Secondary Battery Case-Vent Welding for More Internal Cell Space
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Solution Overview
Problem
Conventional secondary batteries have limited internal space for energy realization due to their structural design, which restricts their energy density and efficiency.
Innovation Solution
The design includes an open-case secondary battery with a vent and a first current collecting plate welded to both the case and the vent, optimizing the weld positions and thicknesses to maximize energy storage capacity without beaded or crimped portions, allowing for a more efficient use of space.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If conventional beading and crimping structures are used in the battery case, then structural strength and sealing are improved, but the internal space for energy storage is reduced
Solution Approach 1:
The patent removes the conventional beading and crimping structures from the battery case, extracting these elements entirely to eliminate their space-occupying effect. The case is designed with a simple cylindrical shape without protruding beaded portions or crimped sections, thereby maximizing the internal volume available for electrode assembly while maintaining structural integrity through alternative means.
Solution Approach 2:
The patent employs a thin-film case structure that replaces the bulky conventional case with beading and crimping. The case is formed with sufficient thickness to maintain strength but without additional protruding structural elements, effectively using a streamlined shell design to achieve both strength and space efficiency.
2Strength
If the case is completely closed for structural integrity, then mechanical strength is improved, but heat dissipation and safety venting are reduced
Solution Approach 1:
The patent introduces a vent as an intermediary component that mediates between the need for case integrity and the need for heat/pressure release. The vent is welded to the case at a specific position, creating a controlled opening that allows harmful factors to escape while maintaining the overall structural integrity of the case through the welded connection.
Solution Approach 2:
The vent structure enables phase transition of internal pressure and heat from a confined state to a released state. When internal pressure or temperature exceeds safe thresholds, the vent opens to allow gas or vapor to escape, transitioning the internal environment from a high-pressure/high-temperature state to a safer state, thereby preventing thermal runaway or explosion.
3Ease of manufacture
If current collecting plate is not welded to the case and vent, then assembly simplicity is improved, but electrical connection reliability and structural stability are reduced
Solution Approach 1:
The patent merges the electrical connection function and structural support function into a single integrated solution. The first current collecting plate is welded to both the case and the vent, creating a unified electrical and structural network. This welding connection simultaneously establishes reliable electrical pathways and provides mechanical stability, eliminating the need for separate connection components.
Solution Approach 2:
The first current collecting plate serves multiple functions: it collects current from the electrode assembly, provides electrical connection to the case and vent, and contributes to the structural stability of the battery. By making the current collecting plate multi-functional through welding connections, the patent reduces the number of separate components needed while enhancing overall reliability.
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 configuration maximizes the internal space for energy storage, enhancing the battery's energy density and efficiency by eliminating structural limitations that restrict energy realization.
Implementation Method 1
a first current collecting plate electrically connected to the electrode assembly, in which the first current collecting plate is welded and electrically connected to at least one of the case and the vent
Data Source
AI summary
The present invention relates to a secondary battery including: an electrode assembly; a case opened on one side and configured to accommodate the electrode assembly therein; a vent coupled to the opening of the case; and a first current collecting plate electrically connected to the electrode assembly, in which the first current collecting plate is welded and electrically connected to at least one of the case and the vent.