The sustainable fabrication of δ-MnO2/graphene oxide composites from waste battery graphite via in situ electrochemical exfoliation for supercapacitors and aqueous zinc-ion batteries

Abstract

The in situ electrochemical exfoliation of recycled battery graphite in 1 M Mn²⁺ solution produced defective graphene oxide enriched with carbon–oxygen functional groups and uniformly deposited δ-MnO₂, demonstrating excellent performance in supercapacitors (1126 F g⁻¹ based on CV at v = 1 mV s⁻¹) and aqueous zinc-ion batteries (35 mA h g⁻¹ at 0.4 A g⁻¹).