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Lithium ion battery screening method

A lithium-ion battery and screening method technology, which is applied in the field of battery testing, can solve the problems of battery pack performance attenuation and inconsistent battery performance trend, and achieve good consistency, good promotion, and good long-term cycle performance.

Active Publication Date: 2015-04-01
SHANGHAI POWER ENERGY STORAGE BATTERY SYST ENG TECH +3
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The problem that this method is likely to cause is that the same state of the battery at a specific moment does not mean the same state of the battery in the future. Grouping batteries with similar performance at the current moment can achieve good consistency in a short period of time, but for long-term cycle use The inconsistency of the battery performance change trend will lead to a sharp decline in the performance of the battery pack

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0043] Embodiment 1, a 10Ah single battery is taken as an example.

[0044] Initial state test of battery production: Fix the 10Ah battery cell produced by the production line on the battery testing equipment, use the information scanning device to obtain its code information, set the charging to 2.8V at a constant current of 10A, and charge at a constant voltage of 2.8V to a current of 0.5A , put it on hold for 30min, and discharge it to 1.6V with a constant current of 10A. Record the discharge capacity as C1, use the internal resistance tester to test its open circuit voltage and AC internal resistance, and record them as U1 and R1 respectively.

[0045] According to the battery use environment, the battery is charged and discharged once, charged at 1C constant current to 2.7V, discharged to 1.6V, and its capacity, open circuit voltage and AC internal resistance are respectively recorded as C2, U2 and R2.

[0046] Put the battery on hold for 7 days, then perform a charge-di...

Embodiment 2

[0051] In the second embodiment, a power battery that does not meet the use standard is taken as an example.

[0052] Reclassify and group batteries that do not meet the standard for power batteries, so that they can be used in other applications, such as energy storage, EPS, street lights and other occasions that require relatively low battery performance. The power battery obtains its C1, U1 and R1 through its standard test when it leaves the factory.

[0053]When the battery capacity is reduced to 80% of the rated capacity, it is considered unsuitable to be used as a power battery, and it is tested, taking the standard 18650LFP as an example, charging to 3.6V at 2.2A, constant voltage to 0.11A, and 2.2 A discharge to 2.5V, record its C2, U2 and R2.

[0054] Set aside for 10 days and use the same method as step 2, record its C2, U3 and R3, and calculate ΔC1, ΔC2, ΔU1, ΔU2, ΔR1, ΔR2.

[0055] C1≥2200mAh, C2≥1760mAh, C3≥1700mAh, ΔC1≤500mAh, ΔC2≤100mAh, in this standard, ΔC2 ...

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Abstract

The invention discloses a lithium ion battery screening method. The lithium ion battery screening method is characterized by comprising the following steps of 1, acquiring coding information of multiple battery cells, 2, carrying out an initial charging-discharging cycle of the multiple battery cells, 3, carrying out a charging-discharging cycle of the multiple battery cells according to a battery use environment, 4, respectively calculating differences of capacitances, voltages and alternating current impedances measured by the step 2 and the step 3, 5, carrying out multiple battery cell arrangement, carrying out battery information acquisition, and carrying out a charging-discharging cycle of the multiple battery cells, 6, respectively calculating differences of capacitances, voltages and alternating current impedances measured by the step 3 and the step 5, 7, carrying out classification according to a classification standard, and 8, dividing the multiple battery cells into multiple groups. The lithium ion battery screening method can realize screening of cells according to similar performance and performance variation trend, maximumly reduce the possibility of cell degradation inconformity, and guarantee stable battery performances.

Description

technical field [0001] The invention relates to the technical field of battery detection, in particular to a lithium ion battery screening method. Background technique [0002] As one of the most popular green batteries, lithium-ion batteries have become a new force in the battery market due to their advantages such as high specific energy, long life, high open circuit voltage, low self-discharge rate, environmental friendliness, and low price. As lithium-ion batteries are widely used in civilian fields (mobile phones, notebooks, cameras, electric toys), their safety and practicality have been well received by the industry. At present, lithium-ion batteries have developed rapidly in the direction of high power, high specific energy, and high cycle life. Electric vehicles powered by lithium-ion batteries will gradually replace some fuel vehicles; large-scale lithium-ion stacks are used as energy storage devices. into energy storage power stations and smart grid systems. [...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): B07C5/344
Inventor 黄嘉烨晏莉琴冯毅解晶莹张宇苏广宁刘隽
Owner SHANGHAI POWER ENERGY STORAGE BATTERY SYST ENG TECH