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

ABSTRACT 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.