A novel ZnO-based inorganic/organic bilayer with low resistance for Li metal protection

Abstract Although Li metal has a great potential for application as anode of the next generation batteries, the existing problems of the lithium dendrite growth and volume expansion need to be solved to pave the way for the real application of Li metal anode. Here, a double-layer structure consisting of poly(vinylidene fluoride-co-hexafluoropropene) (PVDF-HFP)/ZnO composite membrane and ZnO buffer layer was fabricated by solid-state method and spin coating to protect the Li metal. Compared to the bare Li electrode, the protected Li electrode displays the advantages of stable voltage profiles and long lifespan. Interestingly, the ZnO buffer layer between Li metal and PVDF-HFP/ZnO composite membrane can significantly reduce the battery resistance because of the formation of Li2O on the ZnO nanorod surface, which can guide Li+ flux to deposit uniformly onto Li metal. Results show that the double-layer structure on the Li metal surface can inhibit dendrite growth and volume expansion. The analyses in this paper may contribute to a better understanding of the reaction mechanism between ZnO and Li+.