Abstract
Abstract
With metallic lithium serving as the negative electrode material, lithium metal batteries are seen as the most promising next generation of high-specific energy batteries. However, the poor stability of the solid-state electrolyte interface (SEI) caused by the spontaneous interaction between metal lithium and electrolyte during battery cycling exacerbates several problems such lithium dendrite formation, lower Coulomb efficiency, and capacity degradation. The practical use of secondary lithium metal batteries is therefore constrained. Consequently, enhancing SEI stability is a focus of extensive study in the realm of lithium metal batteries. The ideal surface electrode should have strong surface electrical insulation, good lithium-ion conductivity, and high mechanical strength in order to manage the even deposition of lithium ions on the surface, facilitate ion transport, and inhibit dendritic growth. Therefore, constructing a functional SEI film is an effective strategy to solve the challenges faced by lithium metal negative electrodes. This article first introduces the formation mechanism and structural composition of SEI. Then, the failure reasons of SEI were analyzed. Finally, the modification strategy of SEI was emphasized, aiming to provide a reference for the research of metal lithium negative electrodes.