Lithium manganate material for surface treatment and preparation method thereof

Abstract

The invention discloses a lithium manganate material for surface treatment and a preparation method thereof. The lithium manganate material for surface treatment takes doped and modified lithium manganate as a basal body, the basal body is coated by a surface treatment material to form a surface coating layer which is a product of the surface treatment material, a product obtained by partially decomposing the surface treatment material, or a product obtained by completely decomposing the surface treatment material, and the concentration of the surface coating layer is in graded distribution namely gradually reducing from outside to inside; and the general formula of the basal body is LixMn2-yMyO4-zXz, wherein x is more than or equal to 0.95 and less than or equal to 1.15, y is more than or equal to 0 and less than or equal to 0.2, z is more than or equal to 0 and less than or equal to 0.4, M is one or more of Li, Cr, Co, Ni, Mg, Ca, Sr, Ba, Na, K, Al, Be, B, Ti, Zr, Cu, Zn, Ga, Sn or V, the doping element X is one or more of F, Cl, Br, I or S, and the surface treatment material is one or more of organic substances containing Ti and / or Al. Through the surface treatment on the doped and modified lithium manganate, the compatibility of the lithium manganate material with an electrolyte is increased, less Mn is dissolved out in the electrolyte, the high-temperature storage performance and high-temperature cycle performance of the lithium manganate material are improved, and the bulk phase stability and the surface stability of the material are improved at the same time.

Description

technical field [0001] The invention relates to a lithium manganate material for a lithium ion battery and a preparation method thereof, in particular to a surface-treated lithium manganate material for a lithium ion battery and a preparation method thereof. Background technique [0002] At present, lithium-ion batteries have been widely used in mobile phones, notebook computers, digital products and other fields. With the increasingly serious energy crisis, the application of lithium-ion batteries in new energy vehicles has become a hot research field. The positive electrode material used in traditional lithium-ion batteries is lithium cobalt oxide. Due to the high price of cobalt and the poor safety of lithium cobalt oxide materials, it is difficult to be used as electric vehicle batteries. [0003] Spinel-type lithium manganese oxide has become one of the most promising positive electrode substitute materials for its rich raw material resources, low price, good safety, no...

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Problems solved by technology

In the patent application CN101038965A, at least one of a layer of boron-lithium composite oxide, cobalt-lithium composite oxide, vanadium-lithium composite oxide or carbon layer is coated on the basis of doped lithium manganate, so that the normal temperature of the lithium manganate material The cycle and high temperature cycle have been improved to a certain extent; however, since the coating is an oxide, it is easy to cause uneven dispersion of the coating or the inability to form a concentration gradient of the coating elements in the actual production process, thus failing to achieve the desired coating effect

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