Polymer Configuration Regulates Zinc Storage Capacity of a Layered Vanadium Oxide Cathode

The layered structure V2O5 compound is a typical cathode material for aqueous zinc batteries (AZBs). However, it often suffers from serious dissolution of vanadium and structural collapse, which leads to a poor cycle life. Herein, we employed a poly o-methoxyaniline (POMA) to preintercalate into V2O5, and the resulting material, POMA-V2O5 (poly o-methoxyaniline-intercalated V2O5), has an ultralarge interlayer distance of 19.34 Å, which is much larger than that of commercial V2O5 (c-V2O5) and polyaniline-intercalated V2O5 (PANI-V2O5). The discharge capacities of cathodes are highly dependent on their interlayer distance, and the POMA-V2O5 cathode with a maximum interlayer distance makes for a high initial discharge capacity of 353.8 mAh g–1 at 1 A g–1, which is 2.94 and 1.73 times that of the c-V2O5 and PANI-V2O5 cathodes, respectively. Satisfyingly, the Zn//POMA-V2O5 battery has long cycle stability and can still maintain a capacity of 186.8 mAh g–1 after 10,000 cycles at 10 A g–1. The regulating strategy proposes a new approach for further designing high-performance intercalation compounds of AZB cathodes.