High-capacity cathode for aqueous zinc-ion battery based on MnOx-modified bismuth vanadate

Aqueous Zn-ion batteries (AZIBs) are a perspective energy storage technical due to their excellent safety levels while maintaining cost-effectiveness, and large theoretical specific capacity. However, the capability mismatch between cathode and anode brings the low specific capacity and unsatisfactory cycle life, which blocks the large-scale application of AZIBs for renewable energy sources and the smart grid industry. Herein, we constructed a decahedral BiVO 4 /MnO x nanosheets cathode to boost the charge/discharge performance of AZIB by a directional drive strategy. Due to the MnO x nanosheets selectivity growth on {110} facet of decahedral BiVO 4 and the laminar structure of the BiVO 4 /MnO x composite, the channels of electron transfer are established between BiVO 4 and MnO x nanosheets, which restrain the instability of manganese oxides and accelerate the insertion/extraction of Zn 2+ , and further enhance the specific capacity and cycle life of AZIB. The BiVO 4 /MnO x cathode shows a high specific capacity of 567.5 mAh g −1 and the assembled AZIB exhibits an outstanding energy density of 365.5 Wh kg −1 , superior rate performance, stable long cycle life, and superior long-cycle capability (6600 cycles at 3 A g −1 ). The above findings provide a new way for high capacity and high life cathode materials of AZIBs.