This technology forms a crystalline organic electrolyte (SCOE) with a co-crystal structure by combining a sulfone-based solvent and an alkali metal bis(fluorosulfonyl)imide (MFSI) salt in a specific molar ratio. This ensures thermal stability and ionic conductivity at high temperatures, while the melt-casting process improves electrode interface resistance.
Existing organic solid electrolytes, such as those based on succinonitrile, have low melting points below 50°C, leading to instability during high-temperature operation. Furthermore, they suffer from low ionic conductivity and poor wettability with electrodes, resulting in high interface resistance.
This technology creates a crystalline organic solid electrolyte by mixing a sulfone-based solvent with a melting point of 50–170°C and an MFSI salt in a 1:9 to 4:6 molar ratio. By applying this via a melt-casting method—where the electrolyte is melted and poured into the electrode—it reduces interface resistance and maintains physical and chemical stability even at temperatures above 60°C. It can be applied to automotive batteries operating in high-temperature environments, lithium and sodium solid-state batteries, and industrial high-temperature power supplies, effectively resolving the chronic issue of poor interface contact in solid-state batteries by allowing the electrolyte to penetrate deep into electrode pores.
US12537221B2
