Preparation method of lithium ion battery and lithium ion battery

Abstract

The invention discloses a preparation method of a lithium ion battery and the lithium ion battery and relates to the technical filed of lithium ion batteries. The preparation method of the lithium ionbattery comprises the following steps: pre-treatment of positive and negative current collectors, preparation of positive and negative pole pieces and assembly of batteries; the positive and negativecurrent collectors are wiped with an oxalic acid solution firstly and are then wiped with a potassium permanganate solution; the positive pole piece is coated with graphene-cyclodextrin cross-linkedpolymer slurry firstly and is then coated with positive material slurry, the coating surface density is 75-85 mg / cm<2>, and a positive active material occupies 98-99 percent of a positive material andcomprises 10-30 percent of lithium cobaltate, 10-30 percent of lithium nickelate, 50-70 percent of LiMnxFe(1-x)PO4 (x is more than 0.5 but less than 1). The preparation method of the lithium ion battery and the lithium ion battery, disclosed by the invention, have the benefits that the problem that the current battery energy density and the safety cannot be considered is solved; the lithium ion battery obtained by the preparation method disclosed by the invention not only is high in energy density, but also is good in safety.

Description

technical field [0001] The invention relates to the technical field of lithium-ion batteries, in particular to a preparation method of a lithium-ion battery and the lithium-ion battery. Background technique [0002] Lithium-ion batteries have the advantages of high specific energy, high working voltage, and long cycle life, and have been developed rapidly since their commercialization. With the application of lithium-ion batteries in hybrid electric vehicles and electric vehicles, the demand for lithium-ion batteries with high energy density (the ratio of battery energy and battery weight / volume) is increasing. [0003] The energy density of lithium-ion batteries is closely related to the selection of positive and negative active materials and the entire preparation process. The existing active materials for lithium-ion battery positive materials include lithium iron phosphate, lithium manganese oxide, and nickel-cobalt lithium manganese oxide. Among them, although the lith...

AI Technical Summary

Problems solved by technology

Among them, although the lithium iron phosphate / graphite system battery has good safety, its energy density is only about 120Wh / kg; although the lithium manganese oxide / graphite system battery has good safety, it has low energy density and poor high-temperature performance; Although lithium cobalt manganese oxide / graphite system battery has high energy density, its safety is poor

Positive and negative electrode materials often have poor bonding force in the process of bonding with the current collector, which seriously affects the electrochemical performance of the battery.

[0004] The current lithium-ion batteries still have defects in energy density and safety performance, how to obtain lithium-ion batteries with high energy density and high safety has become an urgent problem to be solved

Images