The Need

The energy density and safety of lithium-metal solid-state batteries (LIMSSBs) are limited by the stability of the interface between the lithium-metal anode and the solid-state electrolyte. Traditional approaches using static interlayers or coatings often fail to maintain continuous contact during cycling, particularly when voids form due to non-uniform lithium plating/stripping.

The Technology

OSU engineers have developed a thin, conformal adaptive polymer interlayer (<10 μm). This interlayer retains the adaptive behavior (expansion under an electric field via conducting polymer particle polarization), minimizes thickness to reduce impedance and preserve energy density, and ensures strong interfacial adhesion to ceramic electrolytes via an innovative synthesis process. A novel synthesis approach was also developed to enable successful integration of the adaptive interlayer into prototype LIMSSB cells, achieving average thicknesses as low as 5 μm and maintaining mechanical stability during synthesis and assembly.

Benefits/Advantages

• Dynamic, self‑adjusting contact: reduces interfacial degradation and dendrite initiation
• Low‑field activation: (threshold ≈0.1–0.2 V/µm) observed in lab; repeatable response; potential to relax stack‑pressure needs
• Process‑friendly path: compatible with industrial coating workflows
• Thin: (<10 µm)