High-capacity cylindrical 18650 lithium-ion battery and preparation method thereof

Abstract

The invention discloses a high-capacity cylindrical 18650 lithium-ion battery. Nickel-cobalt lithium aluminate is adopted as a positive active material; SuperP is adopted as a conductive agent; polyvinylidene fluoride (PVDF) is adopted as an adhesive; an aluminum foil is adopted as a positive current collector; graphite is adopted as a negative active material; the SuperP is adopted as the conductive agent; carboxyl methyl cellulose (CMC) is adopted as a thickening agent; butadiene styrene rubber (SBR) is adopted as the adhesive; and a copper foil is adopted as a negative current collector. The used positive material nickel-cobalt lithium aluminate has the advantages of high specific capacity, low cost, abundant raw material resource, good safety, environmental friendliness and the like; the used negative material graphite has the characteristics of high specific capacity, good cycle performance, low cost and the like; the high-capacity cylindrical 18650 lithium-ion battery prepared from the nickel-cobalt lithium aluminate and the graphite has the advantages that the capacity reaches 3100mAh; the cycle performance is good; and the capacity retention ratio is greater than 80% after 300 cycles at 0.5 C / 0.5C.

Description

technical field [0001] The invention relates to a high-capacity cylindrical 18650 lithium-ion battery and a preparation method thereof, in particular to a preparation method and electrochemical performance of a nickel-cobalt lithium aluminate-graphite lithium-ion battery. Background technique [0002] Lithium-ion batteries have been widely used in various electronic fields due to their high voltage, high capacity, good safety, and environmental friendliness. There are many types of lithium-ion batteries, including square batteries, aluminum shell batteries, pouch batteries, and cylindrical batteries, some of which focus on capacity, and some that focus on rate. Among them, the capacity-type 18650 cylindrical battery is widely used in mobile power supplies, notebook computers, electric bicycles, electric vehicles and other fields due to its fixed size and high capacity. At present, the capacity type cylindrical batteries on the market are mainly 2000mAh, 2200mAh and other ca...

AI Technical Summary

Problems solved by technology

Traditional lithium-ion batteries using lithium cobalt oxide, lithium manganese oxide, lithium iron phosphate, and lithium nickel manganese cobalt oxide as cathode materials have been difficult to meet the requirements of high energy density.

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