Secondary Battery Electrode Assembly Partial Pressing Method
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Solution Overview
Problem
The electrolyte in secondary batteries is not fully absorbed into the electrode assembly due to the bonding force between the electrode and separator, limiting the improvement in electrode assembly performance.
Innovation Solution
A method involving the formation of a nonbonding portion on the interface between the electrode and separator, achieved by partially pressing the electrode assembly with a pattern roller to create a bonding and nonbonding area, allowing better electrolyte impregnation and subsequent bonding of the nonbonding portion during the manufacturing process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If the electrode and separator are fully bonded together, then the structural stability is improved, but the electrolyte impregnation is hindered due to resistance at the interface
Solution Approach 1:
The interface between electrode and separator is designed with non-uniform bonding characteristics. Specifically, the bonding force varies at different locations, creating regions with stronger bonding and regions with weaker bonding. This local variation allows the interface to simultaneously provide structural stability in bonded regions while permitting electrolyte penetration in non-bonded regions, thereby resolving the contradiction between structural integrity and electrolyte impregnation.
2Strength
If bonding force between electrode and separator is increased, then the interface strength is improved, but electrolyte absorption is reduced due to resistance
Solution Approach 1:
The bonding force between electrode and separator is designed to vary spatially rather than being uniform. Regions with higher bonding force provide structural strength, while regions with lower bonding force allow electrolyte absorption. This local differentiation of bonding characteristics enables the interface to simultaneously achieve both high strength and good electrolyte absorption without compromising either property.
3Ease of manufacture
If the interface between electrode and separator is fully bonded, then manufacturing simplicity is maintained, but unreacted areas remain during charge and discharge
Solution Approach 1:
The interface bonding is designed with spatially varying characteristics, creating a pattern of bonded and non-bonded regions. This local quality variation allows the manufacturing process to remain relatively simple while the resulting structure eliminates unreacted areas during charge-discharge cycles. The non-uniform bonding ensures better electrolyte distribution and reaction uniformity across the electrode surface, improving overall battery performance without significantly complicating the manufacturing process.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This method enhances electrolyte impregnation and improves the charging and discharging efficiency of the secondary battery by eliminating unreacted areas, leading to improved electrode assembly performance.
Implementation Method 1
a second process (S20) of partially pressing the incomplete electrode assembly to pattern-bond an interface between the electrode and the separator
Implementation Method 2
the electrolyte is permeated into nonbonding portion of the interface between the electrode and the separator and impregnated up to the inside of the electrode assembly
Implementation Method 3
the electrolyte is permeated into nonbonding portion of the interface between the electrode and the separator and impregnated up to the inside of the electrode assembly
Implementation Method 4
a sixth process (S60) of heating and pressing an entire surface of the secondary battery to bond the nonbonding portion of the interface between the electrode and the separator
Implementation Method 5
a sixth process (S60) of heating and pressing an entire surface of the secondary battery to bond the nonbonding portion of the interface between the electrode and the separator
Data Source
AI summary
The present invention relates to a method for manufacturing a secondary battery. The method comprises: a first process (S10) of manufacturing an incomplete electrode assembly; a second process (S20) of partially pressing the incomplete electrode assembly to manufacture a complete electrode assembly in which a bonding portion and a nonbonding portion coexist; a third process (S30) of accommodating the complete electrode assembly into a case; a fourth process (S40) of injecting an electrolyte through an opening of the case to impregnate the electrolyte into the electrode assembly; a fifth process (S50) of sealing an unsealed surface in which the opening of the case is formed to manufacture a secondary battery; and a sixth process (S60) of heating and pressing an entire surface of the secondary battery to bond the nonbonding portion of the interface between the electrode and the separator.