Lithium ion battery for automotive startup power supply

Abstract

The invention provides a lithium ion battery for an automotive startup power supply. The lithium ion battery contains a cathode material, an anode material, a diaphragm and an electrolyte. The cathode material contains, by weight, 45-53% of lithium iron phosphate, 1-2% of conductive graphite, 1-2% of conductive carbon nanotube, 3-4% of polyvinylidene fluoride and the balance N-methylpyrrolidone. Material system optimization includes cathode material optimization by using a nanoscale lithium iron phosphate material, anode material optimization by using the anode material with large interplanar spacing, and selection of a diaphragm material with high porosity and an optimized electrolyte. Thus, discharge termination voltage of the lithium ion battery for the automotive startup power supply is greater than 2.2V at minus 18 DEGC / 30C, 1C / 30C discharge circulation reaches 2000 times at 60 DEG C, and capacity retention rate is greater than 90%. Rate capability of the battery is good, and low-temperature low-rate discharge termination voltage is high. Thus, the battery can meet requirements of the automotive low-temperature startup power supply, and cycle life and safety performance of the battery can be guaranteed.

Description

technical field [0001] The invention belongs to the technical field of lithium-ion battery production, and in particular relates to a lithium-ion battery for an automobile starting power supply. Background technique [0002] Lead-acid batteries have always dominated the automotive starter power market. As environmental problems become more and more prominent, lead-acid batteries will gradually be replaced by new clean energy sources. As a new energy source with high specific energy, long cycle life and low environmental pollution, lithium-ion batteries have gradually replaced lead-acid batteries in some application fields, but the low-temperature discharge performance of lithium-ion batteries, especially the high-rate discharge performance at low temperatures, is inferior Poor, it can't meet the needs of starting the car at low temperature, and the high-temperature cycle performance of the lithium-ion battery is not enough to meet the needs of the environment where the car's...

AI Technical Summary

Problems solved by technology

As a new energy source with high specific energy, long cycle life and low environmental pollution, lithium-ion batteries have gradually replaced lead-acid batteries in some application fields, but the low-temperature discharge performance of lithium-ion batteries, especially the high-rate discharge performance at low temperatures, is inferior Poor, it can not meet the needs of starting the car at low temperature, and the high-temperature cycle performance of the lithium-ion battery is not enough to meet the needs of the environment in which the car starts the power supply

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