Synergistic Corrosion Engineering on Metallic Manganese Toward High-Performance Electrochemical Energy Storage

MnO/rGO with enhanced electrochemical kinetic properties is widely investigated as electrode for high-performance electrochemical energy storage (EES) devices. However, the synthesis of MnO/rGO via traditional methods suffers from low atomic utilization and complex techniques that are undesirable for practical implementation. Different from existing fabrication strategies, here using metallic manganese as Mn source, a novel, eco-friendly, and corrosion engineering-based approach to address the above issues is demonstrated. It is thermodynamically feasible as supported by the E-pH analysis and for the first time, a significant synergetic effect is observed between NH4+ and GO in strengthening the metallic Mn corrosion reaction. Particularly, in the "ammonia circulation" process, the NH3 molecule, derived from NH4+, acts as a "carrier" for Mn2+ to facilitate its transfer by forming [Mn(NH3)2]2+, which effectively prevents "in situ corrosion". The phase and structure evolution during the reaction are clarified, and the synergistic corrosion mechanism is also proposed. Benefiting from the efficient lithium-ion evolution kinetics, MnOC bond formed between MnO and rGO and outstanding structural integrity, the resultant MnO/rGO demonstrates exceptional EES performances in both lithium-ion batteries and lithium-ion capacitors. This finding will offer potential for mild, cost-effective, and environmentally friendly fabrication of other graphene-based metal oxide electrodes using corrosion engineering. A corrosion engineering-based strategy is employed to construct MnO/rGO as a Li-storage electrode by using metallic manganese as an Mn source. A significant synergetic effect is observed between NH4+ and GO in strengthening the Mn corrosion reaction, and the fundamental synergistic corrosion mechanism is clarified. The obtained material demonstrates exceptional electrochemical energy storage performances in both Li-ion batteries and Li-ion capacitors. image