Lithium ion battery and preparation method thereof

Abstract

The invention discloses a lithium ion battery and a preparation method thereof. The lithium ion battery comprises cathode slurry and anode slurry, wherein the solid content of the cathode slurry is 50.0%-60.0% and the viscosity number is 6000-8000 cp; the solid content of the anode slurry is 40.0%-50.0% and the viscosity number is 3000-5000 cp. The invention further comprises the preparation method. After circulation for 1500 times, the capacity retention ratio of a lithium iron phosphate system lithium ion battery with high magnification, high energy density and long service life is higher than 80.0% and the energy density is greater than 175 Wh / Kg under the high-rate charge-discharge system of 10-20 C; the preparation method has the advantages of simple selected material system, strong controllability of the preparation process, good product consistency and high section first pass yield; the processing first pass yield of a lithium ion battery with the rated capacity of 10 AH reaches up to 87.5%, and the product percent of pass is high and reaches up to 95.3%.

Description

technical field [0001] The invention belongs to the technical field of lithium ion batteries, and in particular relates to a lithium ion battery and a preparation method thereof. Background technique [0002] From the perspective of the whole world, after the end of the Copenhagen era, low-carbon, emission reduction, and energy-saving have become the core competitiveness of automobile technology. Countries around the world have burst out huge research and development energy in new energy, especially new energy vehicles. New energy vehicles During the period of rapid development of the industry (including buses, logistics vehicles, office vehicles for enterprises and institutions, and private cars), the lithium-ion battery is faced with problems such as high rate, high energy density and long life at the same time, so that the development of new energy vehicles and promotion are limited by bottlenecks. [0003] At present, lithium-ion batteries suitable for new energy vehicl...

AI Technical Summary

Problems solved by technology

However, each lithium-ion battery system itself has some serious defects, such as poor cycle performance and high-temperature performance of lithium manganate system; poor safety of ternary material system; relatively small energy density of lithium iron phosphate system, lithium iron phosphate The lithium-ion battery of the system is charged and discharged at a high rate of more than 3C. After 1000 cycles, the capacity retention rate is less than 80.0%, and the energy density is less than 130Wh / Kg. Compared with the performance of lithium-ion batteries of various systems, iron phosphate with olivine structure The lithium-ion battery of the lithium system has the most potential in the field of new energy vehicles

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