POSITIVE ELECTROACTIVE MATERIALS FOR ALL-SOLID-STATE BATTERY

The present disclosure provides a positive electroactive material for an electrochemical cell that cycles lithium ions. The positive electroactive material includes a nickel-rich material including a plurality of solid-state particles. Each solid-state particle has a heterogeneous structure that includes a core and a shell that at least partially coats the core. The core includes a nickel-cobalt-manganese material, and the shell includes a nickel-cobalt-aluminum material. When the nickel-rich material is represented by LiNiCoMnAlO, the nickel-cobalt-manganese material is represented by LiNiCoMnO, and the nickel-cobalt-aluminum material is represented by LiNiCoAlO, where (i) 1-x-y-z>0.5, (ii) a+b=1, (iii) zx″+bx″=x, and (iv) 1-x″-(y/a)>1-x″-(z/b). In certain variations, the core and the shell define a base structure, and the heterogeneous structure further includes a buffer layer that at least partially coats the base structure.