A lithium ion battery

Abstract

The invention is applicable to the field of lithium ion batteries, and provides a lithium ion battery comprising a cathode plate, an anode plate, a membrane and electrolyte, wherein the surface of the cathode plate is coated with cathode slurry including cathode active materials including lithium iron phosphate, ternary material and lithium manganese ferric phosphate; the ternary material is represented by the formula of LiNixCOyMn1-x-yO2, wherein x is less than 1 and more than 0, y is less than 1 and more than 0, and the sum of x and y is less than 1 and more than 0. The mass ratio of the lithium iron phosphate, ternary material and lithium manganese ferric phosphate is (10-60):(10-50):(10-50). The cathode slurry also includes conductive agents which are carbon nanotubes. The lithium ion battery provided by the invention is significantly improved in cycle performance, energy density and safety performance.

Description

technical field [0001] The invention belongs to the field of lithium ion batteries, and in particular relates to a lithium ion battery. Background technique [0002] With the continuous consumption and depletion of traditional fossil fuel energy, countries all over the world are trying their best to find new alternative energy sources. Lithium-ion batteries have become a research hotspot because of their advantages such as long cycle life, high energy density, no memory effect, and environmental protection. . In recent years, with the promotion and support of new energy industries around the world, new energy vehicles have ushered in a period of rapid development, and lithium-ion batteries have become an important energy supply for new energy batteries. [0003] At present, lithium-ion batteries used in the field of new energy vehicles mainly include lithium iron phosphate batteries, ternary batteries and lithium manganese iron phosphate batteries. Lithium iron phosphate h...

AI Technical Summary

Problems solved by technology

However, the tap density and compaction density of lithium iron phosphate are low, and the discharge voltage platform is low (about 3.2V), which makes the energy density of lithium iron phosphate battery low. At present, the highest energy density of cylindrical 32650 type lithium iron phosphate battery is about 120Wh / Kg, which is difficult to meet the increasingly stringent requirements of new energy vehicles for cruising range

The advantage of ternary batteries applied to new energy vehicles lies in their high energy density (≥150Wh / Kg), but their safety performance is poor, and it is difficult to pass the acupuncture test, which requires a relatively complete battery management system to control

The advantages of lithium manganese iron phosphate batteries are good safety and high working voltage, but the rate performance and cycle performance of lithium manganese iron phosphate are poor

Therefore, there is still a lack of a lithium-ion battery with high safety performance, long cycle performance and high energy density in the art.

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