Pouch Battery Cell Sealing Structure Without Shark-Fin Protrusions
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Solution Overview
Problem
Pouch-type secondary battery modules or packs have lower volume density and cooling efficiency due to protruding portions, such as 'shark-fins' or 'bat ears', which are non-sealing surfaces at the ends of three-side sealing pouch-type batteries.
Innovation Solution
A rechargeable-battery cell design featuring a sealing member with the same or smaller thickness than the electrode assembly, eliminating protruding portions by ensuring the sealing member has a uniform or varying thickness, with a hexahedral shape and venting holes, to prevent external leakage and electrical interference, and is disposed at both ends of the electrode assembly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a three-side sealing pouch-type secondary battery is used, then the battery structure is simpler and easier to manufacture, but protruding portions (shark-fins or bat ears) are formed which reduce volume density and cooling efficiency
Solution Approach 1:
The patent changes the thickness parameter of the sealing member to be equal to or less than the thickness of the electrode assembly. This parameter adjustment eliminates the formation of protruding portions while maintaining the three-side sealing structure, thereby improving volume density without significantly increasing manufacturing complexity
Solution Approach 2:
The patent applies excessive action by making the sealing member thickness equal to or less than the electrode assembly thickness, which is more restrictive than traditionally required. This ensures complete elimination of protruding portions and achieves optimal volume density and cooling efficiency
2Ease of manufacture
If a three-side sealing pouch-type secondary battery is used, then the battery structure is simpler and easier to manufacture, but protruding portions (shark-fins or bat ears) are formed which reduce cooling efficiency
Solution Approach 1:
The patent changes the thickness parameter of the sealing member to be equal to or less than the thickness of the electrode assembly. This parameter adjustment eliminates the formation of protruding portions that interfere with cooling, thereby improving cooling efficiency while maintaining manufacturing simplicity
Solution Approach 2:
The patent applies excessive action by making the sealing member thickness equal to or less than the electrode assembly thickness, ensuring complete elimination of protruding portions that would otherwise hinder cooling efficiency
3Reliability
If the sealing member has greater thickness than the electrode assembly, then sealing performance is improved, but protruding portions are formed which reduce volume density
Solution Approach 1:
The patent inverts the traditional parameter relationship by making the sealing member thickness equal to or less than the electrode assembly thickness. This counterintuitive parameter change eliminates protruding portions and improves volume density while maintaining adequate sealing performance through proper material selection and sealing design
Solution Approach 2:
The patent applies inversion by reversing the conventional approach where the sealing member is typically thicker than the electrode assembly. By making the sealing member equal to or thinner, the patent eliminates protruding portions and achieves better volume density and cooling efficiency
Data Source
AI summary
A rechargeable-battery cell includes: an electrode assembly including a first electrode plate, a separator, and a second electrode plate; an electrode lead portion connected to a first or second uncoated electrode portion extending from the first or second electrode plate of the electrode assembly; a sealing member through which the electrode lead portion passes; and an exterior material from which portions of the sealing member and the electrode lead portion are externally exposed and in which the electrode structure is disposed, wherein the sealing member has the same thickness as or a thickness smaller than that of the electrode assembly.