CN111766526A - Method for detecting electrochemical polarization impedance of lithium ion battery - Google Patents
Method for detecting electrochemical polarization impedance of lithium ion battery Download PDFInfo
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- CN111766526A CN111766526A CN202010579206.XA CN202010579206A CN111766526A CN 111766526 A CN111766526 A CN 111766526A CN 202010579206 A CN202010579206 A CN 202010579206A CN 111766526 A CN111766526 A CN 111766526A
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- 230000010287 polarization Effects 0.000 title claims abstract description 76
- 238000000034 method Methods 0.000 title claims abstract description 34
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 title claims abstract description 27
- 229910001416 lithium ion Inorganic materials 0.000 title claims abstract description 27
- 238000011084 recovery Methods 0.000 claims abstract description 27
- 238000007599 discharging Methods 0.000 claims abstract description 11
- 238000004321 preservation Methods 0.000 claims abstract description 5
- 238000012360 testing method Methods 0.000 claims description 28
- 239000003990 capacitor Substances 0.000 claims description 3
- 238000012795 verification Methods 0.000 claims description 3
- 238000011160 research Methods 0.000 abstract description 4
- 238000005259 measurement Methods 0.000 description 2
- 238000010998 test method Methods 0.000 description 2
- 238000012935 Averaging Methods 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 230000014509 gene expression Effects 0.000 description 1
- XOFYZVNMUHMLCC-ZPOLXVRWSA-N prednisone Chemical compound O=C1C=C[C@]2(C)[C@H]3C(=O)C[C@](C)([C@@](CC4)(O)C(=O)CO)[C@@H]4[C@@H]3CCC2=C1 XOFYZVNMUHMLCC-ZPOLXVRWSA-N 0.000 description 1
- 230000000630 rising effect Effects 0.000 description 1
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/36—Arrangements for testing, measuring or monitoring the electrical condition of accumulators or electric batteries, e.g. capacity or state of charge [SoC]
- G01R31/389—Measuring internal impedance, internal conductance or related variables
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/36—Arrangements for testing, measuring or monitoring the electrical condition of accumulators or electric batteries, e.g. capacity or state of charge [SoC]
- G01R31/378—Arrangements for testing, measuring or monitoring the electrical condition of accumulators or electric batteries, e.g. capacity or state of charge [SoC] specially adapted for the type of battery or accumulator
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/36—Arrangements for testing, measuring or monitoring the electrical condition of accumulators or electric batteries, e.g. capacity or state of charge [SoC]
- G01R31/382—Arrangements for monitoring battery or accumulator variables, e.g. SoC
- G01R31/3835—Arrangements for monitoring battery or accumulator variables, e.g. SoC involving only voltage measurements
Abstract
The invention provides a method for detecting electrochemical polarization impedance of a lithium ion battery, which comprises the following steps: placing a battery to be detected in a constant temperature environment for heat preservation, then charging and discharging the battery to be detected to a preset SOC state, and standing for a preset first time period; acquiring a U-t recovery curve of the battery in a first time period; and calculating and fitting the U-t recovery curve to obtain the electrochemical polarization impedance of the battery to be tested. The method is simple and easy to implement, is suitable for all battery systems, and has good application prospect in the aspect of lithium ion battery polarization research.
Description
Technical Field
The invention relates to the technical field of lithium ion batteries, in particular to a method for detecting electrochemical polarization impedance of a lithium ion battery.
Background
Lithium ion batteries are receiving more and more attention due to their advantages of long life, high energy, and the like. The polarization impedance is an important parameter for reflecting the severity of the chemical reaction inside the lithium ion battery, and can be used for judging the capacity and the health state of the battery. The polarization impedance is mainly divided into three types, one is ohmic polarization impedance, the second is electrochemical polarization impedance, and the third is concentration polarization impedance, and the three types of polarization impedance are mostly obtained by alternating current impedance (EIS) test at present. Due to the existence of polarization impedance, polarization voltage exists in the battery in the charging and discharging process, if the polarization impedance is too large, the battery can reach a voltage cut-off point too early in the charging and discharging process, so that the charging and discharging capacity of the battery is too low, and the research on the polarization impedance has important significance.
Research workers show that at the moment of power failure of a working battery, polarization potential generated by ohmic polarization impedance occurs instantaneously and is represented as straight-line rising or falling of a voltage recovery curve; the polarization potential generated by the electrochemical polarization impedance appears as a sloping rise or fall of the voltage recovery curve; the concentration polarization impedance produces a polarization potential that appears as a slow, steady voltage recovery curve. Among them, the electrochemical polarization impedance is generally fitted to a complex element model in which a resistance is connected in parallel to an electric double layer capacitance in an ac impedance equivalent circuit model. Based on the thought, the invention provides a novel electrochemical polarization impedance testing method by combining a double electric layer capacitance model, namely a method for detecting electrochemical polarization impedance of a lithium ion battery.
Disclosure of Invention
Based on the technical problems in the background art, the invention provides a method for detecting electrochemical polarization impedance of a lithium ion battery.
The invention provides a method for detecting electrochemical polarization impedance of a lithium ion battery, which comprises the following steps:
s1, placing the battery to be detected in a constant temperature environment for heat preservation, then charging and discharging the battery to be detected to a preset SOC state, and standing for a preset first time period;
s2, acquiring a U-t recovery curve of the battery in a first time period;
and S3, calculating and fitting the U-t recovery curve to obtain the electrochemical polarization impedance of the battery to be tested.
Preferably, in step S3, the method of calculating and fitting the U-t recovery curve includes: and (3) solving logarithm of the difference between the voltage stable value and the real-time voltage value of the battery to be detected in the first time period, then carrying out linear fitting on the logarithm value and the fitting time t intercepted in the first time period to obtain a test curve, and carrying out exponential operation on the intercept of the test curve to obtain the electrochemical polarization resistance Rt of the battery to be detected.
Preferably, the test curve is:
wherein, I is the working current of the battery to be detected before power failure, Rt is the electrochemical polarization impedance, and CdlIs an electric double layer capacitor.
Preferably, in step S3, the fitting time t of the U-t recovery curve is (1S, 300S).
Preferably, in step S1, the first period of time is greater than or equal to 1 h; in step S2, the U-t recovery curve is stepped on for 0.01S or any value in the interval [0.001S, 1S ].
Preferably, in step S1, the battery to be tested is placed in an incubator and kept at a temperature of 25 ℃, or any value within (0, 45] ° c.
Preferably, in step S1, the current range for charging or discharging is 0 ≦ I ≦ 1C.
Preferably, in step S1, the predetermined SOC state is 50% SOC, or 10% SOC or less and 90% SOC or less.
Preferably, the method further comprises the following steps:
s4, performing EIS impedance test on the battery to be detected to obtain an EIS impedance spectrogram, and performing fitting analysis to obtain impedance values generated by each polarization;
s5, comparing the electrochemical polarization impedance obtained in the step S3 with the impedance value obtained in the step S4 for verification.
Preferably, the EIS test mode in step S4 adopts a voltage disturbance mode or a current disturbance mode, and when the voltage disturbance mode is adopted, 5mv voltage disturbance is adopted.
The invention provides a method for detecting electrochemical polarization impedance of a lithium ion battery, which is characterized in that a voltage recovery curve of the lithium ion battery after charging or discharging is taken as a reference, an electrochemical polarization impedance value is obtained through calculation and fitting, and the value is close to a result of electrochemical polarization resistance testing of alternating current impedance (EIS), namely the method can accurately detect the electrochemical polarization impedance of the lithium ion battery. The method is simple and easy to implement, is suitable for all battery systems, and has good application prospect in the aspect of lithium ion battery polarization research.
Drawings
FIG. 1 is a flow chart of a method for detecting electrochemical polarization impedance of a lithium ion battery according to the present invention;
FIG. 2 is a graph of a test of example 1;
FIG. 3 is a graph of the test of example 2.
Detailed Description
Referring to fig. 1, the method for detecting electrochemical polarization impedance of a lithium ion battery provided by the invention comprises the following steps.
S1, placing the battery to be detected in a constant temperature environment for heat preservation, then charging and discharging the battery to be detected to a preset SOC state, and standing for a preset first time period. In the step, the charging or discharging current range is more than or equal to 0 and less than or equal to 1C; the preset SOC state is more than or equal to 10% and less than or equal to 90%, and specifically, the SOC state of 50% can be selected.
Specifically, in this embodiment, the battery to be tested is placed in an incubator for heat preservation, and the temperature of the incubator can be set to any value within (0, 45] ° c, specifically to 25 ℃.
And S2, acquiring a U-t recovery curve of the battery in the first time period.
Specifically, in the present embodiment, the first time period is greater than or equal to 1 h; in step S2, the U-t recovery curve is stepped on for 0.01S or any value in the interval [0.001S, 1S ] to ensure the accuracy of the U-t recovery curve.
And S3, calculating and fitting the U-t recovery curve to obtain the electrochemical polarization impedance of the battery to be tested. Specifically, in this step, the fitting time t range of the U-t recovery curve is (1s,300 s) ]. wherein the length of the first time period is long enough to obtain the voltage plateau value, the voltage plateau value is a value at which the voltage recovers to no longer change during the voltage recovery period (i.e., the first time period), and specifically, the real-time voltage value in the last time period, for example, within 1min during the first time period may be obtained by averaging.
In step S3 of the present embodiment, a method of calculating and fitting the U-t recovery curve is: and (3) solving logarithm of the difference between the voltage stable value and the real-time voltage value of the battery to be detected in the first time period, then carrying out linear fitting on the logarithm value and the fitting time t intercepted in the first time period to obtain a test curve, and carrying out exponential operation on the intercept of the test curve to obtain the electrochemical polarization resistance Rt of the battery to be detected.
Specifically, the potential difference caused by ohmic polarization and electrochemical polarization after the battery to be detected is powered off is Δ E (t) ═ I (Rs + Rt) ═ I Rs + [ Δ Es ] (t) (1)
Wherein I is the working current of the battery before power failure, Rs is ohmic polarization resistance, and Rt is electrochemical polarization resistance;
the following differential expressions are defined according to the capacitance in the electric double layer capacitance model, namely:
Integrating the above formula to obtain
ΔE(∞)＝IRs+IRt
Mixing lg [ Delta E (∞) -Delta E (t)]T is plotted and linear fitting is performed to obtain a test curve as:
the intercept A ═ lg (IR) is then obtainedt) Then, then
And S4, performing EIS impedance test on the battery to be detected to obtain an EIS impedance spectrogram, and performing fitting analysis to obtain impedance values generated by each polarization. In the specific implementation, in the step, the EIS test mode adopts a voltage disturbance mode or a current disturbance mode, and the voltage disturbance mode adopts 5mv voltage disturbance.
S5, comparing the electrochemical polarization impedance obtained in the step S3 with the impedance value obtained in the step S4 for verification.
The invention is further explained below with reference to two specific examples.
Example 1: electrochemical polarization resistance test of ternary full cell system 1C charged to 50% SOC
And S1, placing the battery to be detected in a constant temperature box at 25 ℃, and charging the battery to 50% of SOC at 1C.
And S2, standing for 1h, and acquiring a U-t recovery curve of the battery within the time, wherein the treading time is 0.01S.
S3, taking the average value of the voltage of the last 1min in the standing process as E (∞), making a difference with the real-time voltage value in the standing process for 1h, and taking the logarithm as a test curve, namely:
and (3) selecting a voltage logarithm value within 1-300 s and performing linear fitting on the voltage logarithm value and time to obtain an intercept, namely: lg (IR)t) And after operation, the electrochemical polarization resistance Rt is obtained.
And S4, carrying out alternating current impedance (EIS) test on the battery to be detected in the same state, and carrying out fitting analysis to obtain impedance values generated by each polarization.
S5, comparing the electrochemical polarization impedance obtained in step S3 with the impedance value obtained in step S4, and verifying the comparison, the details are shown in table 1 below.
Table 1: table for recording impedance values obtained in two measurement modes in example 1
The calculation formula of the relative deviation is as follows: o*＝|Rt-REIS|/R EIS100%, relative deviation less than 10%, the difference between the two polarization impedance test methods can be considered negligible.
As can be seen from the above data, the electrochemical polarization resistance value measured in step S3 is closer to the ac impedance EIS test result in step S4, and the relative deviation is about 4.43%, so that the present embodiment 1 can accurately measure the electrochemical polarization resistance of the battery by using the linear fitting of the voltage recovery curve.
Example 2: electrochemical polarization resistance test of ternary positive electrode half-cell system when charging to 50% SOC at 0.1C
And S1, placing the battery to be detected in a constant temperature box at 25 ℃, and charging to 50% SOC at 0.1 ℃.
And S2, standing for 1h, and acquiring a U-t recovery curve of the battery within the time, wherein the treading time is 0.01S.
S3, selecting the voltage average value of the last 1min in the standing process as E (∞), making a difference with each real-time voltage value in the standing process for 1h, and taking the logarithm as a test curve, namely:
and (3) selecting a voltage logarithm value within 1-300 s and performing linear fitting on the voltage logarithm value and time to obtain an intercept, namely: lg (IR)t) And obtaining the polarization resistance Rt after operation.
And S4, carrying out alternating current impedance (EIS) test on the battery to be detected in the same state, and carrying out fitting analysis to obtain impedance values generated by each polarization.
S5, comparing the electrochemical polarization impedance obtained in step S3 with the impedance value obtained in step S4, and verifying the comparison, as shown in table 2 below.
Table 1: example 2 resistance value record table obtained by two measurement modes
The calculation formula of the relative deviation is as follows: o*＝|Rt-REIS|/R EIS100%, relative deviation less than 10%, the difference between the two polarization impedance test methods can be considered negligible.
The data show that the electrochemical polarization impedance value measured by the method is closer to the alternating current impedance EIS test result, and the relative deviation is about 8.72 percent, so that the electrochemical polarization resistance of the battery can be accurately measured by linear fitting of a voltage recovery curve.
The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be considered to be within the technical scope of the present invention, and the technical solutions and the inventive concepts thereof according to the present invention are equivalent to or changed within the technical scope of the present invention.
Claims (10)
1. A method for detecting electrochemical polarization impedance of a lithium ion battery is characterized by comprising the following steps:
s1, placing the battery to be detected in a constant temperature environment for heat preservation, then charging and discharging the battery to be detected to a preset SOC state, and standing for a preset first time period;
s2, acquiring a U-t recovery curve of the battery in a first time period;
and S3, calculating and fitting the U-t recovery curve to obtain the electrochemical polarization impedance of the battery to be tested.
2. The method for detecting electrochemical polarization impedance of a lithium ion battery according to claim 1, wherein in step S3, the method for calculating and fitting the U-t recovery curve comprises: and (3) solving logarithm of the difference between the voltage stable value and the real-time voltage value of the battery to be detected in the first time period, then carrying out linear fitting on the logarithm value and the fitting time t intercepted in the first time period to obtain a test curve, and carrying out exponential operation on the intercept of the test curve to obtain the electrochemical polarization resistance Rt of the battery to be detected.
3. The method for detecting electrochemical polarization impedance of a lithium ion battery according to claim 2, wherein the test curve is as follows:
wherein, I is the working current of the battery to be detected before power failure, and Rt is the electrochemical polarization impedance; cdlIs an electric double layer capacitor.
4. The method for detecting electrochemical polarization impedance of lithium ion battery according to claim 2, wherein in step S3, the fitting time t of the U-t recovery curve is (1S, 300S).
5. The method for detecting electrochemical polarization impedance of lithium ion battery according to claim 1, wherein in step S1, the first period of time is greater than or equal to 1 h; in step S2, the U-t recovery curve is stepped on for 0.01S or any value in the interval [0.001S, 1S ].
6. The method for detecting electrochemical polarization impedance of a lithium ion battery according to claim 1, wherein in step S1, the battery to be detected is placed in an incubator and kept at a temperature of 25 ℃ or any value within (0, 45] ° c.
7. The method for detecting electrochemical polarization impedance of a lithium ion battery according to claim 1, wherein in step S1, the current range for charging or discharging is 0 ≦ I ≦ 1C.
8. The method for detecting electrochemical polarization impedance of lithium ion battery as claimed in claim 1, wherein in step S1, the predetermined SOC state is 50% SOC, or 10% SOC 90%.
9. The method for detecting electrochemical polarization impedance of a lithium ion battery according to any one of claims 1 to 8, further comprising the steps of:
s4, performing EIS impedance test on the battery to be detected to obtain an EIS impedance spectrogram, and performing fitting analysis to obtain impedance values generated by each polarization;
s5, comparing the electrochemical polarization impedance obtained in the step S3 with the impedance value obtained in the step S4 for verification.
10. The method for detecting electrochemical polarization impedance of a lithium ion battery according to claim 9, wherein the EIS test mode in step S4 employs a voltage perturbation mode or a current perturbation mode, and a voltage perturbation mode employs 5mv voltage perturbation.
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112731181A (en) * | 2020-12-30 | 2021-04-30 | 哈尔滨工业大学（威海） | Lithium ion battery impedance model based on electrochemical principle |
| TWI785683B (en) * | 2021-07-14 | 2022-12-01 | 國立臺北科技大學 | Battery rapid screening method and battery rapid screening system |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109752663A (en) * | 2017-11-01 | 2019-05-14 | 微宏动力系统（湖州）有限公司 | A kind of measurement method of the internal resistance of cell |
| CN109856557A (en) * | 2019-01-21 | 2019-06-07 | 合肥国轩高科动力能源有限公司 | A kind of on-line monitoring lithium ion battery electrochemical impedance test method |
| CN109991553A (en) * | 2017-12-29 | 2019-07-09 | 微宏动力系统（湖州）有限公司 | A kind of evaluation method of battery SOC |
| CN110118942A (en) * | 2019-05-22 | 2019-08-13 | 北京科技大学 | A kind of detection method of lithium battery chemical polarization impedance |
-
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- 2020-06-23 CN CN202010579206.XA patent/CN111766526A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109752663A (en) * | 2017-11-01 | 2019-05-14 | 微宏动力系统（湖州）有限公司 | A kind of measurement method of the internal resistance of cell |
| CN109991553A (en) * | 2017-12-29 | 2019-07-09 | 微宏动力系统（湖州）有限公司 | A kind of evaluation method of battery SOC |
| CN109856557A (en) * | 2019-01-21 | 2019-06-07 | 合肥国轩高科动力能源有限公司 | A kind of on-line monitoring lithium ion battery electrochemical impedance test method |
| CN110118942A (en) * | 2019-05-22 | 2019-08-13 | 北京科技大学 | A kind of detection method of lithium battery chemical polarization impedance |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112731181A (en) * | 2020-12-30 | 2021-04-30 | 哈尔滨工业大学（威海） | Lithium ion battery impedance model based on electrochemical principle |
| TWI785683B (en) * | 2021-07-14 | 2022-12-01 | 國立臺北科技大學 | Battery rapid screening method and battery rapid screening system |
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