Battery technology is undergoing one of the most significant transformations since the lithium-ion cell was commercialized in 1991. Solid-state batteries have moved from laboratory curiosity to near-commercial reality, with major manufacturers including Toyota, Samsung SDI, and CATL racing toward production timelines. But what exactly sets solid-state batteries apart from the lithium-ion cells that power everything from smartphones to electric vehicles today?
What Is a Solid-State Battery? A solid-state battery replaces the liquid electrolyte found in conventional lithium-ion cells with a solid electrolyte material—typically a ceramic, polymer, or sulfide-based compound. In a traditional battery, the liquid electrolyte (a lithium salt dissolved in an organic solvent) serves as the medium through which lithium ions travel between the cathode and anode during charging and discharging. By substituting this flammable liquid with a non-flammable solid, solid-state batteries eliminate one of the most significant safety vulnerabilities in current battery design.
Source: https://www.intelligentliving.co/solid-state-battery-vs-lithium-ion/