High-safety lithium manganese iron phosphate battery

Abstract

The invention belongs to the technical field of lithium ion batteries and specifically relates to a high-safety lithium manganese iron phosphate battery. The high-safety lithium manganese iron phosphate battery comprises a positive plate, a negative plate, an isolating membrane, an electrolyte and a battery shell, wherein the positive plate includes a positive pole current collector and a positive pole active material layer which is coated on a surface of the positive pole current collector; the positive pole active material layer includes the following components by weight percentage: 90wt%-96wt% of positive pole active material, 1.5wt%-5wt% of positive pole conductive agent and 2wt%-5wt% of positive pole binding agent; the positive pole conductive agent is a mixture of conductive carbon black and at least one of a carbon nano tube or graphene; and the ratio of the conductive carbon black to at least another conductive agent is 1wt%:0.5wt% to 4wt%:1wt% based on the weight percentage in the positive pole active material layer; the isolating membrane is one of a polyolefin film or a non-woven cloth film; and the electrolyte is a high-temperature-resistant electrolyte. Compared with a nickel cobalt lithium manganate ternary battery and a lithium iron phosphate battery, the high-safety lithium manganese iron phosphate battery has relatively high weight specific energy and relatively high safety performance at the same time, has a long cycle life and is suitable for popularization and application in the field of new energy vehicles.

Description

Technical field [0001] The invention belongs to the technical field of lithium ion batteries, and specifically relates to a highly safe lithium iron manganese phosphate battery. Background technique [0002] Since 2015, my country's automotive power lithium-ion battery market has experienced explosive growth. At the same time, the application market has increasingly stringent performance requirements for lithium-ion batteries, especially the new national standard for power batteries for electric vehicles released in May 2015, which puts forward higher requirements for battery safety. [0003] Safety and energy density, as key indicators of power lithium-ion batteries, have always been the focus of research and solutions in the industry. At present, the most widely used power lithium-ion battery systems at home and abroad are mainly lithium iron phosphate series and ternary (nickel manganese cobalt or nickel cobalt aluminum three metal elements) series. However, both systems...

AI Technical Summary

Problems solved by technology

At present, the most widely used power lithium-ion battery systems at home and abroad are mainly lithium iron phosphate system and ternary (nickel-manganese-cobalt or nickel-cobalt-aluminum three metal elements) system, but these two systems have obvious advantages and disadvantages, and cannot be completely Meet the needs of the development of power lithium-ion batteries

Lithium iron phosphate battery has excellent cycle life and safety performance, but the specific energy is difficult to exceed 1401,4-butane sultone / Kg

The specific energy of the ternary system battery can reach more than 1801,4-butane sultone / Kg, but while maintaining high specific energy, the cycle life will be significantly worse than that of the lithium iron phosphate system battery, and there are big problems in safety performance

If a battery with high safety, long life and ternary high specific energy characteristics of lithium iron phosphate can be developed, it will have a huge impact on the development of power batteries

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