In situ formation of polymer-inorganic solid-electrolyte interphase for stable polymeric solid-state lithium-metal batteries

Composite polymer electrolytes (CPEs) for solid-state Li-metal batteries (SSLBs) still suffer from gradually increased interface resistance and unconstrained Li-dendrite growth. Herein, we addressed the challenges by designing a LiF-rich inorganic solid-electrolyte interphase (SEI) through introducing a fluoride-salt-concentrated interlayer on CPE film. The rigid but flexible CPE helps accommodate the volume change of electrodes, while the polymeric highly concentrated electrolyte (PHCE) surface-layer regulates Li-ion flux due to the formation of a stable LiF-rich SEI via anion reduction The designed CPE-PHCE presents enhanced ionic conductivity and high oxidation stability of >5.0 V (versus Liar). Furthermore, it dramatically reduces the interfacial resistance and achieves a high critical current density of 4.5 mA cm(-2) The SSLBs, fabricated with thin CPE-PHCE membranes (<100 mu m) and Co-free LiNiO2 cathodes, exhibit exceptional electrochemical performance and long cycling stability. This approach of SEI design can also be applied to other types of batteries.

Automated summary

The study addresses the challenges faced by CPEs in SSLBs through the design of a LiF-rich SEI, which improves ionic conductivity and oxidation stability while reducing interfacial resistance and allowing for high critical current density. The fabricated SSLBs show exceptional electrochemical performance and long cycling stability, demonstrating the potential for this SEI design approach to be applied to other battery types.