LITHIUM ION SECONDARY BATTERY

• Main Authors: OCHIAI TERUAKI, TAKAHASHI MASAHIRO, MONMA YOHEI, TSURUTA SAE
• Format: Patent
• Language: English; Japanese
• Published: 02.04.2024
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRICITY; PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSIONOF CHEMICAL INTO ELECTRICAL ENERGY

To provide a positive electrode active material particle that deteriorates less, a power storage device with little deterioration, alternatively, a highly safe power storage device.SOLUTION: A positive electrode active material particle includes a first crystal grain, a second crystal grain, and a grain boundary located between the first crystal grain and the second crystal grain, the first crystal grain and the second crystal grain have lithium, a transition metal, and oxygen, the grain boundary has magnesium and oxygen, and the positive electrode active material particle has a region in which the ratio of the atomic concentration of magnesium at the grain boundary to the atomic concentration of the transition metal in the first crystal grain and the second crystal grain is 0.010 or more and 0.50 or less.SELECTED DRAWING: Figure 1 【課題】劣化が少ない正極活物質粒子を提供する。または、劣化が少ない蓄電装置を提供する。または、安全性の高い蓄電装置を提供する。【解決手段】第１の結晶粒と、第２の結晶粒と、第１の結晶粒及び第２の結晶粒の間に位置する結晶粒界と、を有し、第１の結晶粒及び第２の結晶粒は、リチウムと、遷移金属と、酸素と、を有し、結晶粒界は、マグネシウムと、酸素と、を有し、第１の結晶粒及び第２の結晶粒における遷移金属の原子濃度に対する、結晶粒界におけるマグネシウムの原子濃度の比が、０．０１０以上０．５０以下の領域を有する正極活物質粒子である。【選択図】図１