Method for controlling crystal growth in preparation process of lithium battery positive electrode ternary precursor

• Main Authors: SONG FANGHENG, WANG CHENGQIAO, XING WANGYAN, LYU DONGLIANG, WANG ZHENGQIANG, ZUO MEIHUA, YANG RUI, SUN HONG, JIANG XUEPING, DU XIANFENG
• Format: Patent
• Language: Chinese; English
• Published: 06.06.2023
• Subjects: AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUSPOLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR; BASIC ELECTRIC ELEMENTS; CHEMISTRY; CRYSTAL GROWTH; ELECTRICITY; METALLURGY; PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSIONOF CHEMICAL INTO ELECTRICAL ENERGY; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITHDEFINED STRUCTURE; REFINING BY ZONE-MELTING OF MATERIAL; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITHDEFINED STRUCTURE; SINGLE-CRYSTAL-GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL ORUNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL

The invention discloses a method for controlling crystal growth in a lithium battery positive electrode ternary precursor preparation process in an oxygenation mode, which comprises the following steps: in a synthesis reaction stage, when the reaction granularity reaches 2.0-2.5 mu m, adjusting the nitrogen flow, the air flow above the liquid level and the air flow below the liquid level, keeping the oxygen content above the liquid level to be 10000-50000 ppm, keeping the oxygen content of a thickener clear liquid to be 1000-15000 ppm, and keeping the oxygen content of the thickener clear liquid to be 1000-15000 ppm; and then continuously reacting until the particle size reaches the target particle size of 3.3-4.0 microns. According to the invention, a certain amount of antioxidant hydrazine hydrate is added into the kettle starting bottom water at the early stage of the synthetic reaction, and the precursor particles with slender primary particles, relatively uniform pore distribution and uniform size can be