Lithium iron phosphate power lithium-ion battery

Abstract

The invention relates to the field of lithium ion batteries and discloses a lithium iron phosphate power lithium-ion battery. A positive electrode material is prepared from, by weight, 94-96 parts oflithium iron phosphate, 3-5 parts of a positive electrode conductive agent, 1-3 parts of a positive electrode adhesive and 10-20 parts of a dissolving agent. A negative electrode material is preparedfrom, by weight, 94-96 parts of a negative electrode granular material, 0.9-1.2 parts of a negative electrode conductive agent, 2-2.4 parts of a thickening agent and 2-2.4 parts of a negative electrode adhesive. The negative electrode granular material has a core-shell structure, artificial graphite serves as a core material, and amorphous carbon serves as a shell material. The positive electrodematerial and the negative electrode material are well matched, and the negative electrode material is low in granularity, high in uniformity and attachment on copper foils and low in contact internalresistance. After the positive electrode material and the negative electrode material are made into the lithium ion batteries, internal resistance of the batteries can be reduced while low-temperatureperformance, high-temperature performance and cycle performance of the batteries can be improved.

Description

technical field [0001] The invention relates to the field of lithium ion batteries, in particular to a lithium iron phosphate power lithium ion battery. Background technique [0002] With the gradual strengthening of energy and environmental awareness, new energy vehicles have made great progress in recent years. Among them, electric vehicles are one of the main directions. In the power battery of electric vehicles, lithium-ion batteries occupy a very important position. [0003] In lithium-ion power batteries, lithium iron phosphate is one of the choices of positive electrode active materials. [0004] For example, the Chinese invention patent with the application number CN201110299356.6 discloses a preparation process of a high-performance aqueous lithium iron phosphate power battery, which includes a positive electrode, a negative electrode, a diaphragm and a special power lithium iron phosphate electrolyte. Lithium iron phosphate is used as the positive electrode acti...

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Problems solved by technology

[0005] However, there are also certain defects in the lithium iron phosphate lithium ion power battery of the prior art. For example, the negative electrode material is generally selected as graphite, and the cooperation between the lithium iron phosphate positive electrode material and the negative electrode material is not ideal; The problem of poor adhesion and uniformity on the copper foil will lead to high internal resistance of the battery, poor low temperature performance, high temperature discharge performance, and poor cycle performance