Screening method of parallel lithium ion batteries

A lithium-ion battery and screening method technology, applied in the field of screening of parallel lithium-ion batteries, can solve problems such as safety issues, battery cascading failures, failure of the entire battery pack, etc., to improve safety and reliability, and simple execution method Effect

Active Publication Date: 2014-09-03
武汉中原长江科技发展有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0003] When batteries are connected in parallel, if the performance of a battery in the parallel group changes or the self-discharge rate is relatively high, other batteries in the parallel group will charge ...

Method used

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  • Screening method of parallel lithium ion batteries
  • Screening method of parallel lithium ion batteries
  • Screening method of parallel lithium ion batteries

Examples

Experimental program
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Embodiment

[0030] In this embodiment, the screening of 3Ah IFR26650 lithium-ion batteries is used as an example, and 20 single cells to be screened are taken from the same batch, and the following parameters are measured respectively:

[0031] (1) After the first charge-discharge cycle of the single cell, fully charge the single cell, and detect the internal resistance R1 of the battery;

[0032] (2) Discharge to the cut-off voltage, charge 65% of the capacity with a constant current, that is, 1.95Ah, and measure the voltage U1 of the single cell; after 15 to 20 days of storage, detect the voltage U2 of the single cell, discharge to the cut-off voltage, and record the discharge capacity C1;

[0033] (3) Fully charge the above-mentioned single cell again, record the capacity C2 at the end of constant current charging and the total charge capacity C3, and detect the internal resistance R2 of the battery; discharge to the cut-off voltage, and record the discharge capacity C4;

[0034] (4) ...

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Abstract

The invention discloses a screening method of parallel lithium ion batteries, and provides a convenient and effective screening method aiming at the particularity of the parallel battery groups by combining with the static variation and dynamic variation of batteries. The factors to consider for screening are sequentially internal resistance consistency, constant flow charging ratio consistency, voltage pressure consistency, self discharge rate consistency, capacity consistency and charge and discharge characteristic curve matching consistency. The battery performances are judged comprehensively at multiple aspects, so that single battery cells with approximate internal features are screened out, and further parallel battery groups with good consistency are formed by matching; the safety and reliability of the battery groups are improved.

Description

technical field [0001] The invention relates to a screening method for parallel lithium-ion batteries, which belongs to the field of batteries. Background technique [0002] Lithium-ion batteries have the advantages of high voltage, high specific energy, and high specific power, and have become the main candidate power sources for aviation, aerospace, marine equipment, electric vehicles, electric bicycles, ships, military submarines, and torpedoes. In order to meet the application requirements of these electrical equipment, batteries need to be connected in series to a certain voltage level, and battery packs need to be connected in parallel to achieve a higher capacity. [0003] When batteries are connected in parallel, if the performance of a battery in the parallel group changes or the self-discharge rate is relatively high, other batteries in the parallel group will charge the battery, which will affect the self-discharge rate and cycle performance of the entire battery ...

Claims

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Application Information

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IPC IPC(8): B07C5/344
Inventor 李惠吴际良
Owner 武汉中原长江科技发展有限公司
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