Preparation method of 18650 cylindrical lithium ion battery with capacity up to 3400 mAh

Abstract

The invention provides a preparation method of a 18650 cylindrical lithium ion battery with a capacity up to 3400 mAh. The positive and negative active materials used are a nickel cobalt cobalt aluminate positive electrode and a silicon carbon negative electrode respectively. The materials used for the positive electrode slurry are: nickel cobalt aluminum aluminate, conductive carbon nanotubes, polyvinylidene fluoride and N-methyl pyrrolidone. Materials used for the negative electrode slurry include: silicon carbon composite materials, conductive carbon black, sodium carboxymethyl cellulose, styrene-butadiene rubber emulsion, deionized water, and N-methylpyrrolidone. The positive and negative ingredients are processed in a new batching process to shorten the batching time by 1 to 3 hours.The cap uses a dynamic explosion-proof cap with CID to effectively protect the battery safety performance; the diaphragm is made of high-strength wet-stretched diaphragm with safety performances effectively protecting the battery such as high mechanical strength, good heat resistance and good permeability. The 18650 cylindrical lithium ion battery is high in capacity (up to 3400mAh), high in specific energy (up to 270 Wh/kg), excellent in cycle performance, excellent in rate performance and excellent in high and low temperature performance.

Description

technical field [0001] The invention relates to the field of new energy, in particular to a high-capacity cylindrical lithium-ion battery and a manufacturing process thereof. Background technique [0002] With the continuous development of the new energy field, especially the lithium battery field, the energy density requirements for lithium-ion batteries are getting higher and higher. 18650 cylindrical battery is widely used because of its fixed size and relatively simple production process. Conventional 18650 cylindrical lithium-ion batteries with a capacity of about 2000 mAh have an energy density of about 170 Wh / kg, which is difficult to meet the needs of high energy density batteries in specific fields. In addition, in the production process of lithium batteries, the wet-mixing process generally uses glue first, and then adds conductive agents, active substances, etc. in sequence. Except for the glue-making time, the batching time is 6-8 hours. In view of this, the pr...

AI Technical Summary

Problems solved by technology

The conventional 18650 cylindrical lithium-ion battery with a capacity of about 2000mAh has an energy density of about 170Wh / kg, which is difficult to meet the demand for high energy density batteries in specific fields

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