Method for testing porosity of lithium ion battery pole piece
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 and testing method technology, which is applied in the field of testing the porosity of lithium-ion battery pole pieces, can solve the problems affecting the real porosity of pole pieces, quality reduction, serious pollution, etc., to improve test accuracy, reduce deviation, Measuring the effect of low cost
Inactive Publication Date: 2017-05-31
HEFEI GUOXUAN HIGH TECH POWER ENERGY
View PDF10 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
This test method is costly, difficult to operate and seriously polluting
[0004] In addition, domestically, there is a method (CN103134744B) in which pole pieces are immersed in the solution and weighed to calculate the porosity of the pole pieces (CN103134744B). Ignoring the quality reduction caused by the volatilization of the immersion solution after the pole piece is taken out, which affects the true porosity of the pole piece
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
Examples
Experimental program
Comparison scheme
Effect test
Embodiment 1
[0030] (1) Take a rectangular lithium iron phosphate positive pole piece, measure the length, width and thickness of the pole piece, according to V 0 = Length (L) × Width (m) × Thickness (d), get its volume V 0 =3.982×10 -5 m 3 ;
[0031] (2) Hang the pole piece on the electronic spring balance, and read the weight G of the pole piece 0 =0.8124N;
[0032] (3) Put the electrode piece suspended on the electronic spring scale into a container filled with ethylene glycol solution, so that the ethylene glycol is completely immersed in the lithium iron phosphate positive electrode piece. After soaking for 2 hours, read the value F of the electronic spring scale 1 =0.6190N;
[0033] (4) According to the formula ε=1-(G 0 -F 1 ) / ρgV 0 ×100%, the porosity ε=38.52% of the pole piece is obtained.
Embodiment 2
[0035] (1) Take a circular graphite negative electrode, measure the radius and thickness of the electrode, and then according to V 0 = πr 2 ×thickness (d) to get its volume V 0 =1.287×10 -5 m 3 ;
[0036] (2) Hang the pole piece taken on the electronic spring balance, and read the weight G of the pole piece 0 =0.3510N;
[0037] (3) Place the electrode piece suspended on the electronic spring scale in a container filled with distilled water solution, so that the distilled water completely immerses the graphite negative electrode piece, and after soaking for 2 hours, read the value F of the electronic spring scale 1 =0.2698N;
[0038] (4) According to the formula ε=1-(G 0 -F 1 ) / ρgV 0 ×100%, the porosity ε=36.94% of the pole piece is obtained.
[0039] The pole pieces tested in the above examples 1 and 2 were respectively measured for their porosity using the mercury porosimeter method and the cetane soaking quality difference method, and the data comparison is as foll...
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 discloses a method for testing porosity of a lithium ion battery pole piece. The method comprises steps as follows: the lithium ion battery pole piece in a regular shape is taken, and the volume V0 of the lithium ion battery pole piece is measured; the pole piece is suspended on an electronic spring scale, and the weight G0 of the pole piece is obtained; the pole piece suspended on the electronic spring scale is totally immersed in an infiltrating type solution, and a numeric value F1 of the electronic spring scale is read after no less than 2 hours; the porosity epsilon of the pole piece is calculated according to the formula that epsilon is equal to a product obtained by multiplying the difference between 1 and the difference between G0 and F1 by 100%. The testing method has the advantages of being simple to operate, high in testing efficiency, low in testing cost and the like, complicated operation processes of mercury injection apparatus are avoided, pollution of mercury to the environment and harm of mercury to operators are reduced, and porosity test deviation caused by solution volatilization when the piece is taken out for weighing after immersion can be effectively reduced due to the fact that the volume change during immersion of the pole piece is considered in the test process and weight change after liquid absorption of the pole piece is measured in situ.
Description
technical field [0001] The invention belongs to the technical field of lithium ion batteries, and in particular relates to a method for testing the porosity of pole pieces of lithium ion batteries. Background technique [0002] Lithium-ion batteries are regarded as one of the most efficient electrochemical energy storage systems due to their high specific energy, high specific power, and environmental friendliness. Lithium-ion batteries are composed of positive and negative pole pieces and electrolyte, wherein the porosity of the pole piece is the ratio of the total volume of the tiny voids inside the pole piece to the total volume of the pole piece, and the effective porosity is the interconnected tiny voids in the pole piece The ratio of the total volume to the surface volume of the pole piece is an important parameter affecting the electrolyte transmission performance, and the porosity directly reflects the compactness of the material. If the porosity is too large, it wi...
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