Flexible zinc-ion microbattery based on a VS2/MXene cathode with high cycle life

Abstract

Aqueous zinc-ion batteries (AZIBs) have attracted considerable attention owing to their high energy density, low cost, and high safety. However, due to their dissolution and lattice collapse, the electrode materials have low rate capacity and poor cycling stability. In this study, a novel VS2/MXene cathode material is fabricated. Owing to the large layer spacing and hydrophobic nature of VS2 as well as the high metallic conductivity of Ti3C2Tx MXene, ionic transfer and electronic diffusion kinetics in VS2/MXene are significantly improved. The VS2/MXene cathodes show excellent cycle life, retaining 93.4% of their capacity after 2400 cycles, and an exceptional capacity of 213.4 mAh g−1 at 0.2 A g−1. Flexible zinc-ion microbattery (ZIMB) assemble with a VS2/MXene cathode and a Zn/MXene anode demonstrates a high capacity of 30.8 μWh cm−2 at a power density of 0.57 mW cm−2 and an ultralong cycle life with almost no capacity reduction after 2000 cycles. This study offers a novel strategy for the effective design of high-performance cathodes and provides potential applications for commercial ZIMBs.