A polymer pillar for the VOPO4 cathode to retain voltage stability in aqueous zinc batteries

The H₂O-pillared VOPO₄ cathode in aqueous Zn batteries suffers phase transition to low-potential VO_x, causing voltage decay. Replacing interlayer water with poly(3,4-ethylenedioxythiophene) (PEDOT) inhibits this transition via strong PEDOT-VOPO₄ interactions, enabling a stable high voltage of 1.41 V. This work addresses a major challenge of the VOPO₄ cathode for aqueous zinc batteries.