Novel double-doped mixed cobalt-free system positive plate and lithium ion battery

Abstract

The invention belongs to the technical field of lithium ion batteries, and particularly relates to a novel double-doped mixed cobalt-free system positive plate and a lithium ion battery comprising the positive plate. The positive plate comprises a positive current collector and a positive coating coated on the positive current collector, the positive coating comprises a positive active material, and the positive active material is a mixture composed of lithium manganate, lithium iron manganese phosphate and a lithium-rich manganese-based positive material. According to the present invention, the lithium manganese iron phosphate, the lithium manganate and the lithium-rich manganese-based positive electrode material are mixed and matched for use, the lithium manganate is low in cost and high in safety, the lithium manganese iron phosphate provides high capacity and long cycle, and the lithium-rich manganese-based positive electrode material improves the high-temperature performance and high-temperature cycle performance of the lithium manganate. The energy density, the high temperature, the cycle performance and the safety performance of a battery using the positive plate are obviously superior to those of a battery made of a pure lithium manganate material, and the manufacturing cost of the battery is also obviously reduced as no ternary material is arranged in the positive plate.

Description

Technical field [0001] The present invention belongs to the technical field of lithium ion battery, and more particularly to a novel double doped mixed-free cobalt-cobalt positive electrode sheet, a lithium ion battery. Background technique [0002] Electric vehicles, electric bicycles and electric tools, etc. have increased year by year. In the near future, the production of lithium-ion batteries will be ushered in the explosive growth of a period of time. [0003] The current lithium ion battery positive material is lithium cobaltate, lithium manganese acid, lithium iron phosphate, three-dimensional material, etc. wherein the lithium cobalt energy is high, high compact density, but the cycle performance is general, and the price of cobalt, price Expensive; lithium manganate is cheap, rich in manganese resources, good safety, but the volume is low, and the cycle performance, high temperature performance; lithium iron phosphate is safe, the cycle performance is good, the price is...

AI Technical Summary

Problems solved by technology

[0003] Existing cathode materials for lithium-ion batteries include lithium cobaltate, lithium manganate, lithium iron phosphate, ternary materials, etc. Among them, lithium cobaltate has high energy density and high compaction density, but its cycle performance is average and it contains the scarce element cobalt. Expensive; lithium manganese oxide has the characteristics of cheap price, rich manganese resources, and good safety, but its gram capacity is low, and its cycle performance and high temperature performance are poor; lithium iron phosphate has the advantages of safety, good cycle performance, and low price, but its pressure Low solid density, poor electronic conductivity, and low voltage platform, only 3.2V, it is difficult to mix and match with materials such as lithium manganese oxide or nickel-cobalt lithium manganese oxide; nickel-cobalt lithium manganese oxide material has high gram capacity and good cycle performance, etc. Advantages, but also contain cobalt, and the safety is very poor

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