Secondary Battery Separator Joint Segmentation for Electrolyte Refilling
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Solution Overview
Problem
Existing non-aqueous electrolyte secondary batteries do not consider refilling of the electrolytic solution or preventing separator breakage at the joint parts, leading to battery performance deterioration and reduced operational life.
Innovation Solution
A secondary battery design with multiple joint parts for the separator to exterior members and a holding part between these joints, where the sum of joint part perimeters is longer than the perimeter of the minimum enclosing rectangle, allowing refilling of electrolyte solution and enhancing strength against tensile forces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If the outer peripheral portion of the separator is joined with the exterior members to prevent displacement of the stacked electrode assembly, then the structural stability is improved, but the separator becomes thinner at the joint parts making it prone to breakage
Solution Approach 1:
The continuous joint part is divided into multiple separate joint parts arranged at different positions around the stacked electrode assembly. This segmentation allows the electrolytic solution to penetrate through the gaps between joint parts and refill the separator, preventing breakage while maintaining structural stability through distributed bonding points
Solution Approach 2:
The joint parts are designed with specific perimeter dimensions and spacing relationships (sum of perimeters longer than perimeter of minimum enclosing rectangle) to pre-establish channels for electrolytic solution penetration. This preliminary structural design enables the separator to be refilled before breakage occurs, preventing the harmful effect of thinning
2Stability of the object's composition
If the separator is joined continuously with the exterior members to prevent displacement, then the structural stability is improved, but refilling of the stacked electrode assembly with electrolytic solution becomes difficult
Solution Approach 1:
The continuous joint structure is segmented into multiple discrete joint parts with gaps between them. These gaps create penetration paths that allow electrolytic solution to reach the separator internally, enabling refilling operation while the distributed joint parts collectively maintain structural stability
Solution Approach 2:
The gaps between joint parts serve as intermediary channels that facilitate the entry of electrolytic solution into the stacked electrode assembly. These intermediary spaces mediate between the external electrolyte reservoir and the internal separator, enabling refilling without compromising the overall structural integrity provided by the joint parts
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 design enables the maintenance of battery performance over long-term use by allowing electrolyte refilling and preventing separator breakage, thus extending the battery's operational life.
Implementation Method 1
There is known a technique for fusion bonding an outer peripheral portion of the separator with the seal portions of the aluminum laminate sheets
Data Source
AI summary
The present invention relates to a secondary battery in which a stacked electrode assembly having a cathode, an anode and a separator is accommodated together with an electrolytic solution between exterior members. In the present invention, the secondary battery has a plurality of joint parts at which the outer peripheral portion of the separator is joined with the exterior members and a holding part formed at least between the joint parts so as to hold therein the electrolytic solution, wherein a sum of perimeters of the joint parts is longer than a perimeter of a rectangle of minimum area enclosing therein all of the joint parts. In this configuration, it is possible to refill the stacked electrode assembly with the electrolytic solution and protect the joint parts from breakage while preventing displacement of the stacked electrode assembly in the secondary battery.