Prismatic lithium ion battery for hybrid electric vehicle startup power supply and manufacturing method thereof

Abstract

The invention relates to the technical field of manufacturing of lithium ion secondary batteries and provides a prismatic lithium ion battery for a hybrid electric vehicle startup power supply and a manufacturing method thereof. The battery comprises a positive plate, a negative plate, a diaphragm, an electrolyte, an insulating bushing and a battery case, wherein the positive plate contains a positive active material, a binding agent, a conductive agent, an aluminum foil and the like; the negative plate comprises a negative active material, a binding agent, a conductive agent, an aluminum foil and the like. A material system is optimized, the positive active material is lithium iron phosphate coated with a composite containing Al2O3-loaded N grapheme; the negative active material is natural graphite coated with a composite containing CuO / Cu-loaded multi-walled carbon nanotubes. The lithium ion battery manufactured under optimum conditions is low in internal resistance, is excellent in multiplying power cycling performance and heavy load discharge performance, and can meet hybrid electric vehicle startup power supply requirements.

Description

technical field [0001] The invention belongs to the technical field of lithium-ion battery production, and relates to a square lithium-ion battery for a starting power supply of a hybrid electric vehicle and a manufacturing method thereof. The battery includes a positive electrode sheet, a negative electrode sheet, a diaphragm, an electrolyte, an insulating bushing and a battery casing, the positive electrode sheet contains a positive electrode active material, a binder, a conductive agent and aluminum foil, and the negative electrode sheet contains a negative electrode active material, a binder, and a conductive agent. and copper foil, the diaphragm is PP / PE / PP three-layer film, the electrolyte is a high-conductivity safe electrolyte, the insulating bushing is polypropylene film, and the battery shell is made of aluminum alloy, which is formed by laser welding. The invention optimizes the material system, including the optimization of the positive active material, which is a ...

AI Technical Summary

Problems solved by technology

[0003] 1. Some lithium-ion batteries have the problem of large internal resistance, and the internal resistance of lithium-ion batteries has a great impact on battery performance. The internal resistance of the battery is large, which will generate a lot of Joule heat, resulting in a decrease in the battery discharge operating voltage and a short discharge time. shortened, affecting battery life

[0004] 2. In the field of hybrid electric vehicles, the adapted battery needs to have instantaneous high power, which has high requirements on the high-current discharge performance of the battery. However, when the lithium-ion battery is discharged at a high current, the battery heats up rapidly and even short-circuits , there is a serious security risk

[0005] 3. The rate cycle performance of ordinary lithium-ion batteries is poor. Under rate cycle conditions, the internal polarization of the battery increases, and the internal resistance increases. capacity and life

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