Dry Coating of Electrode Particle with Solid Electrolyte for Composite Electrode of All-Solid-State Battery

Abstract

A dry coating technology to produce composite electrode of an all-solid-state battery has been proposed. First, from the viewpoint of the powder technology, the fundamental concept of the dry coating is introduced. Second, a feasibility study on the dry coating process was conducted by using a cathode active material particle (LiNi_1/3Co_1/3Mn_1/3O₂, NCM) and a model material of sulfide solid electrolyte (Na₂SO₄). The results demonstrated that by means of a dry coating process, single NCM particle was uniformly coated with Na₂SO₄ without any breakage and attrition of the NCM particle. Finally, the dry coating was applied to produce the core–shell-type composite particle with an actual sulfide solid electrolyte (Li₃PS₄, LPS). It was demonstrated that the core–shell composite particle, where single particle of NCM is coated with shell layer of LPS (NCM@LPS), is able to be produced even with Li₃PS₄. A composite cathode prepared with NCM@LPS particles exhibited much larger contact area between NCM and LPS, resulting in significant improvement of rate and cycle performances of an all-solid-state half-cell.