Looking for breakthrough ideas for innovation challenges? Try Patsnap Eureka!

Impedance test method for lithium separation detection of lithium ion battery

A lithium-ion battery, impedance testing technology, applied in the direction of measuring electricity, measuring devices, measuring electrical variables, etc., can solve the problems of battery follow-up testing that destroys the integrity of the battery, and the monitoring of lithium behavior that cannot be analyzed, so as to prevent the loss of active materials and The effect of interface degradation, improved service life, and convenient use

Active Publication Date: 2021-03-05
BEIJING INSTITUTE OF TECHNOLOGYGY
View PDF10 Cites 10 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Even though the above methods have wide applicability in the research of lithium-ion batteries, these two detection methods are post-detection methods in the process of lithium analysis, which cannot effectively monitor the lithium analysis behavior of the negative electrode of the battery in real time.
At the same time, when using a scanning electron microscope for detection, it is also necessary to disassemble the battery and take out the electrode sheet for sample preparation, which will destroy the integrity of the battery and the subsequent testing of the battery

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
  • Impedance test method for lithium separation detection of lithium ion battery
  • Impedance test method for lithium separation detection of lithium ion battery

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0036] Example 1 Determining whether the negative electrode has lithium-analysis behavior under the lithium-graphite (Li-Graphite) half-cell system

[0037] (1) Production of the reference electrode: Select an enamelled copper wire with a diameter of 130 μm, remove the polymer coating with a suitable length at both ends, wind one end with a 30 μm lithium sheet with a suitable length, and bend it into a ring after wrapping lithium , the other end does not process;

[0038](2) Li-Graphite three-electrode half-cell assembly: the graphite negative electrode uses mesocarbon microspheres (MCMB), according to the ratio of MCMB: conductive carbon black (Supper P): polyvinylidene fluoride (PVDF) = 8:1:1 Prepare a slurry in a certain amount of N-methylpyrrolidone and mix it evenly. The slurry is coated on a copper foil with a scraper and dried in a blast dryer for 24 hours. A graphite negative electrode circle with a diameter of 13mm is punched by a punching machine. Shaped pole piece;...

Embodiment 2

[0041] Lithium analysis behavior in embodiment 2 full battery

[0042] (1) Production of the reference electrode: Select an enamelled copper wire with a diameter of 130 μm, remove the polymer coating with a suitable length at both ends, wind one end with a 30 μm lithium sheet with a suitable length, and bend it into a ring after wrapping lithium , the other end does not process;

[0043] (2) Graphite negative electrode full battery assembly: choose ternary material (NCM) as the positive electrode material, and the coated surface capacity is 2mA h cm -2 The positive pole piece was punched into a disc with a diameter of 13mm after being dried in a blast drying oven. The graphite negative electrode is prepared according to the proportion of the slurry and then scraped to obtain a surface capacity of 0.6mA h cm -2 The negative pole piece is punched into a disc with a diameter of 13mm after being dried in a blast drying oven. The reference electrode is placed between the positiv...

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

No PUM Login to View More

Abstract

The invention belongs to the technical field of lithium ion batteries, and relates to an impedance test method for lithium precipitation detection of a lithium ion battery. An existing characterization method is generally implemented after a large amount of lithium is separated out of a battery, and information of a lithium separation generation node is difficult to obtain. The invention providesan impedance test method; the principle that the total impedance of the surface of a negative electrode is reduced when a lithium precipitation behavior occurs is utilized, and a node where lithium precipitation occurs is judged through impedance monitoring. A pulse type charging program is applied to a battery, lithium metal is adopted as a reference electrode to construct a three-electrode battery system, the change of the potential difference of the surface of the negative electrode relative to the reference electrode along with the pulse and relaxation of the battery is monitored, and theratio of the potential difference to the added charging current reflects the total impedance of the surface of the negative electrode. An inflection point of which the total impedance is reduced alongwith the charging depth is observed as a starting point of lithium precipitation, and whether a lithium precipitation behavior occurs or not is judged. The test process is simple, convenient and rapid, and the charging depth when lithium precipitation occurs under different charging conditions can be obtained.

Description

technical field [0001] The invention belongs to the technical field of lithium-ion batteries. By introducing a reference electrode into the lithium-ion battery, monitoring the impedance change of the negative electrode of the battery and monitoring whether the lithium-ion battery decomposes without dismantling, the lithium-ion battery is prevented from excessively decomposing lithium. Background technique [0002] With the reduction of fossil energy and the continuous development of new energy forms, traditional fuel vehicles powered by petroleum are gradually transforming into clean and reliable new energy vehicles powered by electricity. In new energy vehicles, the battery as the core of power is the key to realizing the transition of new energy vehicles. Thanks to the stability and long cycle life of lithium-ion batteries, new energy vehicles usually use lithium-ion batteries as their energy source. However, in recent years, safety accidents of some new energy vehicles a...

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
no application Login to View More
Patent Type & Authority Applications(China)
IPC IPC(8): G01R31/389G01R31/385
CPCG01R31/389G01R31/385
Inventor 黄佳琦徐磊闫崇许睿
Owner BEIJING INSTITUTE OF TECHNOLOGYGY
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Patsnap Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Patsnap Eureka Blog
Learn More
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic, Popular Technical Reports.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap|About US| Contact US: help@patsnap.com