Defective ZnOx@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

Abstract

Aqueous rechargeable batteries (ARBs) have appealed extensive research interests due to its superiorities of high safety, environmental protection and low redox potential. A Zn/Na 4 Mn 9 O 18 ARB with metal Zn as anode, Na 4 Mn 9 O 18 (NMO) as cathode and Na + /Zn 2+ 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. 1. Defective ZnO anchored porous carbon nanofibers as the host material for Zn metal. 2. Defective ZnO induces surfacely uniform Zn deposition. 3. NMO||ZnO x @PCNF/Zn full cell shows great electrochemical performance.