Power battery equalization and heating composite circuit based on LC resonance and conductive film

Abstract

The invention relates to a power battery equalization and heating composite circuit based on LC resonance and a conductive film. The composite circuit comprises a battery pack, an LC resonance unit and the conductive film. Two positive electrode connecting ends and two negative electrode connecting ends are led out of the LC resonance unit, each connecting end is provided with a resonance unit switch, and the resonance unit switches on one positive electrode connecting end and one negative electrode connecting end form a pair of resonance unit switches. The battery pack comprises a plurality of battery monomers connected in series, and the positive electrode and the negative electrode of each battery monomer are connected with respective resonance unit switches on the LC resonance unit through two battery monomer switches respectively; wherein the conductive film is coated on the surface of the power battery, and two ends of the conductive film are respectively connected with resonanceunit switches on a positive electrode connecting end and a negative electrode connecting end of the LC resonance unit through connecting switches. The LC resonance unit and the conductive film are used as a part of a circuit, so that the electric quantity can be balanced, and the heat generated in the balancing process can be used for heating the power battery in a low-temperature environment.

Description

technical field [0001] The invention belongs to the technical field of power battery power balance, and in particular relates to a power battery balance and heating composite circuit based on LC resonance and conductive film. Background technique [0002] The existing equalization circuit has two modes of active equalization and passive equalization, which mainly consider the problem of power balance between battery cells, but ignore the heat generated in the process of power balance. In the active equalization circuit, the current formed is relatively large, and the heat generated inside the battery is relatively large, but the heat is not properly utilized. In the passive equalization circuit, the high-power battery is mainly discharged through the energy-consuming resistor, and the heat generated by the energy-consuming resistor is directly dissipated into the air, resulting in waste of energy. [0003] However, in a low-temperature environment, the viscosity of the elec...

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Problems solved by technology

[0002] The existing equalization circuit has two methods of active equalization and passive equalization, which mainly consider the problem of power balance between battery cells, but ignore the heat generated during the process of power balance

In the active equalization circuit, the current formed is larger, and the heat generated inside the battery is more, but the heat has not been rationally utilized

In the passive equalization circuit, the high-power battery is mainly discharged through the energy-consuming resistor, and the heat generated by the energy-consuming resistor is directly dissipated into the air, resulting in energy waste

[0003] However, in a low-temperature environment, the viscosity of the electrolyte will increase and the ion conduction velocity will slow down, resulting in a mismatch in the electron migration velocity of the external circuit, so the battery will be severely polarized, resulting in a sharp decrease in charge and discharge capacity.

In a low temperature environment, lithium ions can easily form lithium dendrites on the surface of the negative electrode, which may pierce the positive and negative electrolyte separators in severe cases, causing the battery to explode

The internal impedance of lithium batteries will also increase in low temperature environments, reducing the performance of lithium batteries

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