CN114247663B - Single battery sorting method for producing lithium ion battery pack - Google Patents
Single battery sorting method for producing lithium ion battery pack Download PDFInfo
- Publication number
- CN114247663B CN114247663B CN202111559764.0A CN202111559764A CN114247663B CN 114247663 B CN114247663 B CN 114247663B CN 202111559764 A CN202111559764 A CN 202111559764A CN 114247663 B CN114247663 B CN 114247663B
- Authority
- CN
- China
- Prior art keywords
- battery
- voltage
- discharge
- current
- preset threshold
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 title claims abstract description 21
- 229910001416 lithium ion Inorganic materials 0.000 title claims abstract description 21
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 9
- 238000000034 method Methods 0.000 claims abstract description 38
- 238000007600 charging Methods 0.000 claims abstract description 32
- 238000010277 constant-current charging Methods 0.000 claims abstract description 26
- 230000003068 static effect Effects 0.000 claims abstract description 17
- 238000012216 screening Methods 0.000 claims description 18
- 238000004364 calculation method Methods 0.000 claims description 7
- 238000007599 discharging Methods 0.000 claims description 7
- 238000010280 constant potential charging Methods 0.000 claims description 3
- 238000003064 k means clustering Methods 0.000 claims description 3
- 230000010287 polarization Effects 0.000 abstract description 8
- 238000012360 testing method Methods 0.000 abstract description 4
- 230000000694 effects Effects 0.000 abstract description 2
- 230000007613 environmental effect Effects 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000004146 energy storage Methods 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 230000000284 resting effect Effects 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B07—SEPARATING SOLIDS FROM SOLIDS; SORTING
- B07C—POSTAL SORTING; SORTING INDIVIDUAL ARTICLES, OR BULK MATERIAL FIT TO BE SORTED PIECE-MEAL, e.g. BY PICKING
- B07C5/00—Sorting according to a characteristic or feature of the articles or material being sorted, e.g. by control effected by devices which detect or measure such characteristic or feature; Sorting by manually actuated devices, e.g. switches
- B07C5/34—Sorting according to other particular properties
- B07C5/344—Sorting according to other particular properties according to electric or electromagnetic properties
Abstract
The invention discloses a single battery sorting method for producing a lithium ion battery pack, which comprises the following steps: measuring constant-current charging static voltage V of battery to be sorted 2 The method comprises the steps of carrying out a first treatment on the surface of the Measuring the discharge capacity C of the battery at a certain discharge current 2 The method comprises the steps of carrying out a first treatment on the surface of the After the rest, measuring the battery voltage to obtain the discharge termination rebound voltage V 4 The method comprises the steps of carrying out a first treatment on the surface of the After charging the battery by a certain mechanism, placing the battery for 2-28 days under a certain temperature T condition; measuring voltage V of the battery after rest 5 And an internal resistance R; according to the discharge capacity C of the battery 2 Constant current charging quiescent voltage V 2 Voltage V of discharge termination rebound 4 Voltage after rest V 5 And the internal resistance R is used for sorting the batteries to be sorted. According to the method, the actual charge and discharge working conditions of the battery pack are considered, the battery is subjected to charge and discharge test by the actual working current, the battery capacity under the actual working conditions is obtained, the dynamic characteristics of the battery are reflected by the polarization voltage of the battery under the actual working conditions, and the sorting precision is high and the effect is good.
Description
Technical Field
The invention belongs to the technical field of batteries, and particularly relates to a single battery sorting method for producing a lithium ion battery pack.
Background
The lithium ion battery has the advantages of high specific energy, long cycle life, safety, environmental protection and the like, and is widely applied to the fields of electric automobiles, electric tools, energy storage systems and the like. However, the voltage of the lithium ion single battery is only about 3.2-3.7V, and the single battery is limited in single capacity, so that the single battery cannot meet the requirements of an electric load on battery energy and power. In order to increase the voltage and capacity of the battery, the single batteries are required to be combined into a battery pack in a parallel connection and series connection mode so as to meet the requirements of an electric load on the energy and the power of the battery. The lithium ion battery pack is formed by combining a large number of single batteries in a serial-parallel connection mode, which means that the performance of the battery pack is influenced by a wooden barrel effect, namely the performance of the battery pack is determined by the single battery with the worst quality in the battery pack. Because of batch inconsistency of raw materials in the actual production process, environmental factors and the like, the parameters such as capacity, internal resistance and the like of the single batteries of the same type produced in the same batch show differences, namely inconsistency. And once the differences are beyond a certain interval range, the performance of the whole battery is obviously affected. Therefore, before the battery combination, the single batteries are subjected to grouping and sorting, and the batteries with the parameter differences of discharge capacity, internal resistance, voltage, self-discharge rate and the like within a certain range are sorted and combined together in series-parallel connection after the grouping.
At present, lithium ion battery pack production mainly carries out sorting and grouping according to static characteristic parameters of single batteries, generally firstly carries out capacity sorting on the single batteries to obtain the discharge capacity of the batteries under a certain charge-discharge mechanism, then measures the internal resistance and the voltage of the batteries after the batteries are placed for a certain time, and then completes sorting of the batteries according to the capacity, the internal resistance and the voltage data of the batteries. The method has short screening time and high efficiency, but can only ensure the consistency of the static characteristic parameters of the screened single batteries, and can not reflect the dynamic characteristics of the batteries in the working process. On the other hand, the battery capacity data according to the existing sorting process is often obtained under specific charging and discharging conditions, the actual charging and discharging current and the actual working voltage interval of the battery pack are not considered, and after the single batteries obtained by sorting and matching are assembled into the battery pack, new inconsistency is likely to be displayed under the actual working condition. Therefore, it is necessary to develop a battery sorting method that can reflect both the dynamic operating characteristics and the static parameters of the battery while considering the actual operating conditions of the battery pack.
The dynamic operating characteristics of the battery are closely related to the battery polarization. The polarization of the battery exists, so that the charge and discharge potential of the battery tends to deviate from the balance potential in the working process, and the greater the polarization, the greater the deviation degree. Thus, the polarization voltage of the battery at a certain operating current can be used to characterize the dynamic characteristics of the battery when in operation. When the battery is sorted, static characteristic parameters such as capacity, internal resistance, self-discharge rate and the like of the battery under actual working conditions and polarization voltage can be comprehensively sorted, and consistency of the static characteristic and dynamic characteristic of the sorted battery is ensured.
Disclosure of Invention
Aiming at the defects of the prior art, the invention provides a single battery sorting method for producing a lithium ion battery pack, which sorts according to the static characteristic parameter and the dynamic characteristic parameter of the battery at the same time, and has high sorting efficiency and good consistency.
In order to solve the technical problems, the invention adopts the following technical scheme: a single battery sorting method for producing lithium ion battery pack determines charging current I of the single battery sorting method according to nominal parameters of the produced lithium ion battery pack 1 Cut-off voltage of charge V 1 Discharge current I 2 And discharge cut-off voltage V 3 Charging current I 1 Charging current I for a battery pack C 1/n, n is the parallel number of single battery cells of the battery pack, and the charging cut-off voltage V 1 The charge cut-off voltage of the battery pack is 1/m, m is the serial number of the single batteries of the battery pack, and the discharge current I 2 1/n of rated discharge current of the battery pack, n is the parallel number of single battery cells of the battery pack, and the discharge cut-off voltage V 3 The method for sorting the single batteries comprises the following steps that 1/m of the lowest discharge voltage of the battery pack is 1/m of the lowest discharge voltage of the battery pack, m is the serial number of the single batteries of the battery pack:
step 1: with charging current I 1 Constant current charging is carried out on single batteries to be sortedCharged to a charge cut-off voltage V 1 ；
Step 2: after the battery is placed for 30 to 120 minutes, the voltage of the battery is measured to obtain the constant-current charging static voltage V of the battery 2 ；
Step 3: continue to use I 1 Constant-current and constant-voltage charging of the battery to V by current 1 Charging off current I 0 ；
Step 4: at discharge current I 2 Constant-current discharging of fully charged battery to discharge cut-off voltage V 3 Obtaining the discharge capacity C of the battery 2 ；
Step 5: after 3-120 minutes of rest, measuring the voltage of the battery to obtain the discharge termination rebound voltage V 4 ，
Step 6: with charging current I 3 Constant-current charging is carried out on the discharged battery for t minutes;
step 7: the battery is placed for 2-28 days under the condition of a certain temperature T;
step 8: measuring voltage V of the battery after rest 5 And an internal resistance R;
step 9: according to the discharge capacity C of the battery 2 Constant current charging quiescent voltage V 2 Voltage V of discharge termination rebound 4 Voltage after rest V 5 And the internal resistance R is used for sorting the batteries to be sorted.
In the step 7, the certain temperature T is between normal temperature and 60 ℃.
In the step 9, the single battery to be sorted is sorted by adopting a clustering method based on a variation coefficient and a relative deviation, and the method specifically comprises the following steps:
1) Calculating the discharge capacity C of the single battery to be sorted 2 Average value C of (2) 2a And mean square error C 2s If the coefficient of variation C 2s /C 2a Greater than a first preset threshold epsilon 1 Then remove |C 2 -C 2a The battery with the largest value is recalculated to calculate the remaining battery C 2 Average value C of (2) 2a / And mean square error C 2s / Up to C 2s / /C 2a / Less than or equal to a first preset threshold epsilon 1 Entering step 2);
2) If the relative deviation |C of the discharge capacity of the battery entering this step 2 -C 2a / |/C 2a / Greater than a second preset threshold epsilon 2 Judging that the battery is disqualified in the matching, screening the battery, and entering the rest battery into the step 3);
3) Calculating constant-current charging static voltage V of battery entering the step 2 Average value V of (2) 2a And mean square error V 2s If the coefficient of variation V 2s /V 2a Greater than a third preset threshold epsilon 3 Then screen out |V 2 -V 2a The battery with the largest value is recalculated to calculate the remaining battery V 2 Average value V of (2) 2a / And mean square error V 2s / Up to V 2s / /V 2a / Less than or equal to a third preset threshold epsilon 3 Step 4) is entered;
4) If the battery V of the step is entered 2 Is of the relative deviation |V 2 -V 2a / |/V 2a / Greater than a fourth preset threshold epsilon 4 Judging that the battery is disqualified in the matching, screening the battery, and entering the rest battery into the step 5);
5) Calculating the discharge termination rebound voltage V of the battery entering this step 4 Average value V of (2) 4a And mean square error V 4s If the coefficient of variation V 4s /V 4a Greater than a fifth preset threshold epsilon 5 Then screen out |V 4 -V 4a The battery with the largest value is recalculated to calculate the remaining battery V 4 Average value V of (2) 4a / And mean square error V 4s / Up to V 4s / /V 4a / Less than or equal to a fifth preset threshold epsilon 5 Step 6) is entered;
6) If enter battery |V of this step 4 -V 4a / |/V 4a / Greater than a sixth preset threshold epsilon 6 Judging that the battery is disqualified in the matching, screening the battery, and entering the step 7 by the residual battery;
7) Calculating the voltage V of the battery entering the step 5 Average value V of (2) 5a And mean square error V 5s If the coefficient of variation V 5s /V 5a Greater than a seventh preset threshold epsilon 7 Then screen out |V 5 -V 5a The battery with the largest value is recalculated to calculate the remaining battery V 5 Average value V of (2) 5a / And mean square error V 5s / Up to V 5s / /V 5a / Less than or equal to a seventh preset threshold epsilon 7 Step 8) is entered;
8) If enter battery |V of this step 5 -V 5a / |/V 5a / Greater than an eighth preset threshold epsilon 8 Judging that the battery is disqualified in the matching, screening the battery, and entering the rest battery into the step 9);
9) Calculating the average value R of the internal resistance R of the battery entering the step a And mean square error R s If the coefficient of variation R s /R a Greater than a ninth preset threshold epsilon 9 Then remove |R-R a The battery with the largest value is used for recalculating the average value R of the residual batteries R a / And mean square error R s / Up to R s / /R a / Less than or equal to a ninth preset threshold epsilon 9 Step 10) is entered;
10 If enter battery |R-R of this step a / |/R a / Greater than a tenth preset threshold epsilon 10 And judging that the batteries are disqualified in battery allocation, screening the batteries, and finishing battery allocation.
In the step 9, the single batteries to be sorted are sorted by adopting a K-means clustering method, a mean shift clustering method or a DBSCAN clustering method.
The beneficial effects of the invention are as follows:
1. the invention considers the actual charge and discharge working condition of the battery pack, performs charge and discharge test on the battery by using the actual working current to obtain the battery capacity under the actual working condition, reflects the dynamic characteristics of the battery by using the polarization voltage of the battery under the actual working condition, has high sorting precision, and the battery performance after grouping is obviously superior to that of the battery pack obtained by static sorting.
2. The invention selects the constant current charging static voltage V 2 As a parameter reflecting the charge polarization, the consistency of the single battery at the charge end of the battery pack can be ensured, the overcharge of the single battery is effectively prevented, and the cycle performance and the safety of the battery pack are improved.
3. Compared with the traditional battery sorting, the invention adds the constant-current charging static voltage V only in the battery capacity testing stage 2 And discharge termination rebound voltage V 4 The method is simple and the separation efficiency is high.
Drawings
Fig. 1 is a schematic diagram of a method for sorting unit cells for producing a lithium ion battery pack according to the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention; it is apparent that the described embodiments are only some embodiments of the present invention, not all embodiments, and that all other embodiments obtained by persons of ordinary skill in the art without making creative efforts based on the embodiments in the present invention are within the protection scope of the present invention.
As shown in fig. 1, the method for sorting single batteries for producing lithium ion battery packs according to the invention determines the charging current I of the single battery sorting method according to the nominal parameters of the produced lithium ion battery packs 1 Cut-off voltage of charge V 1 Discharge current I 2 And discharge cut-off voltage V 3 Charging current I 1 Charging current I for a battery pack C 1/n, n is the parallel number of single battery cells of the battery pack, and the charging cut-off voltage V 1 The charge cut-off voltage of the battery pack is 1/m, m is the serial number of the single batteries of the battery pack, and the discharge current I 2 1/n of rated discharge current of the battery pack, n is the parallel number of single battery cells of the battery pack, and the discharge cut-off voltage V 3 The method for sorting the single batteries comprises the following steps that 1/m of the lowest discharge voltage of the battery pack is 1/m of the lowest discharge voltage of the battery pack, m is the serial number of the single batteries of the battery pack:
step 1: with charging current I 1 Constant-current charging is carried out on the single batteries to be sorted until the charging cut-off voltage V 1 ；
Step 2: after the battery is placed for 30 to 120 minutes, the voltage of the battery is measured to obtain the constant-current charging static voltage V of the battery 2 ；
Step 3: continue to use I 1 Constant-current and constant-voltage charging of the battery to V by current 1 Charging off current I 0 ；
Step 4: at discharge current I 2 Constant-current discharging of fully charged battery to discharge cut-off voltage V 3 Obtaining the discharge capacity C of the battery 2 ；
Step 5: after 3-120 minutes of rest, measuring the voltage of the battery to obtain the discharge termination rebound voltage V 4 ，
Step 6: with charging current I 3 Constant-current charging is carried out on the discharged battery for t minutes;
step 7: the battery is placed for 2-28 days under the condition of a certain temperature T;
step 8: measuring voltage V of the battery after rest 5 And an internal resistance R;
step 9: according to the discharge capacity C of the battery 2 Constant current charging quiescent voltage V 2 Voltage V of discharge termination rebound 4 Voltage after rest V 5 And the internal resistance R is used for sorting the batteries to be sorted.
In the step 7, the certain temperature T is between normal temperature and 60 ℃.
In the step 9, the single battery to be sorted is sorted by adopting a clustering method based on a variation coefficient and a relative deviation, and the method specifically comprises the following steps:
1) Calculating the discharge capacity C of the single battery to be sorted 2 Average value C of (2) 2a And mean square error C 2s If the coefficient of variation C 2s /C 2a Greater than a first preset threshold epsilon 1 Then remove |C 2 -C 2a The battery with the largest value is recalculated to calculate the remaining battery C 2 Average value C of (2) 2a / And mean square error C 2s / Up to C 2s / /C 2a / Less than or equal to a first preset threshold epsilon 1 Entering step 2);
2) If the relative deviation |C of the discharge capacity of the battery entering this step 2 -C 2a / |/C 2a / Greater than a second preset threshold epsilon 2 Judging that the battery is disqualified in the matching, screening the battery, and entering the rest battery into the step 3);
3) Calculating constant-current charging static voltage V of battery entering the step 2 Average value V of (2) 2a And mean square error V 2s If the coefficient of variation V 2s /V 2a Greater than a third preset threshold epsilon 3 Then screen out |V 2 -V 2a The battery with the largest value is recalculated to calculate the remaining battery V 2 Average value V of (2) 2a / And mean square error V 2s / Up to V 2s / /V 2a / Less than or equal to a third preset threshold epsilon 3 Step 4) is entered;
4) If the battery V of the step is entered 2 Is of the relative deviation |V 2 -V 2a / |/V 2a / Greater than a fourth preset threshold epsilon 4 Judging that the battery is disqualified in the matching, screening the battery, and entering the rest battery into the step 5);
5) Calculating the discharge termination rebound voltage V of the battery entering this step 4 Average value V of (2) 4a And mean square error V 4s If the coefficient of variation V 4s /V 4a Greater than a fifth preset threshold epsilon 5 Then screen out |V 4 -V 4a The battery with the largest value is recalculated to calculate the remaining battery V 4 Average value V of (2) 4a / And mean square error V 4s / Up to V 4s / /V 4a / Less than or equal to a fifth preset threshold epsilon 5 Step 6) is entered;
6) If enter battery |V of this step 4 -V 4a / |/V 4a / Greater than a sixth preset threshold epsilon 6 Judging that the battery is disqualified in the matching, screening the battery, and entering the step 7 by the residual battery;
7) Calculating the voltage V of the battery entering the step 5 Average value V of (2) 5a And mean square error V 5s If the coefficient of variation V 5s /V 5a Greater than a seventh preset thresholdε 7 Then screen out |V 5 -V 5a The battery with the largest value is recalculated to calculate the remaining battery V 5 Average value V of (2) 5a / And mean square error V 5s / Up to V 5s / /V 5a / Less than or equal to a seventh preset threshold epsilon 7 Step 8) is entered;
8) If enter battery |V of this step 5 -V 5a / |/V 5a / Greater than an eighth preset threshold epsilon 8 Judging that the battery is disqualified in the matching, screening the battery, and entering the rest battery into the step 9);
9) Calculating the average value R of the internal resistance R of the battery entering the step a And mean square error R s If the coefficient of variation R s /R a Greater than a ninth preset threshold epsilon 9 Then remove |R-R a The battery with the largest value is used for recalculating the average value R of the residual batteries R a / And mean square error R s / Up to R s / /R a / Less than or equal to a ninth preset threshold epsilon 9 Step 10) is entered;
10 If enter battery |R-R of this step a / |/R a / Greater than a tenth preset threshold epsilon 10 And judging that the batteries are disqualified in battery allocation, screening the batteries, and finishing battery allocation.
In the step 9, the single batteries to be sorted are sorted by adopting a K-means clustering method, a mean shift clustering method or a DBSCAN clustering method.
Examples
The purpose of this example is to group 12 18650 type 2.6Ah ternary lithium ion batteries by using the method of the present invention, and the obtained group battery is used to produce a 3S2P lithium ion battery with a combined structure. The nominal voltage of the lithium ion battery pack is 10.8V, the nominal capacity is 5.2Ah, the charging current is 2A, the working discharging current is 3A, and the working voltage range is 9V-12.6V. According to the actual working parameters of the battery pack, the charging current I when the capacity test is carried out on the batteries to be sorted by the invention can be calculated 1 2A/2=1a, i 2 Discharge current3A/2=1.5a, discharge cut-off voltage V 3 9V/3=3v.
The sorting steps are as follows:
step 1: constant-current charging is carried out on the single batteries to be sorted according to the method 1A, and the single batteries to be sorted are charged to a charging cut-off voltage of 4.2V;
step 2: after 60 minutes of resting, the battery voltage is measured to obtain the battery constant-current charging static voltage V 2 The data are shown in Table 1;
step 3: continuously charging the battery to 4.2V at constant current and constant voltage with 1A current, wherein the charging cut-off current is 52mA;
step 4: constant-current discharging the fully charged battery to a discharge cut-off voltage of 3V by using 1.5A current to obtain the discharge capacity C of the battery 2 The data are shown in Table 1;
step 5: after 60 minutes of rest, the battery voltage is measured to obtain the discharge termination rebound voltage V 4 The data are shown in Table 1,
step 6: constant-current charging is carried out on the discharged battery for 60 minutes by a certain charging current of 1.3A;
step 7: the cell was left to stand at 45℃for 3 days;
step 8: measuring voltage V of the battery after rest 5 And internal resistance R 1 The data are shown in Table 1;
table 1 battery C to be tested 2 、V 2 、V 4 、V 5 And R is 1 Is a measurement of (2)
| Battery serial number | C 2 (mAh) | V 2 (V) | V 4 (V) | V 5 (V) | R 1 (mΩ) |
| 1 | 2580 | 4.057 | 3.179 | 3.697 | 21.3 |
| 2 | 2590 | 4.083 | 3.142 | 3.685 | 20 |
| 3 | 2592 | 4.085 | 3.145 | 3.683 | 20.2 |
| 4 | 2594 | 4.085 | 3.142 | 3.682 | 20.3 |
| 5 | 2597 | 4.085 | 3.145 | 3.682 | 19.4 |
| 6 | 2589 | 4.08 | 3.139 | 3.684 | 19.7 |
| 7 | 2591 | 4.075 | 3.146 | 3.674 | 19.4 |
| 8 | 2592 | 4.081 | 3.141 | 3.682 | 19.2 |
| 9 | 2595 | 4.078 | 3.138 | 3.672 | 19.3 |
| 10 | 2590 | 4.077 | 3.146 | 3.652 | 20.4 |
| 11 | 2592 | 4.079 | 3.143 | 3.683 | 20.1 |
| 12 | 2595 | 4.082 | 3.14 | 3.682 | 19.8 |
Step 9: according to the discharge capacity C of the battery 2 Constant current charging quiescent voltage V 2 Voltage V of discharge termination rebound 4 Voltage after rest V 5 And internal resistance R 1 And sorting the batteries to be sorted. The method comprises the following specific steps:
1) Calculating the discharge capacity C of the single battery to be sorted 2 Average value C of (2) 2a = 2591.4 and mean square error C 2s = 4.1324 taking a first preset threshold ε 1 =0.001, then C 2s /C 2a ＝0.0016>ε 1 . Screen out |C 2 -C 2a The first battery with the largest I value is used for recalculating the residual battery C 2 Average value C of (2) 2a / = 2592.5 and mean square error C 2s / = 2.3884, then C 2s / /C 2a / ＝0.0009<ε 1 Entering step 2);
watch 2|C 2 -C 2a I computation table
2) Taking a second preset threshold epsilon 2 =0.002, calculate |c 2 -C 2a / |/C 2a / The values are shown in Table 2. As can be seen from Table 2, all of the cells |C 2 -C 2a / |/C 2a / Are all smaller than epsilon 2 All cells enter step 3);
watch 3|C 2 -C 2a / |/C 2a / Calculation table
| Battery serial number | C 2 (mAh) | |C 2 -C 2a / |/C 2a / |
| 2 | 2590 | 0.00096 |
| 3 | 2592 | 0.00019 |
| 4 | 2594 | 0.000579 |
| 5 | 2597 | 0.001736 |
| 6 | 2589 | 0.00135 |
| 7 | 2591 | 0.00058 |
| 8 | 2592 | 0.00019 |
| 9 | 2595 | 0.000964 |
| 10 | 2590 | 0.00096 |
| 11 | 2592 | 0.00019 |
| 12 | 2595 | 0.000964 |
| C 2a / | 2592.5 |
3) Calculating constant-current charging static voltage V of 11 batteries entering the step 2 Average value V of (2) 2a = 4.081 and mean square error V 2s = 0.00329 taking a third preset threshold ε 3 =0.001, then V 2s /V 2a ＝0.00097<ε 3 All cells go to step 4);
4) Calculating the |V of 11 batteries entering the step 2 -V 2a |/V 2a The values and results are shown in Table 4, and the fourth preset threshold epsilon is taken 4 As can be seen from table 4, cell No. 7, |v =0.001 2 -V 2a |/V 2a ＝0.00147>ε 4 Judging that the battery is disqualified in matching, screening out the battery, and enabling the rest battery to enter the step 5);
watch 4|V 2 -V 2a |/V 2a Calculation table
| Battery serial number | V 2 (V) | |V 2 -V 2a | | |V 2 -V 2a |/V 2a |
| 2 | 4.083 | 0.002 | 0.00049 |
| 3 | 4.085 | 0.004 | 0.00098 |
| 4 | 4.085 | 0.004 | 0.00098 |
| 5 | 4.085 | 0.004 | 0.00098 |
| 6 | 4.08 | 0.001 | 0.00025 |
| 7 | 4.075 | 0.006 | 0.00147 |
| 8 | 4.081 | 0 | 0 |
| 9 | 4.078 | 0.003 | 0.00074 |
| 10 | 4.077 | 0.004 | 0.00098 |
| 11 | 4.079 | 0.002 | 0.00049 |
| 12 | 4.082 | 0.001 | 0.000245 |
| V 2a | 4.081 |
5) Calculated to obtain the discharge termination rebound voltage V of 10 batteries entering the step 4 Average value V of (2) 4a =3.142 and mean square error V 4s = 0.00255 taking a fifth preset threshold ε 5 =0.001, then V 4s /V 4a ＝0.00081<ε 5 All 10 batteries enter the step 6);
6) Calculating the |V of 10 batteries entering the step 4 -V 4a |/V 4a The values and results are shown in Table 5, and a sixth preset threshold epsilon is taken 6 As can be seen from table 5, all cells |v=0.002 4 -V 4a |/V 4a <ε 6 All 10 batteries enter the step 7);
watch 5|V 4 -V 4a |/V 4a Calculation table
| Battery serial number | V 4 (V) | |V 4 -V 4a | | |V 4 -V 4a |/V 4a |
| 2 | 3.142 | 0 | 0 |
| 3 | 3.145 | 0.003 | 0.000955 |
| 4 | 3.142 | 0 | 0 |
| 5 | 3.145 | 0.003 | 0.000955 |
| 6 | 3.139 | 0.003 | 0.00095 |
| 8 | 3.141 | 0.001 | 0.00032 |
| 9 | 3.138 | 0.004 | 0.00127 |
| 10 | 3.146 | 0.004 | 0.00127 |
| 11 | 3.143 | 0.001 | 0.000318 |
| 12 | 3.14 | 0.002 | 0.00064 |
| V 4a | | 3.1421 |
7) Calculated to get the voltage V of 10 batteries entering the step 5 Average value V of (2) 5a = 3.679 and mean square error V 5s = 0.00952 taking a seventh preset threshold ε 7 =0.001, then V 5s /V 5a ＝0.00259>ε 7 Then calculate |V 5 -V 5a The value of I and remove V 5 -V 5a 10 th battery with maximum I value, and recalculating the remaining battery V 5 Average value V of (2) 5a / = 3.6817 and mean square error V 5s / = 0.00358, then V 5s / /V 5a / ＝0.00097<ε 7, The rest 9 batteries enter the step 8);
watch 6|V 5 -V 5a I value calculation table
8) Calculating and entering 9 batteries |V in the step 5 -V 5a / |/V 5a / The values and results are shown in Table 7, and the eighth preset threshold epsilon is taken 8 As can be seen from table 7, cell 9 |v =0.001 5 -V 5a / |/V 5a / ＝0.00272>ε 8 Judging that the battery is disqualified in matching, screening out the battery, and enabling the rest 8 batteries to enter the step 9);
watch 7|V 5 -V 5a / |/V 5a / Value calculation table
| Battery serial number | V 5 (V) | |V 5 -V 5a / |/V 5a / |
| 2 | 3.685 | 0.000815 |
| 3 | 3.683 | 0.000272 |
| 4 | 3.682 | 0 |
| 5 | 3.682 | 0 |
| 6 | 3.684 | 0.000543 |
| 8 | 3.682 | 0 |
| 9 | 3.672 | 0.00272 |
| 11 | 3.683 | 0.000272 |
| 12 | 3.682 | 0 |
| V 5a / | 3.6817 |
9) Calculating the internal resistance R of 8 batteries entering the step 1 Average value R of (2) 1a =19.84 and mean square error R 1s = 0.38419 taking a ninth preset threshold ε 9 =0.02, then R 1s /R 1a ＝0.01937<ε 9 Step 10), 8 batteries enter the step;
10 Calculating 8 batteries |R-R entering the step a |/R 5a The values and results are shown in Table 8, and the tenth preset threshold epsilon is taken 10 As can be seen from table 8, all 8 cells |r-r=0.03 a |/R a <ε 10 And judging that the remaining 8 electric cores all meet the requirement of the battery sorting and grouping, and finishing the battery sorting and grouping. And 6 cells can be selected from the 8 cells for producing the 3S2P lithium ion battery pack.
Table 8|R-R a |/R 1a Value calculation table
| Battery serial number | R(mΩ) | |R-R a |/R a |
| 2 | 20 | 0.0081 |
| 3 | 20.2 | 0.0181 |
| 4 | 20.3 | 0.0232 |
| 5 | 19.4 | 0.0222 |
| 6 | 19.7 | 0.0071 |
| 8 | 19.2 | 0.0323 |
| 11 | 20.1 | 0.0131 |
| 12 | 19.8 | 0.0020 |
| R a | 19.84 |
The above-described embodiments are only for illustrating the technical spirit and features of the present invention, and it is intended to enable those skilled in the art to understand the content of the present invention and to implement it accordingly, and the scope of the present invention is not limited to the embodiments, i.e. equivalent changes or modifications to the spirit of the present invention are still within the scope of the present invention.
Claims (3)
1. A single battery sorting method for producing lithium ion battery packs is characterized in that charging current I of the single battery sorting method is determined according to nominal parameters of the produced lithium ion battery packs 1 Cut-off voltage of charge V 1 Discharge current I 2 And discharge cut-off voltage V 3 Charging current I 1 Charging current I for a battery pack C 1/n, n is the parallel number of single battery cells of the battery pack, and the charging cut-off voltage V 1 The charge cut-off voltage of the battery pack is 1/m, m is the serial number of the single batteries of the battery pack, and the discharge current I 2 1/n of rated discharge current of the battery pack, n is the parallel number of single battery cells of the battery pack, and the discharge cut-off voltage V 3 The method for sorting the single batteries comprises the following steps that 1/m of the lowest discharge voltage of the battery pack is 1/m of the lowest discharge voltage of the battery pack, m is the serial number of the single batteries of the battery pack:
step 1: with charging current I 1 Constant-current charging is carried out on the single batteries to be sorted until the charging cut-off voltage V 1 ；
Step 2: after being left for 30-120 minutes, is measuredThe battery voltage is obtained to obtain the battery constant current charging static voltage V 2 ；
Step 3: continue to use I 1 Constant-current and constant-voltage charging of the battery to V by current 1 Charging off current I 0 ；
Step 4: at discharge current I 2 Constant-current discharging of fully charged battery to discharge cut-off voltage V 3 Obtaining the discharge capacity C of the battery 2 ；
Step 5: after 3-120 minutes of rest, measuring the voltage of the battery to obtain the discharge termination rebound voltage V 4 ，
Step 6: with charging current I 3 Constant-current charging is carried out on the discharged battery for t minutes;
step 7: the battery is placed for 2-28 days under the condition of a certain temperature T;
step 8: measuring voltage V of the battery after rest 5 And an internal resistance R;
step 9: according to the discharge capacity C of the battery 2 Constant current charging quiescent voltage V 2 Voltage V of discharge termination rebound 4 Voltage after rest V 5 And the internal resistance R is used for sorting the single batteries to be sorted by adopting a clustering method based on a variation coefficient and relative deviation, and the method specifically comprises the following steps:
1) Calculating the discharge capacity C of the single battery to be sorted 2 Average value C of (2) 2a And mean square error C 2s If the coefficient of variation C 2s /C 2a Greater than a first preset threshold epsilon 1 Then remove |C 2 -C 2a The battery with the largest value is recalculated to calculate the remaining battery C 2 Average value C of (2) 2a / And mean square error C 2s / Up to C 2s / /C 2a / Less than or equal to a first preset threshold epsilon 1 Entering step 2);
2) If the relative deviation |C of the discharge capacity of the battery entering this step 2 -C 2a / |/C 2a / Greater than a second preset threshold epsilon 2 Judging that the battery is disqualified in the matching, screening the battery, and entering the rest battery into the step 3);
3) Calculation goes to this stepConstant current charge rest voltage V of flash battery 2 Average value V of (2) 2a And mean square error V 2s If the coefficient of variation V 2s /V 2a Greater than a third preset threshold epsilon 3 Then screen out |V 2 -V 2a The battery with the largest value is recalculated to calculate the remaining battery V 2 Average value V of (2) 2a / And mean square error V 2s / Up to V 2s / /V 2a / Less than or equal to a third preset threshold epsilon 3 Step 4) is entered;
4) If the battery V of the step is entered 2 Is of the relative deviation |V 2 -V 2a / |/V 2a / Greater than a fourth preset threshold epsilon 4 Judging that the battery is disqualified in the matching, screening the battery, and entering the rest battery into the step 5);
5) Calculating the discharge termination rebound voltage V of the battery entering this step 4 Average value V of (2) 4a And mean square error V 4s If the coefficient of variation V 4s /V 4a Greater than a fifth preset threshold epsilon 5 Then screen out |V 4 -V 4a The battery with the largest value is recalculated to calculate the remaining battery V 4 Average value V of (2) 4a / And mean square error V 4s / Up to V 4s / /V 4a / Less than or equal to a fifth preset threshold epsilon 5 Step 6) is entered;
6) If enter battery |V of this step 4 -V 4a / |/V 4a / Greater than a sixth preset threshold epsilon 6 Judging that the battery is disqualified in the matching, screening the battery, and entering the step 7 by the residual battery;
7) Calculating the voltage V of the battery entering the step 5 Average value V of (2) 5a And mean square error V 5s If the coefficient of variation V 5s /V 5a Greater than a seventh preset threshold epsilon 7 Then screen out |V 5 -V 5a The battery with the largest value is recalculated to calculate the remaining battery V 5 Average value V of (2) 5a / And mean square error V 5s / Up to V 5s / /V 5a / Less than or equal to a seventh preset threshold epsilon 7 Step 8) is entered;
8) If enter battery |V of this step 5 -V 5a / |/V 5a / Greater than an eighth preset threshold epsilon 8 Judging that the battery is disqualified in the matching, screening the battery, and entering the rest battery into the step 9);
9) Calculating the average value R of the internal resistance R of the battery entering the step a And mean square error R s If the coefficient of variation R s /R a Greater than a ninth preset threshold epsilon 9 Then remove |R-R a The battery with the largest value is used for recalculating the average value R of the residual batteries R a / And mean square error R s / Up to R s / /R a / Less than or equal to a ninth preset threshold epsilon 9 Step 10) is entered;
10 If enter battery |R-R of this step a / |/R a / Greater than a tenth preset threshold epsilon 10 And judging that the batteries are disqualified in battery allocation, screening the batteries, and finishing battery allocation.
2. The method according to claim 1, wherein in the step 7, the certain temperature T is between room temperature and 60 ℃.
3. The method for sorting the single cells for producing the lithium ion battery pack according to claim 1, wherein in the step 9, the single cells to be sorted are sorted by a K-means clustering method, a mean shift clustering method or a DBSCAN clustering method.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111559764.0A CN114247663B (en) | 2021-12-20 | 2021-12-20 | Single battery sorting method for producing lithium ion battery pack |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111559764.0A CN114247663B (en) | 2021-12-20 | 2021-12-20 | Single battery sorting method for producing lithium ion battery pack |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN114247663A CN114247663A (en) | 2022-03-29 |
| CN114247663B true CN114247663B (en) | 2023-12-15 |
Family
ID=80793025
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111559764.0A Active CN114247663B (en) | 2021-12-20 | 2021-12-20 | Single battery sorting method for producing lithium ion battery pack |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114247663B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116008820B (en) * | 2023-03-24 | 2023-10-10 | 中国汽车技术研究中心有限公司 | Method, device and medium for detecting inconsistency of vehicle battery cells |
Citations (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001281307A (en) * | 2000-03-30 | 2001-10-10 | Sanyo Electric Co Ltd | Battery capacity detecting method |
| JP2003157912A (en) * | 2001-08-13 | 2003-05-30 | Hitachi Maxell Ltd | Method and device for cell capacity detection |
| CN101692506A (en) * | 2009-09-25 | 2010-04-07 | 北京北方专用车新技术发展有限公司 | Active equalization method for lithium ion battery pack in charging state |
| CN101692507A (en) * | 2009-09-25 | 2010-04-07 | 北京北方专用车新技术发展有限公司 | Active equalization method for lithium ion battery pack in state of low current discharge |
| WO2012113221A1 (en) * | 2011-02-23 | 2012-08-30 | 欣旺达电子股份有限公司 | Equalization method and system for discharge of power lithium ion battery pack |
| JP2012209026A (en) * | 2011-03-29 | 2012-10-25 | Panasonic Corp | Method for manufacturing battery pack |
| CN104607395A (en) * | 2013-11-01 | 2015-05-13 | 北汽福田汽车股份有限公司 | lithium ion battery sorting method |
| EP3086386A1 (en) * | 2015-04-22 | 2016-10-26 | Shin-Etsu Chemical Co., Ltd. | Negative electrode active material for non-aqueous electrolyte secondary battery, method of producing the same, non-aqueous electrolyte secondary battery using the negative electrode active material, and method of producing negative electrode material for non-aqueous electrolyte secondary battery |
| CN106602061A (en) * | 2016-12-28 | 2017-04-26 | 天津先众新能源科技股份有限公司 | Preparation method of high-density lithium iron phosphate material |
| CN106824831A (en) * | 2016-12-19 | 2017-06-13 | 金同林 | A kind of manufacture method of the motive-power battery for improving lithium ion battery uniformity |
| CN206383987U (en) * | 2016-12-27 | 2017-08-08 | 天津先众新能源科技股份有限公司 | A kind of lithium ion battery production cart |
| KR20190048849A (en) * | 2017-10-31 | 2019-05-09 | 삼성에스디아이 주식회사 | Battery charging method and battery charging device thereof |
| WO2019237829A1 (en) * | 2018-06-12 | 2019-12-19 | 华为技术有限公司 | Battery system, and method for detecting state of health of battery |
-
2021
- 2021-12-20 CN CN202111559764.0A patent/CN114247663B/en active Active
Patent Citations (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001281307A (en) * | 2000-03-30 | 2001-10-10 | Sanyo Electric Co Ltd | Battery capacity detecting method |
| JP2003157912A (en) * | 2001-08-13 | 2003-05-30 | Hitachi Maxell Ltd | Method and device for cell capacity detection |
| CN101692506A (en) * | 2009-09-25 | 2010-04-07 | 北京北方专用车新技术发展有限公司 | Active equalization method for lithium ion battery pack in charging state |
| CN101692507A (en) * | 2009-09-25 | 2010-04-07 | 北京北方专用车新技术发展有限公司 | Active equalization method for lithium ion battery pack in state of low current discharge |
| WO2012113221A1 (en) * | 2011-02-23 | 2012-08-30 | 欣旺达电子股份有限公司 | Equalization method and system for discharge of power lithium ion battery pack |
| JP2012209026A (en) * | 2011-03-29 | 2012-10-25 | Panasonic Corp | Method for manufacturing battery pack |
| CN104607395A (en) * | 2013-11-01 | 2015-05-13 | 北汽福田汽车股份有限公司 | lithium ion battery sorting method |
| EP3086386A1 (en) * | 2015-04-22 | 2016-10-26 | Shin-Etsu Chemical Co., Ltd. | Negative electrode active material for non-aqueous electrolyte secondary battery, method of producing the same, non-aqueous electrolyte secondary battery using the negative electrode active material, and method of producing negative electrode material for non-aqueous electrolyte secondary battery |
| CN106824831A (en) * | 2016-12-19 | 2017-06-13 | 金同林 | A kind of manufacture method of the motive-power battery for improving lithium ion battery uniformity |
| CN206383987U (en) * | 2016-12-27 | 2017-08-08 | 天津先众新能源科技股份有限公司 | A kind of lithium ion battery production cart |
| CN106602061A (en) * | 2016-12-28 | 2017-04-26 | 天津先众新能源科技股份有限公司 | Preparation method of high-density lithium iron phosphate material |
| KR20190048849A (en) * | 2017-10-31 | 2019-05-09 | 삼성에스디아이 주식회사 | Battery charging method and battery charging device thereof |
| WO2019237829A1 (en) * | 2018-06-12 | 2019-12-19 | 华为技术有限公司 | Battery system, and method for detecting state of health of battery |
Non-Patent Citations (5)
| Title |
|---|
| 动力电池健康因子提取实验研究;熊平;刘翼平;游力;丁永明;;湖北电力(第02期);全文 * |
| 基于K均值法与遗传算法的退役动力电池筛选;杨泓奕;陈家辉;汤志明;;电源技术(第12期);全文 * |
| 基于老化机理分析退役磷酸铁锂电池分选方法;薛金花;陶以彬;杨波;吴福保;孙金磊;;电源技术(第05期);全文 * |
| 锂离子电池串联一致性与电压差的研究;王正;庞佩佩;赵付双;邓耀明;;电池工业(第01期);全文 * |
| 锂离子电池自放电电流检测系统的设计;史永胜;李珏;朱冉;;国外电子测量技术(第11期);全文 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN114247663A (en) | 2022-03-29 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN110165319B (en) | Sorting method for self-discharge performance of high-capacity lithium battery | |
| CN105903692B (en) | Lithium ion battery conformity classification method | |
| CN102544606B (en) | Cluster analysis based lithium battery unit matching method | |
| CN103579700B (en) | A kind of lithium ion battery sorting method for group matching | |
| CN105738830B (en) | Lithium-ion-power cell echelon utilizes analysis method | |
| CN108508365B (en) | Lithium ion battery self-discharge screening method | |
| CN103008261A (en) | Method for sorting degrees of self-discharging of lithium ion batteries | |
| CN109768342B (en) | Matching method of power lead storage batteries | |
| CN105510847A (en) | Method for screening consistency of lithium ion batteries | |
| CN108051751B (en) | Lithium ion power battery sorting method and system | |
| JP2004053598A (en) | Capacity sorting method of secondary cell using specific resistance factor computation of equivalent circuit model copied from impedance spectrum | |
| CN103594742A (en) | Sorting and grouping method for power lead-acid storage battery set | |
| CN108732499B (en) | Method and system for detecting cycle life of lithium ion battery | |
| CN111123120B (en) | Method for measuring self-discharge current of lithium ion battery | |
| CN105280969B (en) | The ferric phosphate lithium cell method for group matching of electric discharge pressure difference between a kind of diminution series battery | |
| CN112379283A (en) | Self-discharge screening method for power battery | |
| CN112103570A (en) | Power battery matching process | |
| CN105728352A (en) | Battery sorting method | |
| CN114247663B (en) | Single battery sorting method for producing lithium ion battery pack | |
| CN101388562B (en) | Fast charging method | |
| CN109116246B (en) | Lead-acid storage battery abuse overdischarge performance evaluation method and capacity recovery method | |
| CN107838057A (en) | A kind of quick method for separating of ternary lithium ion battery | |
| CN108461838B (en) | Method for rapidly screening internal resistance and capacity of battery | |
| CN112379285B (en) | Battery pack self-discharge screening method | |
| CN111883865A (en) | Low-temperature charging method for lithium ion battery |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |