Wound Secondary Battery Current Collector Insulation at the Winding Center
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Solution Overview
Problem
Lithium secondary batteries are prone to structural collapse, oxidation, and potential explosion due to excessive reactions between the positive electrode active material and electrolyte, especially from overcharging, which can lead to deformation and safety hazards.
Innovation Solution
The design incorporates a secondary battery structure with a first and second electrode plate, a separator, and current collecting plates, where the second current collecting plate's end part is coupled with an insulation member, and a center pin protrudes from the lower current collecting plate, stabilizing the assembly and preventing electrical shorts through insulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the second current collecting plate is extended to penetrate the winding center for better electrical connection, then electrical conductivity is improved, but the risk of electrical short between current collecting plates increases
Solution Approach 1:
An insulation member is introduced as an intermediary component between the first and second current collecting plates. This insulation member is positioned at the winding center and pressed by the end part of the second current collecting plate, providing electrical isolation while allowing the second current collecting plate to maintain its extended configuration for reliable electrical connection.
2Reliability
If the end part of the second current collecting plate is extended farther to improve current collection, then electrical performance is improved, but structural stability and risk of deformation increase
Solution Approach 1:
The insulation member is positioned in advance at the winding center to prevent potential deformation and structural instability. By pressing the insulation member with the end part of the second current collecting plate during assembly, the structure is pre-stabilized before any operational stresses occur, counteracting potential deformation forces.
Solution Approach 2:
The insulation member acts as a mediator that allows the end part of the second current collecting plate to extend farther for improved current collection while preventing direct contact and potential structural interference with the first current collecting plate, thereby maintaining structural stability.
3Reliability
If insulation measures are added to prevent electrical shorts, then safety is improved, but device complexity increases
Solution Approach 1:
The insulation member serves multiple functions simultaneously: it provides electrical insulation between current collecting plates, acts as a structural support element at the winding center, and facilitates the coupling of the second current collecting plate. This multi-functionality improves safety while minimizing the increase in device complexity.
Solution Approach 2:
The insulation function is merged with the structural support function in a single component. Rather than adding separate insulation elements and support structures, the insulation member combines both roles, improving safety without proportionally increasing device complexity.
Data Source
AI summary
A secondary battery comprises: an electrode assembly in which a first electrode plate having a first non-coated part protruding in a first direction, a second electrode plate having a second non-coated part protruding in a second direction opposite to the first direction, and a separator between the first electrode plate and the second electrode plate, are wound; a first current collecting plate electrically coupled to the first non-coated part; a second current collecting plate electrically coupled to the second non-coated part, and having an end part protruding beyond the first current collecting plate by penetrating the winding center of the electrode assembly; and an insulation member between the end part of the second current collecting plate and the first current collecting plate, wherein the end part of the second current collecting plate is coupled with the insulation member.