In situ carbon coated flower-like VPO₄ as an anode material for potassium-ion batteries

Here we design a novel carbon coating method for phosphate-based VPO₄ with three different morphologies, via the intercalation of isobutanol to layered VOPO₄·2H₂O combined with thermal reduction. The well-constructed flower-like VPO₄ delivers a high reversible capacity of 400 mA h g⁻¹ with a long cycle-life of more than 500 cycles, proving that the special structure is suitable to accommodate the large volume expansion during the electrochemical charge–discharge process.