Lithium iron phosphate positive plate and environment-friendly low-temperature-resistant lithium battery comprising same

Abstract

The invention discloses a lithium iron phosphate positive plate. The lithium iron phosphate positive plate comprises an aluminum foil and water-based positive slurry which coats the aluminum foil; thewater-based positive slurry comprises lithium iron phosphate, carbon nanotubes, graphene, chitosan, butadiene styrene rubber, sodium carboxymethyl cellulose, sodium alginate and amino silicone oil; and the particle size of the lithium iron phosphate is 4-10 microns. According to the lithium iron phosphate positive plate of the invention, a positive electrode active substance with large particle size and small specific surface area is adopted, so that the low-temperature performance of the lithium iron phosphate positive plate is good; the environment-friendly water-based positive electrode slurry is adopted, so that the positive electrode plate is environment-friendly, non-toxic, good in processing environment adaptability and stable in processing performance, and the obtained positive electrode plate is high in compaction density, high in specific energy and excellent in low-temperature property. The invention further discloses an environment-friendly low-temperature-resistant lithium battery which comprises the lithium iron phosphate positive plate and is combined with a negative plate with high cost performance, large capacity and high activity, and the obtained lithium iron phosphate battery is good in safety performance, high in energy density, excellent in low-temperature performance, stable in processing performance, free of pollution in the production process and low in battery cost.

Description

Technical field [0001] The present invention relates to the technical field of lithium batteries, in particular to a lithium iron phosphate positive electrode sheet and an environmentally friendly low-temperature resistant lithium battery containing the positive electrode sheet. Background technique [0002] With the development of mobile electronic devices, the demand for batteries is increasing, and higher requirements are put forward for the capacity, voltage, service life and use cost of the batteries. Lithium-ion battery is a kind of secondary battery (rechargeable battery). It mainly relies on the movement of lithium ions between the positive and negative electrodes to work. However, the lithium-ion batteries on the market often have poor safety performance and poor low-temperature performance. There are many shortcomings of low capacity, low capacity per unit volume, low power, and poor cycle performance. Among them, the lithium iron phosphate lithium ion battery is a lit...

AI Technical Summary

Problems solved by technology

[0003] However, there are some performance defects in existing iron-lithium lithium-ion batteries, such as very low tap density and compaction density, resulting in low energy density of lithium-ion batteries; poor low-temperature performance, which cannot Make electric vehicles drive; unstable processing performance: The production and processing of lithium iron phosphate requires high humidity in the production environment, and the slurry is prone to thickening after water absorption, resulting in unstable coating surface density, which leads to more problems. For example, the qualified rate of the produced products is lower than 90%, the product consistency is poor, the proportion of safety hazards is high, the cycle performance of 0.5C / 1C is less than 1000 cycles, the weight specific energy is low, and the volume power density is low.

The above problems seriously limit the wide application of lithium iron phosphate batteries in new energy vehicles and other fields

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