POSITIVE ELECTRODE ACTIVE MATERIAL, MANUFACTURING METHOD THEREFOR, AND POSITIVE ELECTRODE AND LITHIUM SECONDARY BATTERY COMPRISING SAME

• Main Authors: KIM, Ji Hye, PARK, Byung Chun, JUNG, Hae Jung, HEO, Jong Wook, JO, Chi Ho
• Format: Patent
• Language: English; French; Korean
• Published: 27.06.2024
• Subjects: BASIC ELECTRIC ELEMENTS; CHEMISTRY; COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSESC01D OR C01F; ELECTRICITY; INORGANIC CHEMISTRY; METALLURGY; PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSIONOF CHEMICAL INTO ELECTRICAL ENERGY

The present invention relates to a positive electrode active material and a manufacturing method therefor, the positive electrode active material comprising: a lithium composite transition metal oxide which is in the form of a secondary particle in which a plurality of grains are aggregated, and includes an oriented structure in which the long axis of the grains is arranged in a direction from the center of the secondary particle to the surface thereof in at least a portion of the secondary particle; and a coating layer formed on the surface of the secondary particle and comprising a Co element, wherein the lithium composite transition metal oxide contains nickel and cobalt, and satisfies C1 < C2 < C3, when the ratio of the mole number of cobalt to the mole number of nickel inside the grains is C1, the ratio of the mole number of cobalt to the mole number of nickel at the grain boundary, which is the interface between the grains, is C2, and the ratio of the mole number of cobalt to the mole number of nickel in the coating layer is C3. La présente invention concerne un matériau actif d'électrode positive et son procédé de fabrication, le matériau actif d'électrode positive comprenant : un oxyde de métal de transition composite de lithium qui se présente sous la forme d'une particule secondaire dans laquelle une pluralité de grains sont agrégés, et qui comprend une structure orientée dans laquelle l'axe long des grains est disposé dans une direction allant du centre de la particule secondaire à la surface de celle-ci dans au moins une partie de la particule secondaire ; et une couche de revêtement formée sur la surface de la particule secondaire et comprenant un élément Co, l'oxyde de métal de transition composite de lithium contenant du nickel et du cobalt, et satisfaisant à C1 < C2 < C3, lorsque le rapport du nombre molaire de cobalt au nombre molaire de nickel à l'intérieur des grains est C1, le rapport du nombre molaire de cobalt au nombre molaire de nickel à la limite des grains, qui est l'interface entre les grains, est C2, et le rapport du nombre molaire de cobalt au nombre molaire de nickel dans la couche de revêtement est C3. 본 발명은, 복수의 그레인(grain)들이 응집된 2차 입자 형태이고, 상기 2차 입자의 적어도 일 부분에서 상기 그레인의 장축이 2차 입자의 중심에서 표면 방향으로 배열된 배향성 구조를 포함하는 리튬 복합 전이금속 산화물; 및 상기 2차 입자의 표면에 형성되고, Co 원소를 포함하는 코팅층을 포함하고, 상기 리튬 복합 전이금속 산화물이 니켈 및 코발트를 포함하고, 상기 그레인 내부에서의 니켈 몰수에 대한 코발트의 몰수 비를 C1, 상기 그레인들간의 경계면인 입계(Grain boundary)에서의 니켈 몰수에 대한 코발트의 몰수 비를 C2, 상기 코팅층에서의 니켈 몰수에 대한 코발트의 몰수 비를 C3라 할 때, C1 < C2 < C3을 만족하는 양극 활물질 및 그 제조 방법에 관한 것이다.