LFP lithium ion cell capacity grading and screening 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 screening method and lithium-ion technology, applied in circuits, electrical components, secondary batteries, etc., can solve the problem of low cell consistency, improve cycle performance and safety performance, and ensure consistency and consistency.
Active Publication Date: 2019-03-19
HEFEI GUOXUAN HIGH TECH POWER ENERGY
View PDF4 Cites 11 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
[0005] A kind of LFP lithium-ion cell capacity screening method proposed by the present invention can overcome the technical problem of low consistency of the cells screened in the existing process
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
[0050] A sorting and screening method for 30Ah cells with a square aluminum shell, including the steps of sorting and binning:
[0051] The specific steps are as follows:
[0052] (1) Clean the battery cells on the production line, and conduct visual inspection and screening;
[0053] (2) Put the batteries that pass the appearance screening into the capacity separation tray, scan the tray code and the battery barcode, and put it into the capacity separation cabinet. The temperature of the capacity separation room is controlled at 30±3°C;
[0054] (3) Set aside for 5 minutes;
[0055] (4) Charge with constant current and constant voltage at a certain current, the current is 9000mA, the voltage limit is 3.65V, the current limit is 500 mA, and the time limit is 180min;
[0056] (5) Set aside for 5 minutes;
[0057] (6) Discharge with a certain current, the current is 18500mA, the cut-off voltage is 2.0V, and the time limit is 120min;
[0058] (7) Set aside for 5 minutes;
[...
example 2
[0078] A method for sorting and screening 27Ah batteries with square aluminum shells, including the steps of sorting and binning:
[0079] The specific steps are as follows:
[0080] (1) Clean the battery cells on the production line, and conduct visual inspection and screening;
[0081] (2) Put the batteries that pass the appearance screening into the capacity separation tray, scan the tray code and the battery barcode, and put it into the capacity separation cabinet. The temperature of the capacity separation room is controlled at 30±3°C;
[0082] (3) Set aside for 5 minutes;
[0083] (4) Charge with constant current and constant voltage at a certain current, the current is 6000mA, the voltage limit is 3.65V, the current limit is 500 mA, and the time limit is 180min;
[0084] (5) Set aside for 5 minutes;
[0085] (6) Discharge with a certain current, the current is 18500mA, the cut-off voltage is 2.0V, and the time limit is 70min;
[0086] (7) Set aside for 5 minutes;
...
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 an LFP lithium ion cell capacity grading and screening method, which solves the technical problem of low uniformity of an existing process in cell screening. The method includes steps: subjecting to-be-tested cells to appearance screening, and putting into a capacity grading cabinet at a temperature of 30+ / -3 DEG C; adopting constant current and constant voltage to charge and discharge the to-be-tested cells in sequence until activation of the to-be-tested cells stops; adopting limited voltage for discharging the to-be-tested cells in sequence interruptedly from high current to low current to make the to-be-tested cells in an unloaded state; adopting low current for charging the to-be-tested cells in sequence interruptedly to achieve SOC state uniformity of the to-be-tested cells in 3.0V; detaching the to-be-tested cells from the capacity grading cabinet, measuring OCV3 and OCR3 in 15-24h, and performing capacity screening; measuring OCV4 and OCR4, calculating ak value, testing cell thickness, screening the cells according to the k value and the cell thickness to obtain qualified cells, and outputting for use. By application of limited-voltage low current for charge and discharge, great uniformity of initial states of the cells is guaranteed, and cycle performance and safety of battery packs are improved.
Description
technical field [0001] The invention relates to the technical field of lithium-ion battery manufacturing, in particular to a method for screening LFP lithium-ion batteries by capacity. Background technique [0002] Lithium-ion batteries have become the mainstream choice for automotive power batteries due to their high energy density and long cycle life. As the battery manufacturing process becomes more and more mature, and the competition among various manufacturers becomes more and more fierce, the consistency of the battery combination is especially important for improving product quality and reducing production costs. [0003] Cell consistency, mainly including initial capacity, initial voltage, self-discharge rate, initial internal resistance, fully charged thickness, empty state thickness, cell weight, capacity decay rate, internal resistance growth rate, cell charge and discharge temperature rise, etc. . [0004] At present, in the lithium battery industry, the produ...
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