Narrow Metal Layer Pouch Case Prevents Battery Short Circuits
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Solution Overview
Problem
The existing pouch cases for secondary batteries often result in short circuits during manufacturing due to exposed metal layers contacting the outer casing, increasing material costs and reducing productivity with the need for separate insulation treatments.
Innovation Solution
A pouch case design where the metal layer is formed narrower than other layers, interposed between internal and external insulating layers, and not exposed to the outer surface, eliminating the need for a separate insulation treatment process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the metal layer width is the same as other layers in the pouch case, then the pouch case structure is simple and easy to manufacture, but the metal layer is exposed to the outer surface causing short circuits and requiring separate insulation treatment
Solution Approach 1:
The metal layer is designed with a narrower width than the insulating layers, creating a local dimensional difference. This local quality change ensures the metal layer is not exposed at the outer surface of the pouch case, preventing short circuits without requiring additional insulation treatments. The different width specification is applied locally to the metal layer while maintaining the overall multi-layer structure.
2Reliability
If a separate insulation treatment process is added to prevent short circuits, then reliability is improved, but manufacturing complexity and time increase
Solution Approach 1:
The pouch case structure is designed in advance with the metal layer width intentionally made narrower than the insulating layers. This preliminary design action prevents metal layer exposure before the battery assembly process begins, eliminating the need for subsequent insulation treatment steps. The prevention is built into the structure itself rather than added as a separate process.
Solution Approach 2:
The separate insulation treatment process is extracted and eliminated from the manufacturing workflow. By designing the pouch case with the metal layer narrower than insulating layers, the function of preventing short circuits is achieved through the structure itself, making additional insulation treatments redundant and removable from the process.
3Reliability
If the metal layer width is reduced to prevent exposure, then short circuit risk is eliminated, but the amount of metal material used decreases
Solution Approach 1:
The metal layer width is reduced only at the edges where exposure would occur, while maintaining sufficient width in the central functional areas. This local quality adjustment prevents short circuits at the outer surface while preserving adequate metal material for the battery's electrical functions. The width reduction is applied selectively rather than uniformly across the entire metal layer.
Data Source
AI summary
A pouch case for a secondary battery in which the width of a metal layer in a plurality of layers to constitute the pouch case is formed narrower than those of other layers so that the metal layer is not exposed to an outer surface of the pouch case. A secondary battery includes an electrode assembly provided with one or more electrode tabs. A pouch case has the electrode assembly accommodated therein, and is formed of a plurality of layers. In the secondary battery, any one of the plurality of layers to constitute the pouch case is formed as a metal layer of which width is narrower than those of the other layers.