Lithium ion battery electrochemical impedance online monitoring testing method
What is Al technical title?
Al technical title is built by PatSnap Al team. It summarizes the technical point description of the patent document.
A lithium-ion battery, impedance testing technology, applied in the direction of measuring electricity, measuring devices, measuring electrical variables, etc., can solve the problem that the impedance test cannot be completed online
Active Publication Date: 2019-06-07
HEFEI GUOXUAN HIGH TECH POWER ENERGY
View PDF8 Cites 15 Cited by
Summary
Abstract
Description
Claims
Application Information
AI Technical Summary
This helps you quickly interpret patents by identifying the three key elements:
Problems solved by technology
Method used
Benefits of technology
Problems solved by technology
[0004] The present invention proposes an on-line monitoring lithium-ion battery electrochemical impedance test method, which can solve the technical problem that the existing test method cannot complete the impedance test on-line
Method used
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more
Image
Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
Click on the blue label to locate the original text in one second.
Reading with bidirectional positioning of images and text.
Smart Image
Examples
Experimental program
Comparison scheme
Effect test
example 1
[0038] Example 1: When the ternary laminated full battery is 50% SOC, the electrochemical impedance test of the direct current method:
[0039] (1) Place the full battery to be studied in an incubator at 25°C, charge it to 50% SOC, and leave it for 1 hour;
[0040] (2) Perform AC impedance (EIS) test on the battery to be tested on the electrochemical workstation, voltage disturbance, disturbance frequency is 5mv, obtain its EIS impedance spectrum, and fitting analysis obtains the impedance value produced by each polarization; Wherein, such as figure 2 As shown, the frequency time at the inflection point of Rs+Rf+Rct is recorded as t 1 ;
[0041] The EIS fitting data is as follows:
[0042] SOC / %
R s / Ω
R f / Ω
R ct / Ω
R s +R f +R ct / Ω
f / Hz
t 1 / s
50
0.200
0.093
0.347
0.640
2.15
0.464
[0043] (3) Connect the battery after the EIS impedance test to a high-precision test cabinet, and perform differen...
example 2
[0053] Example 2: When the SOC of the ternary positive half-cell is 50%, the electrochemical impedance test of the direct current method
[0054] (1) Place the positive half-cell to be studied in a 25°C incubator, charge it to 50% SOC, and leave it for 1 hour;
[0055] (2) Conduct AC impedance (EIS) test on the electrochemical workstation, voltage disturbance, disturbance frequency is 5mv, obtain its EIS impedance spectrum, and fit analysis to obtain the impedance value generated by each polarization. Among them, R s +R f +R ct The frequency time at the inflection point is recorded as t 1 ;Such as Figure 6 shown.
[0056] The EIS fitting data is as follows:
[0057]
[0058]
[0059] (3) Connect the battery after the EIS impedance test to a high-precision test cabinet, and perform different current pulses on it, the pulse current I=0.2c, 0.4c, 0.6c, 0.8c, 1c, and the pulse time is shown in the EIS impedance spectrum R s +R f +R ct The frequency time at the inf...
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more
PUM
Login to view more
Abstract
The invention relates to a lithium ion battery electrochemical impedance online monitoring testing method. With the method adopted, the technical problem that an existing testing method cannot complete electrochemical impedance testing online can be solved. The method of the invention includes the following steps that: S100, a battery to be tested is arranged in a constant-temperature cabinet, andthe battery to be tested is charged to be in a certain SOC; S200, electrochemical impedance spectroscopy (EIS) testing is performed on the battery to be tested, and impedance values generated by eachpolarization are obtained through analysis; 300, the battery which has been subjected to the EIS testing is connected with a high-precision test cabinet, and current pulses of different gradients areapplied to the battery; and S400, the pending voltage of the battery before the pulse of certain pulse current I is recorded as U0, and the voltage of the battery after a pulse t 2 is recorded as Ut,and deltaU=U0-Ut, and deltaU and pulse current I under different pulse current are selected, so that graphing can be performed, linear fitting is performed, and a slope, namely the impedance value ofDCR testing, is obtained. According to the method of the invention, a direct current method and an alternating current method are combined; the on-line monitoring of the electrochemical impedance change of the battery can be realized through the direct-current impedance test of small-rate current pulses. The method has the advantages of simple experimental process and high practicability.
Description
technical field [0001] The invention relates to the technical field of lithium-ion batteries, in particular to an electrochemical impedance testing method for on-line monitoring of lithium-ion batteries. Background technique [0002] Internal resistance is a very important performance index of the battery, which has an important impact on the fast charging, heat generation and aging of the battery. At present, the methods commonly used to test the internal resistance of the battery include the direct current method (DCR) and the alternating current method (EIS). Among them, the DC method usually discharges the battery at a high rate of 3C or 5C, and then obtains the impedance of the battery within the pulse time according to the ratio between the voltage change value and the pulse current. The AC method is to perturb the battery with a small signal through the electrochemical workstation, and obtain the impedance spectrum of the battery while maintaining the internal stabil...
Claims
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more
Application Information
Patent Timeline
Application Date:The date an application was filed.
Publication Date:The date a patent or application was officially published.
First Publication Date:The earliest publication date of a patent with the same application number.
Issue Date:Publication date of the patent grant document.
PCT Entry Date:The Entry date of PCT National Phase.
Estimated Expiry Date:The statutory expiry date of a patent right according to the Patent Law, and it is the longest term of protection that the patent right can achieve without the termination of the patent right due to other reasons(Term extension factor has been taken into account ).
Invalid Date:Actual expiry date is based on effective date or publication date of legal transaction data of invalid patent.
Login to view more 
Login to view more