Nanocellulose/graphene films guiding two-dimensional Zn deposition for high cycling stability of Zn anodes.

Abstract

Aqueous zinc-ion batteries (ZIBs) have emerged as attractive alternatives to conventional lithium-ion battery systems, owing to their high theoretical capacity, inherent safety, environmental benignity, and cost effectiveness. However, the long-term stability and practical viability of zinc-ion batteries are impeded by dendritic zinc deposition and concurrent hydrogen evolution reaction (HER). Here, a 2,2,6,6-tetramethyl piperidinyl-1-oxyl (TEMPO)-oxidized cellulose nanofibril/reduced graphene oxide (TOCN/rGO) interlayer was constructed, which can contribute to effective regulation of Zn2+ diffusion along the two-dimensional pathway and isolate Zn anode from water to uniformly guide zinc ions deposition and inhibit the undesirable hydrogen evolution reaction (HER). Compared with bare Zn, the TOCN/rGO@Zn symmetrical battery demonstrates stable cycling performance for over 1000 h at current densities of 0.5 and 2 mA cm-2, while maintaining an exceptionally low overpotential (50 mV). When paired with an MnO₂ cathode, the assembled full cell maintains stable electrochemical performance and remarkable rate capability over repeated cycling. This strategy effectively alleviates dendritic zinc growth and suppresses HER during cycling, thereby offering an alternative pathway toward the practical application of aqueous zinc-ion batteries.