Rational design of interlayer binding towards highly reversible anion intercalation cathode for dual ion batteries

Dual ion batteries are one of the emerging substitutes for lithium ion batteries with high operating voltages and energy density, but their recent advancements have been limited by unsatisfactory cathode stability in the form of irreversible exfoliation. To address this bottleneck, a strategy to selectively incorporate carboxylic anhydride functionality between graphite layers is developed to enforce a stabilizing effect to the crystal structure, which allows for effective performance optimization through particles downsizing and interlayer distance tuning without the compromises of intercalation site disruption and voltage deduction. The resulting graphite cathode experienced significant capacity, rate capability and stability improvements, achieving a highly reversible capacity of 91.2 mAh g−1 at 2 C, which then cycled consistently for over 1,000 cycles. Overall, this work removes a major handicap that has limited the development of dual ion batteries and demonstrates a design pathway for high performance graphite intercalation cathode suitable for anion intercalation with both enhanced stability and discharge capacity.