CN107505575A - A kind of fast evaluation method of retired electrokinetic cell - Google Patents

Abstract

The present invention relates to Cell Evaluation technical field, discloses a kind of fast evaluation method of retired electrokinetic cell.Including procedure below：Step 1, retired battery bag is placed on testboard, solid measure is carried out to retired battery bag first by charging/discharging apparatus；Step 2, determine again retired battery bag dump energy for 20% when power and internal resistance；Step 3, retired battery bag is fully charged, 1 time-of-week of standing；Step 4, the self-discharge rate for finally determining retired battery bag.The time of retired electrokinetic cell was tapered to 1 week or so from 12 months, the switching time tested between critical parameter is significantly simplify, drastically increases the efficiency of retired battery bag state estimation；Secondly, it greatly ensure that the accuracy of the retired battery status parameter of judge of acquisition.

Description

A rapid evaluation method for decommissioned power batteries

technical field

The invention relates to the technical field of battery evaluation, in particular to a rapid evaluation method for decommissioned power batteries.

Background technique

When the battery has been used for a period of time and the capacity of the battery is less than 80% of the rated capacity of the battery when it is fully charged, the battery should be replaced. Therefore, for the decommissioned battery pack, it is first necessary to determine its actual capacity after decommissioning. With the attenuation of battery capacity, compared with new batteries, the internal resistance of retired battery packs generally increases, the discharge power of batteries will also change, and the consistency of batteries and battery charge retention will deteriorate.

Therefore, the status evaluation of retired battery packs needs to integrate capacity, internal resistance, power, self-discharge rate, and battery consistency to obtain a comprehensive evaluation index. The testing of key parameters such as capacity, internal resistance, power, self-discharge rate, and battery consistency often takes 1-2 months, which will greatly hinder the large-scale utilization of decommissioned power batteries.

Secondly, most of the existing research on power state assessment mainly focuses on the battery model and state estimation algorithm, and a large amount of test data is also needed in the early stage to verify the correctness of the battery model and state estimation algorithm. As for decommissioned power batteries, the working conditions before decommissioning vary greatly, so it is difficult to use a unified battery model and state estimation algorithm to evaluate the state of decommissioned power batteries.

Contents of the invention

The technical problem to be solved by the present invention is: in view of the above existing problems, the present invention extracts the key evaluation factors for judging power batteries, and designs and formulates a set of simple and quick test methods, aiming to achieve the purpose of quickly evaluating decommissioned power batteries , providing a rapid evaluation method for decommissioned power batteries.

The technical scheme adopted in the present invention is as follows: a rapid evaluation method for decommissioned power batteries, including the following process: step 1, place the decommissioned battery pack on the test bench, first use the charging and discharging equipment to measure the capacity of the decommissioned battery pack; step 2 , and then measure the power and internal resistance of the retired battery pack when the remaining power is 20%; step 3, fully charge the retired battery pack, and let it stand for 1 week; step 4, finally measure the self-discharge rate of the retired battery pack.

Further, the specific process of step 1 includes: step 11, the decommissioned battery pack arrives at the workbench 1 of the test bench, discharges the decommissioned battery pack to the cut-off condition of the battery pack with a current of 1C, and stands still for half an hour; step 12, Charge the decommissioned battery pack with a current of 0.5C and let it stand for half an hour; step 13, discharge the decommissioned battery pack with a current of 1C, the capacity released by the decommissioned battery pack is the actual capacity of the decommissioned battery pack, and obtain the decommissioned battery pack The actual capacity of the battery pack.

Further, the rapid evaluation method of the decommissioned power battery also includes the following process: after the completion of the step 1, the decommissioned battery pack primary battery management system is used to detect and obtain the voltage conditions of all the cells of the decommissioned battery pack.

Further, the specific process of step 2 includes: the decommissioned battery pack arrives at the workbench 2 on the test bench from workbench 1, charges or discharges the decommissioned battery pack with a current of 1C until the remaining power is 20%, and stands still for half an hour ; Then test the power and internal resistance of the decommissioned battery pack with a current of 1C, and obtain the power and internal resistance when the remaining power of the decommissioned battery pack is 20%, and record it.

Further, in step 3, after the decommissioned battery pack is fully charged, the decommissioned battery pack is moved from the workbench 2 to the static storage area on the test bench, and then left to stand for 1 week.

Further, the specific process of step 4 includes: the decommissioned battery pack arrives at the workbench 3 of the test bench from the static storage area, and discharges the decommissioned battery pack to the cut-off voltage with a current of 1C. At this time, the discharged capacity of the decommissioned battery pack is the same as The ratio of the actual capacity of the retired battery pack is the self-discharge rate of the retired battery pack.

Compared with the prior art, the beneficial effects of adopting the above technical solution are:

1. By establishing a test assembly line, the actual capacity, voltage consistency, power and internal resistance, and self-discharge rate are respectively tested on the assembly line, which reduces the test time of the usually decommissioned power battery from 1-2 months to about 1 week. It significantly simplifies the switching time of the test between the evaluation parameters, and greatly improves the efficiency of the status evaluation of the decommissioned battery pack.

2. The present invention extracts the key parameters of the decommissioned power battery, formulates a simple and fast test method, and directly measures the key test indicators of each decommissioned battery pack, which greatly ensures the accuracy of the obtained decommissioned battery status parameters.

Description of drawings

Fig. 1 is a schematic flow chart of the rapid evaluation method for decommissioned power batteries of the present invention.

detailed description

The present invention will be further described below in conjunction with the accompanying drawings.

As shown in Figure 1, an assembly line test bench is set up for the measurement of decommissioned battery packs, and the actual capacity, voltage consistency, power and internal resistance are measured on different work benches, and the self-discharge rate parameters are evaluated. Set workbench 1, workbench 2, static storage area, and workbench 3 in sequence. Workbench 1 is equipped with a set of power supply and load equipment, the purpose of which is to complete the battery capacity test through charging and discharging; workbench 2 is equipped with power and internal resistance test equipment, the purpose is to complete the battery in the case of low remaining power (SOC). Discharge capacity test; workbench 3 is equipped with a separate load device, the purpose is to complete the self-discharge of the battery after standing for a week.

1. Obtain the actual capacity of the decommissioned battery pack

The retired battery pack arrives at workbench 1 of the test bench, discharges the retired battery pack to the cut-off condition of the battery pack with a current of 1C, and stands still for half an hour; charges the retired battery pack with a current of 0.5C, and stands still for half an hour; The current of 1C discharges the decommissioned battery pack, the capacity released by the decommissioned battery pack is the actual capacity of the decommissioned battery pack, and the actual capacity shown is also the remaining capacity of the decommissioned battery pack when decommissioned, and the actual capacity of the decommissioned battery pack is obtained. At the same time, the primary battery management system of the decommissioned battery pack is used to detect and obtain all the voltage conditions of the decommissioned battery packs.

2. Measure the power and internal resistance of retired battery packs

For the power measurement of the decommissioned battery pack, only the power under the low remaining power (SOC) is needed. In this embodiment, the SOC is 20%. The battery pack is charged or discharged with a current of 1C until the remaining power is 20%, and then left for half an hour; then the power and internal resistance of the retired battery pack are tested with a current of 1C. The test process can refer to the national standard GB/T 31467.2-2015 Under the power and internal resistance test conditions, the power and internal resistance of the decommissioned battery pack when the remaining power is 20% are obtained and recorded.

3. After measuring the power and internal resistance, fully charge the decommissioned battery pack, and then the decommissioned battery pack arrives at the static storage area for 1 week.

The static storage area includes battery racks for placing decommissioned battery packs. The battery packs tested from workbench 2 enter the static storage area along with the conveyor belt, and are sequentially and orderly placed on the battery racks. After the battery packs on the workbench 3 leave the workbench 3 after finishing the test and reach the set rest time, the battery racks in the rest storage area sequentially send the battery packs to be tested for self-discharge to the conveyor belt. Therefore, the static storage area can ensure the smooth completion of various tests of the decommissioned battery pack.

4. Determining the self-discharge rate of retired battery packs

The decommissioned battery pack arrives at the workbench 3 of the test bench from the static storage area, and the decommissioned battery pack is discharged to the cut-off voltage with a current of 1C. At this time, the ratio of the discharged capacity of the decommissioned battery pack to the actual capacity of the decommissioned battery pack is the decommissioned battery The self-discharge rate of the package.

The present invention is not limited to the foregoing specific embodiments. The present invention extends to any new feature or any new combination disclosed in this specification, and any new method or process step or any new combination disclosed. Any insubstantial changes or improvements made by those skilled in the art without departing from the spirit of the present invention shall all fall within the protection scope of the claims of the present invention.

Claims (6)

1. a kind of fast evaluation method of retired electrokinetic cell, it is characterised in that including procedure below：Step 1, by retired battery Bag is placed on testboard, and solid measure is carried out to retired battery bag first by charging/discharging apparatus；Step 2, determine again it is retired Power and internal resistance when battery bag dump energy is 20%；Step 3, retired battery bag is fully charged, 1 time-of-week of standing；Step 4, Finally determine the self-discharge rate of retired battery bag.

2. the fast evaluation method of retired electrokinetic cell as claimed in claim 1, it is characterised in that the step 1 it is specific Process includes：Step 11, retired battery bag reach the workbench 1 of testboard, and retired battery bag is discharged into electricity with 1C electric current Chi Bao blanking voltage, stand half an hour；Step 12, with 0.5C electric current retired battery bag is charged, stand half an hour； Step 13, with 1C electric current retired battery bag is discharged, the capacity that retired battery bag is released is that retired battery bag is real Border capacity, obtain the retired battery bag actual capacity.

3. the fast evaluation method of retired electrokinetic cell as claimed in claim 2, it is characterised in that the retired electrokinetic cell Fast evaluation method also include procedure below：After the step 1 is completed, examined using retired battery bag galvanic cell management system Survey and obtain all monomer voltage situations of retired battery bag.

4. the fast evaluation method of retired electrokinetic cell as claimed in claim 3, it is characterised in that the step 2 it is specific Process includes：Retired battery bag reaches the workbench 2 on testboard from workbench 1, and retired battery bag is charged with 1C electric current Or it is 20% to be discharged to dump energy, stands half an hour；Then power is carried out to retired battery bag with 1C electric current and internal resistance is surveyed Examination, power when retired battery bag dump energy is 20% and internal resistance are obtained, and recorded.

5. the fast evaluation method of retired electrokinetic cell as claimed in claim 4, it is characterised in that in the step 3, will move back After labour battery bag is fully charged, standing storage area of the retired battery bag from workbench 2 to testboard, 1 time-of-week is then stood.

6. the fast evaluation method of retired electrokinetic cell as claimed in claim 5, it is characterised in that the step 4 it is specific Process includes：Retired battery bag reaches the workbench 3 of testboard from storage area is stood, and retired battery bag is discharged with 1C electric current To blanking voltage, the ratio of capacity and retired battery bag actual capacity that now retired battery bag is released, as retired battery bag Self-discharge rate.