In situ synthesis of MnO/C nanoparticles anchored on reduced graphene oxide as high-performance zinc ion battery cathode with enhanced zinc storage performance

Aqueous batteries are well-suited for extensive energy storage because of their cost-effectiveness and safety benefits. The zinc electrode, owing to its lower equilibrium potential and higher exchange current density, makes aqueous zinc-ion batteries (ZIBs) a highly promising energy storage device. The advancement of ZIBs hinges on the development and production of sophisticated positive electrode materials that align with the zinc anode and demonstrate outstanding electrochemical performance. Herein the synthesis of MnO/C@rGO composites is achieved by directly anchoring Mn-MOFs on reduced graphene oxide (rGO) sheets, followed by heat treatment in argon and hydrogen atmosphere. As the cathode for ZIBs, in which the graphene oxide promotes the generation of nanoparticles with smaller sizes instead of larger ones and MnO wrapped in a carbon layer are fixed on rGO sheets can not only slow down the manganese dissolution rate but also increase electrical conductivity. These features endow MnO/C@rGO cathode with good cycling stability (85.1 % capacity retention after 1200 cycles at 2 A g−1) and rate performance (318.7 mAh g−1 at 0.2 A g−1). This research achievement will provide new directions for the design and preparation of the anode of ZIBs based on MOFs.