Directing the Preferred Crystal Orientation by a Cellulose Acetate/Graphene Oxide Composite Separator for Dendrite-Free Zn-Metal Anodes

Abstract

The issue of degraded reversibility of zinc-metal anodes resulting from dendrite formation and surface-originated side reactions is still a fundamental challenge for high-performance zinc-ion batteries (ZIBs). Herein, a graphene oxide (GO) nanosheet-modified cellulose acetate (CA) separator is developed with an ultralow mass loading of 4 μg cm −2 by a simple and lowcost filtration method. The low lattice mismatch of GO with Zn metal and numerous hydrophilic O-containing groups of GO enable the uniform Zn nucleation and the following epitaxial electrodeposition along the (002) plane, leading to a dendrite-free surface. Significantly, the surface chemistry of GO is important as the hydrophilic O-containing groups act as the initial nuclei deposition sites, which would grow larger along the parallel direction in the subsequent process. This CA/GO composite separator elevates the symmetric cell lifespan to 500 h at a high current density of 10 mA cm −2 (1 mA h cm −2 ). Moreover, a smaller nucleation overpotential (89 mV at 1 mA cm −2 ) and excellent Coulombic efficiency (higher than 96%) can also be realized. Furthermore, such a separator engineering enables an improved cycling performance for hydrated VO 2 /CC||Zn batteries. This separator modification method provides a pathway for the development of high-performance ZIBs and expands their application in other metal-related energy devices suffering from irreversibility.

Emerging strategies for steering orientational deposition toward high-performance Zn metal anodes

“…Along this line, a cellulose nanofiber–ZrO 2 composite separator was generated by integrating ZrO 2 with a polymethyl cellulose dispersion. 72 Another new type of cellulose acetate separator modified by GO nanosheets was developed by Luo et al 127 Jin and colleagues combined GO and cellulose nanofibers to fabricate a composite CG separator. 43 Such CG separator with abundant zincophilic-O surface groups ensures a strong interaction between the separator and the Zn electrode, thereby allowing the stable contact of GO flakes with the Zn anode.…”

2D Materials Boost Advanced Zn Anodes: Principles, Advances, and Challenges

“…(3) sub + Q e = Zn tried to form composite with 2D nanosheets, achieving an improved ZIB performance [80][81][82][83][84][85][86][87][88][89][90][91][92][93][94][95][96][97].…”

Application of Biomass Materials in Zinc-Ion Batteries

“…The oxygen rich functional groups of graphene can initialize the nuclear deposition sites and have a reversible epitaxial electrodeposition effect. It can also be used to modify the composite cellulose acetate separator to enhance its conductivity [ 113 ]. In addition, by optimizing the preparation process of the biological plasma membrane, biomass nanofibers can also be used to successfully construct ultra-thin and ultra-tough separators with dendrite resistance.…”