Ion-Conductive Dispersant Enabling Scalable Wet-Processed Composite Electrodes for High Performance All-Solid-State Batteries.

While all-solid-state batteries (ASSBs) are promising alternatives to Li-ion batteries due to their non-flammability and high energy density, the lack of scalable electrode-fabrication strategies capable of producing dense composite morphologies remains a major barrier to commercialization. Here, we introduce the concept of an ion-conductive dispersant for sulfide-based composite electrodes and demonstrate lithium dioctyl sulfosuccinate (Li-AOT) as an effective implementation of this strategy. Li-AOT features a Li⁺-coordinated sulfosuccinate headgroup and branched alkyl chains, providing high solubility in low-polarity solvents and strong affinity for sulfide solid electrolytes without compromising ionic conductivity. Unlike conventional nonionic surfactants, Li-AOT integrates into the Li⁺-conduction network rather than forming ion-blocking interlayers, thereby preserving electrolyte conductivity while enhancing electronic percolation via uniform CNT dispersion. Applied to high-loading composite cathodes (20 mg cm⁻²), Li-AOT enables dense, void-lean microstructures with reduced interfacial resistance and polarization, resulting in improved rate capability. This work establishes a generalizable design paradigm for ion-conductive dispersants, offering a scalable pathway to bridge slurry-based wet processing and high-performance sulfide-based ASSBs.