Screening method of consistence of lithium-ion battery pack

A technology for a lithium-ion battery pack and a screening method, which is applied in the direction of measuring electricity, measuring electrical variables, measuring devices, etc., can solve the problems of low cycle life, low battery pack capacity, and reduced charging window, and achieves simple execution method, Improve safety and reliability, facilitate the effectiveness of effective screening methods

Inactive Publication Date: 2019-01-22
TIANJIN LISHEN BATTERY
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0003] When single batteries are connected in series and parallel to form a module, not only the capacity of the battery pack is lower than the sum of the capacities of the single batteries, bu

Method used

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  • Screening method of consistence of lithium-ion battery pack

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Embodiment

[0023] In this embodiment, a 75Ah LP2222197 lithium-ion battery is used as an example, and the specific steps are as follows:

[0024] In the first step, the battery is charged at 0.33C constant current and constant voltage, the cut-off current is 0.05C, and then discharged at 0.33C constant current to 2.5V. After charging and discharging twice, the battery is charged at constant current and constant voltage to 3.65V to ensure the consistency of each battery voltage; record the second discharge capacity at the same time, and screen out batteries with a ratio of capacity to rated capacity of 1-1.03;

[0025] The second step is to stand at room temperature for 48h±4h to promote the stability of the battery state;

[0026] The third step is to conduct a group series test of 8 groups of batteries after standing at room temperature, record the initial voltage data V1 of each battery, and then perform a 2C current pulse discharge on the series battery group for 10s, and record the v...

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Abstract

The invention discloses a screening method of the consistence of a lithium-ion battery pack. The method includes following steps: firstly, screening the consistence of the capacity of batteries; secondly, performing normal-temperature static placement for 48 h+/-4 h; thirdly, conducting grouped serial connection tests on the batteries, and recording initial voltage data V1 and a battery DC internal resistance DCIR1 of each battery; fourthly, performing normal-temperature aging for 14 days in the condition of 25 DEG C+/-3 DEG C; fifthly, recording voltage data V2 after battery aging, and screening the consistence of self-discharge rates of the batteries; sixthly, calculating a DC internal resistance DCIR2 of each battery, and screening the consistence of the internal resistances of the batteries; and seventhly, drawing a V-T curve of pulse discharging of the batteries, performing classification by regarding a dynamic voltage difference of 30 mV as an interval, and storing the tested batteries in a classified manner. According to the screening method of the consistence of the battery pack, based on the static consistence and the dynamic consistence of the batteries, the operation method is simple, the reliability of test results is high, and the practical condition of the battery pack is satisfied.

Description

technical field [0001] The invention relates to the technical field of lithium ion batteries, in particular to a method for screening the consistency of lithium ion battery packs. Background technique [0002] Lithium-ion batteries have the advantages of high energy density, long cycle life, low self-discharge rate, and environmental friendliness. They have been widely used in portable electronic devices such as mobile phones, Bluetooth headsets, and notebook computers. In recent years, with the implementation of new energy vehicles, Its application in power batteries, energy storage batteries and other fields is also constantly improving. In order to meet the power demand of equipment, it is usually necessary to connect single cells in series and in parallel to achieve a certain voltage and capacity level. [0003] When single batteries are connected in series and parallel to form a module, not only the capacity of the battery pack is lower than the sum of the capacities o...

Claims

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Application Information

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IPC IPC(8): G01R31/378G01R31/392
Inventor 李亚娥张绍丽蔡昌彬张坤卜绍乾丁正平伍绍中
Owner TIANJIN LISHEN BATTERY
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