Self-supported hollow-Co3O4@CNT: A versatile anode and cathode host material for high-performance lithium-ion and lithium-sulfur batteries

Inferior specific capacity and sluggish redox kinetics are the most stubborn problems lithium-ion and lithium-sulfur batteries (LIBs and LSBs) are facing, respectively. Here we report a facile fabrication of selfsupported hollow Co3O4 @carbon nanotubes on carbon cloth (H-Co3O4@CNT/CC) through a mild pyrolysisoxidation process. The additive- and binder-free H-Co3O4@CNT/CC shows excellent electrochemical performances as both LIBs and LSBs electrodes. As a robust integrated anode for LIBs, the areal capacities are 2.72 mAh cm -2 at the current density of 0.5 C over 1000 cycles. While as a durable cathode host for LSBs, favorable areal capacities of 2.37 mAh cm(-2) are maintained with a low capacity decay of 0.11 % per cycle at the sulfur loading of 6 mg cm -2 and current density of 1 C after 400 cycles. Electrochemical technology, ex situ Raman spectroscopy and DFT calculations are performed to comprehensively analyze H-Co3O4@CNT/ CC via thermodynamics and kinetics. It is demonstrated that the hierarchically hollow interior structure, strong adsorb ability of Co3O4 toward polysulfides and three-dimensional (3D) inter-connected conductive carbon framework are responsible for the high areal capacity, fast redox kinetics and cycling durability. (C) 2022 Elsevier B.V. All rights reserved.