Insights into the nitride-regulated processes at the electrolyte/electrode interface in quasi-solid-state lithium metal batteries

Gel polymer electrolytes (GPEs) are one of the promising candidates for high-energy-density quasi-solid-state lithium metal batteries (QSSLMBs), for their high ionic conductivity and excellent interfacial compatibility. The comprehension of dynamic evolution and structure-reactivity correlation at the GPE/Li interface becomes significant. Here, in situ electrochemical atomic force microscopy (EC-AFM) provides insights into the LiNO3-regulated micromechanism of the Li plating/stripping processes upon cycles in GPE-based LMBs at nanoscale. The additive LiNO3 induces the formation of amorphous nitride SEI film and facilitates Li+ ion diffusion. It stabilizes a compatible interface and regulates the Li nucleation/growth at steady kinetics. The deposited Li is in the shape of chunks and tightly compact. The Li dissolution shows favorable reversibility, which guarantees the cycling performance of LMBs. In situ AFM monitoring provides a deep understanding into the dynamic evolution of Li deposition/dissolution and the interphasial properties of tunable SEI film, regulating the rational design of electrolyte and optimizing interfacial establishment for GPE-based QSSLMBs.