Solid-state lithium-ion batteries (SLIBS) are expected to be used in next-generation energy storage devices due to their high energy density. However, for the practical application of slibs, it is essential to solve the problems of interface instability and poor electrochemical performance.
Figure 1Schematic diagram and characterization of SEI.
Li Libo, Harbin University of Science and TechnologyA uniform solid electrolyte interface (SEI) film was successfully constructed in situ by using silk fibroin peptide (SFP) and MXENE through interface modification design. The incorporation of the -NH2 group of SFP and the -F terminus of MXENE promoted the formation of Li3N and LIF, resulting in selective localization and controlled SEI film growth, as confirmed by time-of-flight secondary ion mass spectrometry (TOF-SIMS) analysis. In addition, the Derjaguin-Müller-Toporov (DMT) modulus demonstrates the robustness of SEI films, which enhances interfacial stability, promotes lithium-ion nucleation, inhibits dendrite growth, and improves the overall electrochemical performance during battery operation. 
Figure 2Interface studies.
In addition, -NH2 with lone pairs exhibits excellent lithophilic properties, which is conducive to the formation of microcomplexes with lithium ions, thereby promoting the dissociation of lithium salts and accelerating the migration of lithium ions in the system. In addition, the interfacial modification of the polymer electrolyte (PES) has a high of 116 10 3 s cm1 ionic conductivity, the migration number of lithium ions (TLI+) is 057。Notably, the modified PES significantly promoted the stable operation of the cell at room temperature (RT), showing 117 at 5 CInitial discharge capacity of 6 mAh g 1. This innovative strategy of modifying the interface is a major step forward in achieving stable operation of high-energy slibs. 
Figure 3Electrochemical performance studies.
mxene and silk fibroin peptide team up to build a 1+1>2 in situ sei film. energy storage materials 2023. doi: 10.1016/j.ensm.2023.103126