Abstract: Positive electrode active material for solid-state batteries, comprising Li, M?, and oxygen, wherein M? comprises: Ni in a content x between 50.0 mol % and 75.0 mol %, Co in a content y between 0.0 mol % and 40.0 mol %, Mn in a content z between 0.0 mol % and 40.0 mol %, dopants in a content a between 0.0 mol % and 2.0 mol %, Zr in a content b between 0.1 mol % and 5.0 mol %, wherein x+y+z+a+b is 100.0 mol %, wherein Zr A = b ( x + y + z + b ) , wherein the positive electrode active material has a Zr content ZrB is expressed as molar fraction compared to the sum of molar fractions of Co, Mn, Ni, and Zr all as measured by XPS analysis, wherein ZrB/ZrA>50.0, the positive electrode active material comprising secondary particles having a plurality of primary particles said primary particles having an average diameter between 170 nm and 340 nm.

Abstract: Positive electrode active material for solid-state batteries, comprising Li, M?, and oxygen, wherein M? comprises: Ni in a content x between 50.0 mol % and 85.0 mol %, Co in a content y between 0.0 mol % and 40.0 mol %, Mn in a content z between 0.0 mol % and 40.0 mol %, dopants in a content a between 0.0 mol % and 2.0 mol %, Zr in a content b between 0.1 mol % and 5.0 mol %, wherein x+y+z+a+b is 100.0 mol %, wherein Zr A = b ( x + y + z + b ) , wherein the positive electrode active material has a Zr content ZrB is expressed as molar fraction compared to the sum of molar fractions of Co, Mn, Ni, and Zr all as measured by XPS analysis, wherein ZrB/ZrA>50.0, the positive electrode active material comprising secondary particles having a plurality of primary particles said primary particles having an average diameter between 170 nm and 340 nm.