Unlocking enhanced capacity and stability: Interlayer polymerization of PEDOT on NH4V4O10 micron-flowers for zinc-ion batteries

Ammonium vanadate (NH 4 V 4 O 10 ) is supposed to be the most potential cathode candidates for aqueous zinc ion batteries (AZIBs) due to its stable layered structure and high theoretical capacity. However, the strong electrostatic interaction between Zn 2+ and NH 4 V 4 O 10 lattice impede its further application. Herein, an efficient hydrothermal method was used to synthesize poly(3, 4-ethylenedioxythiophene) pre-intercalated NH 4 V 4 O 10 (NVO-PEDOT), which shows promising Zn 2+ storage properties as a cathode material for AZIBs. The NVO-PEDOT presents flower-like morphology composed of nanoribbons, which can shorten Zn 2+ diffusion path. Moreover, the pre-intercalated PEDOT introduces oxygen vacancies and low valence vanadium, which not only weaken electrostatic interaction between Zn 2+ and NH 4 V 4 O 10 , but also enhance electronic conductivity, promoting the reversibility of NH 4 V 4 O 10 toward the de−/intercalation of Zn 2+ . Accordingly, NVO-PEDOT cathode provides high reversible capacity (381 mA h g −1 at 0.1 A g −1 after 87 cycles), excellent rate capability (130 mA h g −1 at 20 A g −1 ) and long-life cycling (105 mA h g −1 after 1500 cycles at 10 A g −1 ), confirming the effective synthesis strategy of NH 4 V 4 O 10 cathode for high performance AZIBs.