Positive electrode active material for all-solid-state secondary battery, preparation method thereof, and all-solid-state secondary battery

Abstract

Disclosed are a positive electrode active material for an all-solid-state rechargeable battery, a preparation method thereof and a rechargeable lithium battery, the positive electrode active material which includes a first positive electrode active material including secondary particles including a lithium nickel-cobalt-aluminum-based composite oxide and formed by agglomerating a plurality of primary particles wherein at least a portion of the primary particles are oriented radially, and a buffer layer disposed on the surface of the secondary particles and including a lithium compound and a metal oxide; and a second positive electrode active material including secondary particles including a lithium nickel-cobalt-aluminum-manganese-based composite oxide and formed by agglomerating a plurality of primary particles, and a buffer layer disposed on the surface of the secondary particles and including a lithium compound and a metal oxide, wherein an average particle diameter of secondary particles of the first positive electrode active material is larger than an average particle diameter of the secondary particles of the second positive electrode active material.

Dependencies are inferred from the claim text.