Method for manufacturing an electrode composite, the electrode composite manufactured thereby, and an all-solid-state battery comprising said electrode composite

Binder-free integrated sulfide electrode composite via wet synthesis using an amine-thiol co-solvent

This technology is a wet synthesis method that produces an argyrodite-structured electrode composite with active materials bonded onto a sulfide-based solid electrolyte. It achieves this by uniformly dissolving and dispersing insoluble precursors and electrode active materials in a co-solvent mixture of amine and thiol solvents, followed by heat treatment.

Conventional wet synthesis methods suffer from non-uniform dispersion due to the low solubility of solid electrolyte raw materials and issues with residual solvents. Furthermore, they require complex electrode manufacturing processes involving the physical mixing of conductive additives, active materials, and electrolytes, which limits ionic conductivity and interfacial stability.

This technology uses a co-solvent of ethylenediamine and ethanedithiol in a 1:0.05–0.5 volume ratio to create a uniform reactant solution. Subsequent heat treatment at 210–800°C forms a composite where the solid electrolyte and active material are interfacially bonded, ensuring high ionic conductivity and adhesion without a binder. It can be applied to the cathode manufacturing of lithium all-solid-state batteries using conversion-type cathodes like FeS2 and sodium all-solid-state batteries based on Na11Sn2PS12, eliminating the need for separate dry mixing processes and increasing the contact area between the active material and electrolyte.

‍

‍

Key Features:

• Step of preparing a precursor mixture containing a lithium-based or sodium-based precursor and a sulfide-based precursor
• Step of preparing a reactant by mixing an electrode active material and the precursor mixture into a co-solvent consisting of an amine-based solvent and a thiol-based solvent in a 1:0.05–1:0.5 volume ratio
• Step of heat-treating the reactant at 210–800°C to produce an electrode composite in which the electrode active material is dispersed and bonded onto a sulfide-based solid electrolyte
• An electrode composite that forms a crystalline argyrodite structure without a binder and contains the electrode active material and the sulfide-based solid electrolyte in a weight ratio of 1:1 to 5:1

‍

This invention was developed with support from the Ministry of Science and ICT for the development of core technologies for R2R-type high-ionic-conductivity functional solid-state electrolyte membranes.

‍