Battery Cell Collector Welding for Low Resistance and High-Current Fusing
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Solution Overview
Problem
Conventional battery cells face challenges in blocking high current flow while minimizing internal resistance, particularly due to the design of the collector plate and electrode tab structures.
Innovation Solution
A battery cell design featuring a collector with a support portion, tap coupling portions, and housing coupling portions, where the number of welded portions is minimized to reduce internal resistance, and a breaking portion is included to facilitate fusing under high current conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the collector plate and foil tab are welded for low resistance design, then internal resistance is reduced, but the ability to block high current flow is compromised
Solution Approach 1:
The collector is divided into multiple housing coupling portions, each with its own welded portion to the battery housing. This segmentation allows the current path to be distributed across multiple welded connections, reducing the current density at each weld while maintaining overall low resistance. The segmented structure also provides multiple potential fusing points for high current protection.
Solution Approach 2:
The battery housing serves as an intermediary component between the collector and the external environment. By welding the collector to the battery housing, the housing acts as a current sink and provides a low-resistance path for normal operation. The housing also provides mechanical support and thermal management functions.
2Reliability
If a fusing structure is designed by altering the design of the positive electrode collector plate, then high current blocking capability is improved, but internal resistance increases
Solution Approach 1:
The fusing function is extracted from the positive electrode collector plate and transferred to the housing coupling portions of the collector. This allows the collector plate itself to maintain its optimized low-resistance design for normal operation, while the housing coupling portions provide the fusing capability through their welded connections to the battery housing.
Solution Approach 2:
Instead of making the collector plate itself fusible by altering its design, the invention inverts the approach by making the housing coupling portions the fusible elements. The welded portions between the housing coupling portions and the battery housing are designed to be the weak links that fuse under high current conditions, rather than modifying the collector plate structure.
3Reliability
If multiple welded portions are provided between housing coupling portions and battery housing, then electrical coupling is improved, but device complexity increases
Solution Approach 1:
The battery housing serves multiple functions: it provides mechanical containment for the electrode assembly, acts as a thermal management interface, serves as an electrical connection point through welded portions, and provides structural support. By making the housing multi-functional, the number of separate components is reduced, and the welded portions serve both electrical and mechanical purposes.
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
The design effectively blocks high current flow while minimizing internal resistance and enhances fusing capabilities during high current conditions, improving safety and performance.
Implementation Method 1
a housing coupling portion extending from the support portion to be electrically coupled to the inner surface of the battery housing and including at least one welded portion welded to the inner surface of the between housing
Implementation Method 2
a breaking portion configured to have lower strength than the surrounding area may be provided at the boundary between the support portion and the housing coupling portion
Data Source
AI summary
A battery cell may include an electrode assembly in which a first electrode and a second electrode are wound around a winding axis while a separator is interposed therebetween, the first electrode including a first non-coated portion that is not coated with an active material layer, a battery housing accommodating the electrode assembly therein, a collector including a support portion disposed on an upper portion of the electrode assembly, a tap coupling portion, a housing coupling portion including at least one welded portion welded to the inner surface of the between housing, and a housing cover configured to cover the opening, wherein the number of welded portions may be smaller than or equal to the number of tap coupling portions, or wherein a breaking portion configured to have lower strength than the surrounding area may be provided at the boundary between the support portion and the housing coupling portion.