Decoupled Design for Highly Efficient Perchlorate Anion Intercalation and High-Energy Rechargeable Aqueous Zn-Graphite Batteries.

Seeking new cathode chemistry with high onset potential and compatibility with electrolytes has become a challenge for aqueous Zn ion batteries. Anion intercalation in graphite (4.5 V vs Li+ /Li) possesses the potentiality but usually shows a competitive relationship with oxygen evolution reaction (OER) in aqueous solutions. Herein, a decoupled design is proposed to optimize a full utilization of perchlorate ion intercalation in graphite cathode by pH adjustment. Benefiting from the decoupled design, high Coulombic efficiency is obtained by decelerating the kinetic of OER in acidic media. The decoupled Zn-graphite battery exhibits a wide potential window of 2.01 V, as well as an attractive energy density of 231 Wh kg-1 . In addition, a Zn-graphite battery with SO 4 2 - ${\mathrm{SO}}_4^{2 - }$ insertion is assembled, which demonstrates the capability of the proposed decoupled strategy to integrate novel electrode chemistries for high-performance aqueous Zn-based energy storage systems.