solidelectrolyte

Solidelectrolyte refers to a solid-state ion-conducting material used as the electrolyte in electrochemical devices, most notably solid-state batteries. Unlike conventional liquid electrolytes, solid electrolytes conduct ions through a solid lattice or composite, enabling sealed, leak-free cells with potentially improved safety and energy density.

Solid electrolytes are classified by composition and structure. Ceramic solid electrolytes include oxide and sulfide ceramics, such as garnet-type Li7La3Zr2O12 (LLZO) and NASICON-type phosphates Li1+xAlxGe2-x(PO4)3. Sulfide electrolytes, including Li10GeP2S12 (LGPS), offer high room-temperature ionic conductivities but can be moisture-sensitive. Polymer electrolytes, such as polyethylene oxide (PEO) blends, provide flexibility but generally lower conductivities at room temperature. Composite electrolytes mix ceramic and polymer phases to combine properties.

Key performance metrics include ionic conductivity at ambient temperature (targeting 10^-3 to 10^-2 S/cm for practical cells), electrochemical stability window, chemical compatibility with electrodes (notably lithium metal), and mechanical properties that suppress interfacial degradation and dendrite formation.

Advantages of solid electrolytes include improved thermal and chemical safety, reduced risk of leakage, and the possibility of high-energy-density cells with lithium metal anodes. They also enable novel device architectures and longer cycle life in some designs.

Challenges remain, such as high interfacial resistance between solid electrolyte and electrodes, dendrite penetration in some oxide or sulfide systems, brittleness of ceramics, sensitivity to moisture for sulfide-based materials, and difficulties scaling production and achieving cost parity with liquid-electrolyte cells.

Applications are centered on solid-state batteries for electric vehicles and portable electronics, with ongoing research into sodium- and multivalent-based chemistries. The field aims to combine safety, energy density, and manufacturability toward commercial deployment.