Lithium ion battery with high energy density

Abstract

The invention provides a lithium ion battery with high energy density, which is composed of a diaphragm, a negative electrode, a positive electrode and an electrolyte system. The negative electrode ismade of artificial graphite or artificial graphite mixed with modified natural graphite. The positive electrode side includes a positive electrode system active substance which is lithium cobalt oxide or a mixture of lithium cobalt oxide and a lithium nickel cobalt manganese oxide ternary material. The conductive agent used in the positive electrode system is single-walled carbon nanotubes or single-walled carbon nanotubes mixed with multi-walled carbon nanotubes. Based on the positive electrode slurry, the amount of conductive agent added in the positive electrode system is 0.04-0.06%. The solvent of the electrolyte system is the mixed solution of EC/DEC/EMC. The lithium salt in the electrolyte system is LiPF6. The lithium ion battery with high energy density has the advantage as follows: because an optimized positive electrode conductive agent and an optimized electrolyte system are adopted, the energy density of the lithium ion battery is increased, the energy density of the electrodes is increased by 1.5-4% compared with the normal system, the lithium ion battery has high specific energy and cycle performance, and the capacity retention rate is as high as 88% after 500 cyclesof 0.5C charging and 0.5C discharging.

Description

technical field [0001] The invention relates to the technical field of lithium-ion secondary battery chemical systems, in particular to a lithium-ion battery with high energy density. Background technique [0002] Lithium-ion batteries have the advantages of high theoretical specific capacity and energy density, long cycle life, no memory effect, and strong applicability. Since Sony's commercialization in 1991, it has received extensive attention and development. The rapid development of equipment such as notebook computers and mobile phones has rapidly become popular. As the design of modern electronic communication equipment develops in the direction characterized by "light, thin, short, and small", the demand for a small-volume, high-energy-density power lithium-ion battery system is increasingly urgent. [0003] The energy density of a lithium-ion battery depends on the gram capacity of the positive and negative active materials and the proportion of the active material...

AI Technical Summary

Problems solved by technology

But they all have a common defect, that is, they need to be added in a large proportion to meet the requirements of product application for electrode conductivity, which in turn reduces the proportion of active materials in electrodes and increases the energy density of electrodes and energy storage devices.

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