Lithium-ion battery consistency screening method
A lithium-ion battery and screening method technology, which is applied in the field of lithium-ion battery consistency screening, can solve problems such as long time-consuming, low accuracy, and battery self-discharge, and achieve the goals of reducing differences, high reliability, and improving service life Effect
Active Publication Date: 2018-05-25
SICHUAN CHANGHONG ELECTRIC CO LTD
View PDF8 Cites 0 Cited by
- Summary
- Abstract
- Description
- Claims
- Application Information
AI Technical Summary
Problems solved by technology
They have their own advantages and disadvantages. For example, the voltage method is simple to operate, but does not consider the load change; Poor accuracy due to the influence of polarization internal resistance
[0006] It is impossible to completely avoid dust and impurities in the production process of the battery. Their existence will cause a micro-short circuit inside the battery and cause self-discharge.
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 moreImage
Smart Image Click on the blue labels to locate them in the text.
Smart ImageViewing Examples
Examples
Experimental program
Comparison scheme
Effect test
Embodiment
[0044] The following is a detailed description of the present invention for the consistency screening matching group of a certain brand of lithium iron phosphate battery (3.2V\3.5AH):
[0045] 1. Select 200 single cells, discharge them at a constant current of 0.2C to 2.5V at 25°C±5°C, and put them aside for 1h;
[0046] 2. Charge to 3.2V with a constant current of 0.2C ~ 1C, turn to constant voltage charging until the current drops to 0.05C, and leave it for 1h; use a capacity tester and an internal resistance tester to record the capacity data set q i ,(i=1, 2,...200), internal resistance data set r i (i=1, 2, ... 200)
[0047] 3. Send the sample to 45°C±2°C, 95% environment, and leave it for 7 days; then measure its voltage to obtain v i ,(i=1,2,...200);
[0048] 4. Select the number of clusters as 4, and randomly select 4 members of the sample group as the initial cluster center vector F 1,1 (q 1,1 ,r 1,1 ,v 1,1 ), F 75,1 (q 75,1 ,r 75,1 ,v 75,1 ), F 120,1 (q ...
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 battery testing technology, and discloses a lithium ion battery consistency screening method which effectively reduces difference between single battery cells in a lithium battery pack and prolongs the service life of the whole battery pack. The lithium ion battery consistency screening method comprises the steps of: a, selecting N single lithium ion batteries as a test sample group, carrying out constant-current discharging on each battery in the test sample group until the voltage of the battery reaches a preset final discharging voltage, and then standing for a certain time; b, after carrying out constant-current charging on each battery in the test sample group until the voltage of the battery reaches the preset final charging voltage, carrying out constant-voltage charging, standing for a certain time, and testing and recording a capacity data set qi (i=1, 2,...N) and an internal resistance data set ri (i=1, 2,...N); c, after placing the test sample group in a high-temperature and high-humidity environment for a certain time, testing voltage vi (i=1, 2, ...N) of each battery in the test sample group; and d, carrying out K-mean value clustering and grouping calculation on a vector set Xi (qi, ri, vi), and finishing consistency screening of the sample group according to a calculation result.
Description
technical field [0001] The invention relates to battery testing technology, in particular to a lithium ion battery consistency screening method. Background technique [0002] Due to its high energy storage density, long life, low self-discharge rate, and low environmental pollution, lithium-ion batteries have gradually become the main power source for digital products and new energy vehicles. [0003] The voltage of a single lithium battery is usually only 3.0V ~ 4.0V (nominal voltage is 3.6V), and the capacity is limited. Therefore, in high-power systems such as electric vehicles and electric tools, it is necessary to use dozens or hundreds of lithium batteries. Used in series and parallel in groups. [0004] Due to the limitation of process preparation, even the single cells produced in the same batch will have differences in voltage, capacity, internal resistance and self-discharge rate. If they are used in groups without screening, these differences will seriously redu...
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
Login to View More Patent Type & Authority Patents(China)
IPC IPC(8): B07C5/344
CPCB07C5/344
Inventor 李珣
Owner SICHUAN CHANGHONG ELECTRIC CO LTD