阅读说明：本技术 一种锂离子实验电池测试筛选方法 (Lithium ion experimental battery testing and screening method ) 是由 王忠一 辛悦 于 2020-06-18 设计创作，主要内容包括：本发明提出的一种锂离子实验电池测试筛选方法,包括以下步骤：首先将测试项分类；然后测试交流内阻差ΔR以及用于评估待测试电池在加压环境中每天的电压损失的K值,并结合交流内阻差ΔR以及K值对待测试电池进行分类,获得多个待测类别；对应每一个待测类别,分别从各类测试项中选取一个测试项组成对应的测试指标集合；对应每一个待测类别中的待测试电池,根据对应的测试指标集合中的测试项进行测试和评估。本发明不仅方法简单、高效、实用,能准确的筛选出合格电池,而且可以把合格电池分类然后合理的分配给需要测试的项目,从而提高测试电池性能的一致性、准确性,真实的反应实验电池应有的性能水平。(The invention provides a lithium ion experimental battery testing and screening method, which comprises the following steps: firstly, classifying test items; then testing the alternating current internal resistance difference delta R and a K value for evaluating the voltage loss of the battery to be tested in a pressurizing environment every day, and classifying the battery to be tested by combining the alternating current internal resistance difference delta R and the K value to obtain a plurality of categories to be tested; corresponding to each category to be tested, selecting one test item from various test items to form a corresponding test index set; and corresponding to the batteries to be tested in each category to be tested, and testing and evaluating according to the test items in the corresponding test index set. The method is simple, efficient and practical, qualified batteries can be accurately screened out, and the qualified batteries can be classified and then reasonably distributed to items to be tested, so that the consistency and the accuracy of the performance of the tested batteries are improved, and the performance level of the tested batteries is truly reflected.)

1. A lithium ion experimental battery testing and screening method is characterized by comprising the following steps:

s1, classifying the test items;

s2, testing the alternating current internal resistance difference delta R and a K value for evaluating the voltage loss of the battery to be tested in the pressurizing environment every day, and classifying the electrical test to be tested by combining the alternating current internal resistance difference delta R and the K value to obtain a plurality of categories to be tested;

s3, corresponding to each category to be tested, selecting a test item from various test items to form a corresponding test index set;

and S4, testing and evaluating corresponding to the batteries to be tested in each category to be tested according to the test items in the corresponding test index set.

2. The method for testing and screening lithium ion experimental batteries according to claim 1, wherein in step S1, the classification result of the test items is:

the first type of test item includes: circulating charge and discharge times;

the second type of test items includes: laying aside and discharging at different temperatures;

the third category of test items includes: HPPC, rate charging, rate discharging;

the fourth type of test item includes: constant volume, over-filling, over-discharging, short circuit, needling, extruding, heating and temperature circulation;

the fifth category of test items includes: soaking in seawater, lowering air pressure, and dropping.

3. The method for testing and screening lithium ion experimental batteries according to claim 1, wherein the step S2 specifically comprises the following steps:

s21, screening batteries to be tested, dividing the capacities of the batteries to be tested, and testing a first open-circuit voltage U1 and a first alternating current internal resistance R1;

s22, placing the batteries to be tested for a first time value in a pressurizing environment, and then testing a second open-circuit voltage U2, a second alternating current internal resistance R2, a battery weight G1 and a battery thickness H1 of each battery to be tested;

s23, calculating an alternating current internal resistance difference delta R and a K value according to the first open-circuit voltage U1, the first alternating current internal resistance R1, the second open-circuit voltage U2 and the second alternating current internal resistance R2, wherein the alternating current internal resistance difference delta R is a difference value between the second alternating current internal resistance R2 and the first alternating current internal resistance R1;

and S24, classifying the electric test to be tested by combining the alternating current internal resistance difference delta R and the K value to obtain a plurality of categories to be tested.

4. The method for testing and screening the lithium ion experimental battery as claimed in claim 3, wherein in the step S21, the battery to be tested is subjected to capacity grading and then is left standing for 24h, and then the first open-circuit voltage U1 and the first alternating current internal resistance R1 are tested.

5. The method for testing and screening lithium ion experimental batteries according to claim 3, wherein in step S21, the capacity of the batteries to be tested after capacity grading is 2% -5% SOC.

6. The method for testing and screening lithium ion experimental batteries according to claim 3, wherein the step S22 is specifically that 5 to 15 batteries to be tested are pressed and packed by a packer, and then placed at room temperature for a first time value, and then unpacked, and the second open-circuit voltage U2 and the second internal alternating current resistance R2 of each battery to be tested are tested.

7. The method for screening tests for lithium ion batteries according to claim 6, wherein the first time value is 7 days.

8. The method for testing and screening lithium ion experimental batteries according to claim 6, wherein the packing force of the packing machine is 1.05 ± 0.05 kN.

9. The method for testing and screening lithium ion experimental batteries according to claim 3, wherein in step S23,. DELTA.R-R2-R1; k ═ U1-U2/days of rest.

10. The method of claim 3, wherein in step S24, the test electric test is first screened according to the AC internal resistance difference Δ R and K, and the screened test batteries are classified according to the AC internal resistance difference Δ R and K.

Technical Field

The invention relates to the technical field of lithium ion batteries, in particular to a test screening method for a lithium ion experimental battery.

Background

The lithium ion battery electrical performance test and the safety performance test are two important means for evaluating the performance of the battery cell, and the test battery cell can directly represent the overall performance of the battery cell in a small test, a middle test and even a mass production to a certain extent, so the test and screening work of the battery cell is very important. At present, the lithium ion battery used for testing generally comes from laboratory lab scale experiment and production line pilot scale experiment, there is not actual standard to the screening of test electric core, only according to the present data of making of battery carry out simple screening, unscientific, unreasonable test performance and security performance test of sending and survey probably lead to electric core test result uniformity very poor, electric core performance can not reach the design standard, still can apply retest sometimes, the original performance level of electric core is not proved, cause certain interference for follow-up design development.

Disclosure of Invention

Based on the technical problems in the background art, the invention provides a lithium ion experimental battery testing and screening method.

The invention provides a lithium ion experimental battery testing and screening method, which comprises the following steps:

s1, classifying the test items;

s2, testing the alternating current internal resistance difference delta R and a K value for evaluating the voltage loss of the battery to be tested in the pressurizing environment every day, and classifying the electrical test to be tested by combining the alternating current internal resistance difference delta R and the K value to obtain a plurality of categories to be tested;

s3, corresponding to each category to be tested, selecting a test item from various test items to form a corresponding test index set;

and S4, testing and evaluating corresponding to the batteries to be tested in each category to be tested according to the test items in the corresponding test index set.

Preferably, in step S1, the test item classification result is:

the first type of test item includes: circulating charge and discharge times;

the second type of test items includes: laying aside and discharging at different temperatures;

the third category of test items includes: HPPC, rate charging, rate discharging;

the fourth type of test item includes: constant volume, over-filling, over-discharging, short circuit, needling, extruding, heating and temperature circulation;

the fifth category of test items includes: soaking in seawater, lowering air pressure, and dropping.

Preferably, step S2 specifically includes the following steps:

s21, screening batteries to be tested, dividing the capacities of the batteries to be tested, and testing a first open-circuit voltage U1 and a first alternating current internal resistance R1;

s22, placing the batteries to be tested for a first time value in a pressurizing environment, and then testing a second open-circuit voltage U2, a second alternating current internal resistance R2, a battery weight G1 and a battery thickness H1 of each battery to be tested;

s23, calculating an alternating current internal resistance difference delta R and a K value according to the first open-circuit voltage U1, the first alternating current internal resistance R1, the second open-circuit voltage U2 and the second alternating current internal resistance R2, wherein the alternating current internal resistance difference delta R is a difference value between the second alternating current internal resistance R2 and the first alternating current internal resistance R1;

and S24, classifying the electric test to be tested by combining the alternating current internal resistance difference delta R and the K value to obtain a plurality of categories to be tested.

Preferably, in step S21, the battery to be tested is placed for 24 hours after capacity grading, and then the first open-circuit voltage U1 and the first ac internal resistance R1 are tested.

Preferably, in step S21, the capacity of the battery to be tested after capacity grading is 2% to 5% SOC.

Preferably, in step S22, the batteries to be tested are pressed and packed by a packing machine in a group of 5-15 batteries, and then placed at room temperature for a first time value, and then unpacked, and the second open-circuit voltage U2 and the second alternating current internal resistance R2 of each battery to be tested are tested.

Preferably, the first time value is 7 days.

Preferably, the baling force of the baling press is 1.05 +/-0.05 kN.

Preferably, in step S23, Δ R ═ R2-R1; k ═ U1-U2/days of rest.

Preferably, in step S24, the alternating current internal resistance difference Δ R and the K value are combined to screen the to-be-tested electric tests, and the screened to-be-tested batteries are classified according to the alternating current internal resistance difference Δ R and the K value.

The invention provides a lithium ion experimental battery test screening method which comprises the steps of firstly, determining test items, evaluating the degree grade of the test items influencing the performance of a battery core, and classifying the test items. Second, cells for alternative testing are simply screened and sorted according to the method of the invention. And finally, matching the classified battery with the classified test item.

The lithium ion experimental battery testing and screening method provided by the invention is simple, efficient and practical, can accurately screen out qualified batteries, and can classify the qualified batteries and reasonably distribute the qualified batteries to items to be tested, so that the consistency and the accuracy of the performance of the tested batteries are improved, and the performance level of the experimental batteries is truly reflected.

Meanwhile, the battery classification test can be carried out, so that the battery test can better meet the project requirements, and the batteries of different types can be conveniently applied according to the test characteristics.

Drawings

FIG. 1 is a flow chart of a lithium ion experimental battery testing and screening method provided by the invention;

FIG. 2 is a flow chart of a battery sorting method according to the present invention.

Detailed Description