Elaborate artificial construction of porous biomass carbon interfacial layer on the surface of zinc anode toward high performance aqueous zinc-ion batteries

Aqueous zinc ion batteries (AZIBs) have emerged as one of the most promising candidates for large-scale energy storage and other fields owing to their low cost, high safety and environmental friendliness. However, the dendritic issue and side reactions induced by the zinc anode-electrolyte interface have always been the major obstacles hindering their development. Herein, porous biomass carbon (BCK) is artificially designed via a simple method to act as an ex-situ surface coating on the zinc anode to resolve the above problems. The interface coating effectively reduces the interface area of direct contact between the zinc anode and electrolyte, thereby suppressing dendrite growth and parasitic reactions. Especially, BCK has a rich pore structure and zincophilic oxygen-containing functional groups, providing sufficient active sites, which can adsorb Zn2+ and preferentially nucleate on the surface of BCK, thus eliminating the tip effect and making the surface of the zinc sheet uniform and flat. In addition, the large specific surface area of BCK can promote the transport and nucleation kinetics of Zn2+, guide the formation of a uniform surface electric field on the zinc anode, enhance the deposition rate of Zn2+ at the anode-electrolyte interface, which helps to guide the uniform nucleation, growth, and deposition of Zn2+. Benefiting from these advantages, the assembled symmetric cells have lower voltage hysteresis and longer cycling performance than bare Zn cells, and the full cell delivers a capacity of 166.5 mAh g-1 and the capacity retention rate of 61.5 % after 1000 cycles at 1 A g-1, which is significantly higher than that of bare Zn assembled full cell.