Battery Cell Injection Hole Cover for Higher Internal Pressure
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Solution Overview
Problem
Existing injection hole covers in battery cells have a low limit internal pressure resistance, leading to separation or damage as battery capacity increases, compromising the stability of the battery cell.
Innovation Solution
An injection hole cover design featuring a cover body with a convex portion and a wing portion, recessed spaces, and varying thicknesses to enhance resistance to internal pressure, preventing fracturing and improving stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a press-fit ball or flat sealing cover is used to seal the injection hole, then the injection hole can be sealed, but the limit internal pressure that the injection hole cover may withstand is low
Solution Approach 1:
The injection hole cover is divided into multiple functional parts: a cover body for sealing, a convex portion inserted into the injection hole for mechanical interlocking, and a wing portion for enhanced pressure distribution. This segmentation allows each part to perform its specific function optimally, improving both sealing reliability and internal pressure resistance simultaneously.
Solution Approach 2:
The invention transitions from a simple flat sealing cover to a three-dimensional structure with the convex portion extending into the injection hole and the wing portion extending outward. This dimensional change enables the cover to withstand higher internal pressures by distributing forces across multiple surfaces and depths, while maintaining effective sealing.
2Quantity of substance
If the battery cell size increases to increase battery capacity, then the energy storage increases, but the injection hole cover may easily be separated or damaged due to increased internal pressure
Solution Approach 1:
The convex portion is pre-formed on the injection hole cover before installation, creating a mechanical interlocking feature that proactively resists separation forces. This preliminary structural preparation ensures that when internal pressure increases due to larger battery cell size, the cover is already equipped with enhanced resistance against separation or damage.
3Ease of manufacture
If a simple flat sealing cover is used, then the manufacturing is simple, but the fracturing of the injection hole cover cannot be prevented
Solution Approach 1:
The invention modifies the geometric parameters of the sealing cover by adding the convex portion and wing portion. These parameter changes increase the structural strength and fracture resistance without significantly complicating the manufacturing process, as the features can be formed through standard molding or machining operations.
Data Source
AI summary
A battery cell includes a cell case including a case body and a cap plate, an electrode assembly, an electrode terminal, and an injection hole cover covering an injection hole formed in the cap plate. The cap plate includes a step portion recessed toward an inside of the cell case, and a recessed space formed on at least a portion of a periphery of the step portion and recessed toward an outside of the cell case, the injection hole cover includes a cover body installed on the step portion, and a convex portion extending from the cover body to be inserted into the injection hole, and the recessed space has a shape overlapping at least a portion of the cover body when the cover body is projected in a lateral direction of the cover body.