A lithium battery pack for new energy vehicles

Abstract

The invention relates to the technical field of new energy automobiles, and discloses a lithium battery pack for new energy automobiles, which includes a single battery, and heating plates are fixedly installed on both sides and bottom of the single battery, and the heating plate is close to the single battery. The negative electrode of the body battery is electrically connected to a temperature control switch, the heating plate and the temperature control switch are connected in series and electrically connected to the negative electrode of the single battery, and an electric box is fixedly installed on the back of the single battery. The lithium battery pack for new energy vehicles, through the large internal resistance of the battery under low temperature conditions and the resistance of the heating plate is smaller than the battery resistance, so that the current passes through the heating plate and can automatically break the circuit after reaching the specified temperature, so that when the temperature is low In the process of slow charging, first increase the temperature of the heating plate to heat the single battery, improve the fluidity of the electrolyte inside the single battery, enhance the ion mobility under low temperature conditions, improve the charging efficiency of the single battery, and make the single battery The battery acquires the capacity at the appropriate temperature.

Description

technical field [0001] The invention relates to the technical field of new energy vehicles, in particular to a lithium battery pack for new energy vehicles. Background technique [0002] Pure electric vehicles have become one of the important development directions of new energy vehicles because they can truly achieve "zero emissions". Lithium-ion batteries have become the ideal power for pure electric vehicles due to their high energy density and high voltage platform. Lithium-ion batteries are generally Using lithium alloy metal oxide as the positive electrode material, graphite as the negative electrode material, and a battery using a non-aqueous electrolyte, the battery is charged and discharged through the movement of lithium ions on the positive and negative electrodes, while the pure electric vehicle battery pack uses multiple single cells formed in series. [0003] However, lithium-ion batteries still have the following defects in the charging process: [0004] Fir...

AI Technical Summary

Problems solved by technology

[0004] First of all, in the lithium ion production process, a high melting point solvent is added to the battery electrolyte to make the battery have better stability when used at high temperature, but because the high melting point solvent is mixed in the electrolyte, the lithium ion battery electrolyte Viscosity increases in low temperature environment. When the temperature is too low, the electrolyte will solidify, resulting in a decrease in the transmission rate of ions in the electrolyte, which will reduce the capacitance when using a pure electric vehicle at low temperature, and greatly reduce the driving distance.

[0005] Secondly, due to the difference in the external environment during the production, transportation and use of lithium-ion batteries, the capacity of each single battery will be different, while the pure electric vehicle battery pack is charged and discharged after connecting multiple single batteries in series. , the battery with the smallest capacity of a single cell determines the capacity of the entire battery pack, and the capacity attenuation of some single cells will affect the service life of the entire battery pack

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