Liquid flexible packaged lithium-ion cell and manufacture method thereof

Abstract

The invention discloses a liquid flexible packaged lithium-ion cell and a manufacture method thereof. The liquid flexible packaged lithium-ion cell comprises a positive electrode, a negative electrode, a diaphragm and an electrolyte, wherein an active medium of the positive electrode is lithium cobalt oxide LiCoO2, an active medium of the positive electrode is synthetic graphite, and the electrolyte is an electrolyte in which an impregnating compound, a stabilizing agent and a high-temperature additive are added. The manufacture method comprises the following steps of: preparing the positive electrode, namely, the lithium cobalt oxide, a conductive agent and a macromolecule binding agent form a mixture and then the mixture is uniformly coated on the surface of a metal aluminum foil; preparing the negative electrode, namely, the synthetic graphite, the conductive agent and the binding agent form a mixture, and the mixture is uniformly coated on the surface of a metal copper foil; and preparing the electrolyte, namely, the impregnating agent, the stabilizing agent and the high-temperature additive are blended into the electrolyte. According to the manufacture method, the volumetric specific energy of the lithium-ion cell can be remarkably improved, and the final battery cell is good in electrochemical performance.

Description

technical field [0001] The invention belongs to the manufacturing process of lithium-ion secondary batteries suitable for liquid soft packaging, and aims at high volume ratio energy liquid soft packaging batteries. Background technique [0002] With the improvement of people's quality of life, electronic products have higher and higher requirements on the volume ratio and energy of power supplies. Manufacturers such as smartphones and tablet computers have higher capacity requirements for battery providers. [0003] At present, the material system commonly used by secondary cell manufacturers to produce high volume ratio energy cells using liquid flexible packaging is high-pressure compacted positive electrode material + high-pressure compacted negative electrode material + separator + LiPF6 electrolyte, and the high-pressure compacted positive electrode material is mainly cobalt lithium cobaltate or lithium cobaltate doped with binary nickel-cobaltate lithium, the high-pres...

AI Technical Summary

Problems solved by technology

[0004] Using the current material system can only ensure that the battery cell has a higher capacity, but because the material system uses a thinner separator, the short circuit rate of the process is relatively high, and the separator has poor liquid absorption and liquid retention performance, so the pass rate of the process is low. Due to the use of high-pressure negative electrode materials, the permeability of the electrolyte becomes poor, and the electrochemical performance of the battery cell is defective, especially the cycle and safety performance is very poor, that is, the electrochemical performance of this high-capacity battery cell is unqualified and cannot meet the national standard. and industry performance parameter standards

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