Cobalt-doped molybdenum disulfide with rich defects and extended layered structure for rechargeable zinc-ion batteries

Zinc-ion batteries (ZIBs) have become potential energy storage devices due to its low cost, environmentally friendly and high safety. The development of ZIBs is facing huge challenges especially in cathode materials. Here, we report a strategy of doping Co into MoS2 to get CoxMo1-xS2 nanosheets with rich dislocation-defects and expanded layer spacing. MoS2 itself has poor Zn2+ diffusivity and low specific capacity due to small layer spacing. The diffusion of Zn2+ is greatly improved by doping of Co. When CoxMo1-xS2 nanosheets are used as positive electrode in ZIBs, the capacity increased from 31.3 mA h g(-1) to 164.1 mA h g(-1), which is increased by more than five times. What's more, even if the current is increased ten times, it still has high capacity (about 40% capacity retention). In addition, the peaks of the Zn2+ intercalation/deintercalation in the CoxMo1-xS2 electrode have been effectively improved, which indicates a much more efficiency Zn2+ intercalation kinetic. Therefore, its capacity has been greatly improved. This research provides a general and effective strategy to reduce the embedding energy barrier of Zn2+ to increase the diffusion rate of Zn2+ and the capacity of ZIBs. (c) 2022 Elsevier B.V. All rights reserved.

Automated summary

This study successfully improved the performance of zinc-ion batteries by doping cobalt into MoS2, increasing the capacity by more than five times, and maintaining a high capacity retention rate.