W-containing high-nickel ternary positive electrode material and preparation method thereof

Abstract

The invention discloses a W-containing high-nickel ternary positive electrode material. The high-nickel ternary positive electrode material comprises spherical morphology secondary particles and monocrystalline morphology particles at the same time, the monocrystalline morphology particles basically do not contain W element, and the spherical morphology secondary particles are doped with W element; the preparation method comprises the following steps: mixing a nickel salt, a cobalt salt and a manganese salt according to a molar ratio, and adding ammonia water and a sodium hydroxide solution for coprecipitation to prepare a precursor A; mixing a nickel salt, a cobalt salt, a manganese salt and a tungsten salt, and preparing a precursor B containing a tungsten element through co-precipitation of ammonia water and a sodium hydroxide solution; and mixing the precursor A, the precursor B, a lithium source and a compound containing a doped element M, and carrying out high-temperature sintering in an aerobic atmosphere to obtain the high-nickel ternary positive electrode material simultaneously containing spherical secondary particles and single-crystal particles. The secondary sphericalparticles in a product can increase the capacity, and meanwhile, a crystal structure cannot generate obvious phase change during lithium ion deintercalation in the cycle process, so that the cycle performance is favorably improved.

Description

technical field [0001] The invention belongs to the technical field of lithium ion batteries, and in particular relates to a high-nickel ternary positive electrode material and a preparation method thereof. Background technique [0002] With the development of new energy vehicles today, the requirements for cruising range are constantly increasing. Therefore, for lithium battery cathode materials, the development of materials with higher nickel content is one of the research directions. The capacity advantage of high-nickel cathode materials is very obvious, and the actual gram capacity can reach about 200mAh / g. In addition, high-nickel materials have certain advantages in terms of price due to the lower use of Co. Although there is no large-scale application in the field of power battery energy storage due to constraints such as stability and cycle performance, with the continuous development of new doping coating technology and precursor technology, these disadvantages are...

AI Technical Summary

Problems solved by technology

[0004] At present, the materials of the above two morphologies have been used in combination (see the Chinese patent document of application number 201410050211.6), but it does not contain W element, and it usually uses physical blending, and the positive electrode materials of the two morphologies Direct mixing to obtain a high-nickel cathode material with both spherical morphology and single crystal morphology. Due to the different preparation processes of these two morphology materials, such as the preparation conditions of the two materials, sintering temperature, doping substances, coating substances, etc. are not the same, which leads to a large difference in the basic unit cell parameters of the two morphology materials. This difference requires the use of different battery systems to adjust the matching, so simple physical mixing has its significant disadvantages

Simple physical blending cannot effectively improve the capacity and cycle performance of materials; nor can it solve the disadvantages of gas production and rapid internal resistance growth; it cannot better match the battery system, but can simply increase its compaction density

Therefore, simple physical blending cannot substantially solve the problems existing in existing high-nickel materials, and may even be counterproductive.

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