Defective ZnO_x@porous carbon nanofiber network inducing dendrite-free zinc plating as zinc metal anode for high-performance aqueous rechargeable Zn/Na₄Mn₉O₁₈ battery based on hybrid electrolyte

Aqueous rechargeable batteries (ARBs) have appealed extensive research interests due to its superiorities of high safety, environmental protection and low redox potential. A Zn/Na₄Mn₉O₁₈ ARB with metal Zn as anode, Na₄Mn₉O₁₈ (NMO) as cathode and Na⁺/Zn²⁺ hybrid-ion as electrolytes has been the focus of attention in recent years. Nevertheless, serious dendrite formation and side reactions impede the application of a Zn anode and the development of the ARBs. In this study, an independent self-supporting defective ZnO_x dispersed porous carbon nanofibers (ZnO_x@PCNF) is designed as the main body of zinc metal anode to solve this problem. It is revealed from ab initio molecular dynamics simulation (AIMD) that ZnO with oxygen defect can promote the surfacely uniform Zn deposition. In this situation, the ZnO_x@PCNF/Zn||Zn symmetrical battery shows high reversibility and free of Zn dendrites. A full cell is assembled by selecting the NMO cathode and ZnO_x@PCNF/Zn anode, and it remains a high reversible capacity of 44.5 mAh g⁻¹ after 200 cycles at 4 C, showing one of the best electrochemical performance of ARBs by using Zn-NMO system. The research has important guiding significance for design and fabricate of defects-containing materials and has a positive impact on the exploitation of high performance ARBs.