries.