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

The layered structure V 2 O 5 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 V 2 O 5, and the resulting material, POMA-V 2 O 5 (poly o -methoxyaniline-intercalated V 2 O 5 ), has an ultralarge interlayer distance of 19.34 Å, which is much larger than that of commercial V 2 O 5 (c-V 2 O 5 ) and polyaniline-intercalated V 2 O 5 (PANI-V 2 O 5 ). The discharge capacities of cathodes are highly dependent on their interlayer distance, and the POMA-V 2 O 5 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-V 2 O 5 and PANI-V 2 O 5 cathodes, respectively. Satisfyingly, the Zn//POMA-V 2 O 5 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.