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A method for precise control of electrolyte retention in lithium-ion batteries

A technology of lithium-ion batteries and control methods, which is applied in the field of precise control of electrolyte retention in lithium-ion batteries, can solve the problems of waste of battery electrolyte, excessive gas production of batteries, and unequal loss of electrolyte, etc., and achieve reduction The effect of using amount, reducing production cost, and improving the consistency of electrochemical performance

Active Publication Date: 2021-08-03
台州钱江新能源研究院有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] For cells that adopt the double injection production method, there are two external factors that affect the electrolyte retention. After the first liquid injection is completed, the cell is formed. Since part of the electrolyte volatilizes or is discharged with the gas production during the process, its electrolysis The amount of liquid loss varies, and the quantitative injection of the second liquid injection leads to further deviations in the electrolyte retention of the battery
Excessively high electrolyte retention will lead to side effects such as excessive gas production and reduced safety during use of the battery cell, while too low electrolyte retention will lead to a decrease in the kinetic performance of the cell
Due to the need to ensure the proper use of electrolyte, it is generally chosen to inject a little too much, resulting in excessive waste of electrolyte in some cells
[0004] That is to say, in the research at this stage, one-time liquid injection is generally used to save process operation time, and the impact of excess and small amount on the life of the battery cell is not considered.
Those who focus on the second injection usually only complete the injection step by step on the basis of the first injection, which is only more accurate than the first injection, but the deviation caused by the preparation process cannot be ruled out.
[0005] Aiming at defects such as large errors and complicated processes in the existing technology, Publication No. 105787140A discloses a method for determining the electrolyte retention and injection volume of soft-packed lithium-ion batteries, and accurately calculates the electrolyte injection volume by formulating
Although the calculation result of the formula is very accurate, in the actual liquid injection process, the actual liquid injection volume will change due to environmental changes, process steps and other manipulations

Method used

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  • A method for precise control of electrolyte retention in lithium-ion batteries

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0029] Pre-processing: Select the standard battery, record the weight as M1 after weighing the standard battery, determine the electrolyte retention of the standard battery as m1, bake the battery, and then scan the code for the first time and weigh the battery , record the barcode as Ln, the barcode corresponding to different batteries can be recorded as L1, L2, L3... in turn, record the weight as M2, convert the electrolyte retention of the battery to m3, m3=(M2-M1)+m1;

[0030] One-time variable injection: inject liquid into the battery cell, set the liquid injection volume to m4, m4=80%m3, weigh the battery cell after the liquid injection is completed, record the weight as M3, and then calculate the variable injection volume once as m5 = M3-M2 and inject liquid, then detect the offset value between the liquid injection amount and the liquid injection set amount, when the liquid injection amount exceeds the liquid injection set amount by 2g, squeeze out the excess amount, wh...

Embodiment 2

[0033] Pre-processing: Select the standard battery, record the weight as M1 after weighing the standard battery, determine the electrolyte retention of the standard battery as m1, bake the battery, and then scan the code for the first time and weigh the battery , record the barcode as Ln, the barcode corresponding to different batteries can be recorded as L1, L2, L3... in turn, record the weight as M2, convert the electrolyte retention of the battery to m3, m3=(M2-M1)+m1;

[0034] One-time variable injection: inject liquid into the battery cell, set the liquid injection volume to m4, m4=78%m3, weigh the battery cell after the liquid injection is completed, record the weight as M3, and then calculate the variable injection volume once as m5 = M3-M2 and inject liquid, then detect the offset value between the liquid injection amount and the liquid injection set amount, when the liquid injection amount exceeds the liquid injection set amount by 2g, squeeze out the excess amount, wh...

Embodiment 3

[0037] Pre-processing: Select the standard battery, record the weight as M1 after weighing the standard battery, determine the electrolyte retention of the standard battery as m1, bake the battery, and then scan the code for the first time and weigh the battery , record the barcode as Ln, the barcode corresponding to different batteries can be recorded as L1, L2, L3... in turn, record the weight as M2, convert the electrolyte retention of the battery to m3, m3=(M2-M1)+m1;

[0038]One-time variable injection: inject liquid into the battery cell, set the liquid injection volume to m4, m4=82%m3, weigh the battery cell after the liquid injection is completed, record the weight as M3, and then calculate the variable injection volume once as m5 = M3-M2 and inject liquid, then detect the offset value between the liquid injection amount and the liquid injection set amount, when the liquid injection amount exceeds the liquid injection set amount by 2g, squeeze out the excess amount, whe...

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Abstract

The invention discloses a precise control method for electrolyte retention of a lithium-ion battery, belonging to the technical field of lithium batteries. Lithium-ion battery cells go through pre-treatment, primary variable injection, secondary variable injection and other technological processes. By measuring the weight of the cell, the influence of different electrolyte requirements caused by different coating thickness and surface density is eliminated, and the calculation formula is used. Calculate the corresponding total electrolyte demand, and determine the first injection volume according to a certain same injection ratio. By ensuring the consistency of the total electrolyte demand of a single cell, and eliminating the influence of electrolyte loss during the formation stage, the second injection is adopted. The variable injection method realizes the precise control of the injection volume.

Description

technical field [0001] The invention belongs to the technical field of lithium batteries, and in particular relates to a precise control method for electrolyte retention in lithium-ion batteries. Background technique [0002] The amount of electrolyte in lithium-ion batteries has a great impact on the performance of battery products (such as internal resistance, charge and discharge rate, capacity, cycle time, etc.). In the current production, the quality of the active material of the battery is calculated according to the design parameters of the battery, and then the electrolyte retention is determined. This production method ignores the fluctuation in the quality of the active material of the cell due to the fluctuation of the coating process between each cell. [0003] For cells that adopt the double injection production method, there are two external factors that affect the electrolyte retention. After the first liquid injection is completed, the cell is formed. Since ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H01M50/609H01M10/058H01M50/60
CPCH01M10/058H01M50/60Y02E60/10Y02P70/50
Inventor 张志伟李正斌仇健荣黄相博刘明明孙坤闫振忠
Owner 台州钱江新能源研究院有限公司