High-power lithium ion battery for automobile start-stop power supply

Abstract

A high-power lithium ion battery for an automobile start-stop power supply comprises a positive plate and a negative plate, the tab width accounts for more than 50% of the width of the battery; the positive electrode current collector is a conductive coating aluminum foil with the total thickness of 24 microns, the conductive coating is coated on the positive electrode current collector before thepositive electrode active substance is coated, and the total thickness of the conductive coating is 0.5-2 microns; the positive electrode active substance is lithium iron phosphate; the positive electrode conductive agent is a mixture of carbon nanotubes, graphene and carbon black; and the electrolyte contains a lithium salt, an organic solvent and an additive. According to the invention, the overcurrent capacity of the battery can be improved, the power performance is enhanced, the problem of low conductivity of the lithium iron phosphate anode is solved, and the electrode conductivity is improved; particularly, the low-temperature rate discharge capacity is improved by more than 30%; the falling of lithium iron phosphate from the aluminum foil can be slowed down, and the cycle life is prolonged by about 8%; the electrolyte is not easy to vaporize at a high temperature, still has low viscosity at a low temperature of -30 DEG C, and maintains high ionic fluidity.

Description

technical field [0001] The invention belongs to the technical field of lithium ion batteries. In particular, the invention relates to a high-power lithium-ion battery used for a start-stop power supply of an automobile. Background technique [0002] The "Energy Conservation and New Energy Automobile Industry Development Plan" issued by the State Council in 2012 proposed that the average fuel consumption of passenger vehicles should drop to 6.9 liters / 100 kilometers by 2015 and 5 liters / 100 kilometers by 2020. The fuel consumption target of 5 liters per 100 kilometers in 2020 can only be achieved by applying 48V start-stop battery hybrid technology. At present, if the 48V start-stop battery hybrid technology is adopted in large quantities, it can achieve the effect of saving fuel by 10% to 20%, thereby reducing carbon emissions and achieving the effect of energy saving and emission reduction. [0003] The existing lithium-ion battery for starting and stopping has large inte...

AI Technical Summary

Problems solved by technology

[0003] The existing lithium-ion battery for starting and stopping has large internal resistance, low power, and low available energy. Especially at low temperatures, the battery cannot be charged with high power, which leads to the failure of the car to recover braking energy at low temperatures and reduces the fuel-saving effect.

In addition, the existing lithium-ion battery for start and stop has a short working life and rapid performance degradation at high temperatures

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