Construction of interfacial electrolyte sieve and fast zinc-conductive channels for high-performance zinc metal anodes

Rampant dendrites and parasitic reactions have been seriously hampering the application of Zn metal anode. The construction of artificial interface layer is considered to be an effective strategy to solve these problems. Herein, we designed an organic-inorganic hybrid interface coating to regulate zinc deposition behavior. The chitin-rich outer layer with abundant polar groups exhibits good zincophilicity, as well as the good trapping ability to SO42- and H2O molecule, thereby promoting the rapid desolvation of Zn2+ and inhibiting the parasitic reactions. The vermiculite-rich inner layer promotes the multi-site nucleation and leads to the uniform deposition of Zn2+, which also works as a tough physical parclose to inhibit dendrite growth. Moreover, according to the experimental results and theoretical calculation, the chitin-vermiculite interface supplies a fast diffusion path with low energy barriers, enabling fast zinc deposition kinetics. As a result, the hybrid coating protected Zn anode (denoted as Zn@VMCT) exhibits high electrochemical reversibility of average CE up to 99.6% in Zn||Cu battery, long plating/stripping lifespan of 2800 h under 1 mA cm-2/1 mAh cm-2 and exceeding 400 h under 10 mA cm-2/10 mAh cm-2 in symmetrical battery. Impressively, when paired with MnO2 cathode, the Zn@VMCT||MnO2 full battery delivers 201.0 mAh g-1 at 1 A g-1 and maintains 92.9% after 800 cycles.