Battery Enclosure Protrusions for Pressure-Resistant Weld Seals
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Solution Overview
Problem
Conventional battery enclosures face structural integrity issues due to expansion and pressure increases, leading to seam failure and loss of hermeticity, which can result in reduced energy density and increased footprint, as they struggle to accommodate the strain caused by internal gas formation and cell swelling.
Innovation Solution
The introduction of protrusions at specific locations on the exterior of the battery enclosure provides structural reinforcement, minimizing the impact on the overall footprint while enhancing the battery's ability to withstand internal pressure, using a rigid housing with a conductive lid welded to the flange, and a recessed weld seam to distribute strain effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the battery enclosure uses a conventional rigid housing without protrusions, then the manufacturing process is simpler, but the structural integrity deteriorates under internal pressure causing seam failure and loss of hermeticity
Solution Approach 1:
The patent applies local quality by adding protrusions only at specific predetermined strain locations on the enclosure, rather than uniformly thickening the entire structure. These localized protrusions provide targeted structural reinforcement where internal pressure causes maximum stress, while maintaining simplicity in other areas. The protrusions are positioned based on finite element analysis to coincide with areas of highest strain, creating non-uniform thickness distribution that optimizes strength where needed.
Solution Approach 2:
The enclosure is segmented into regions of different thickness by adding discrete protrusions at specific locations. This segmentation allows the structure to have varying mechanical properties in different areas - thicker at strain locations for strength, and thinner elsewhere to minimize overall footprint and material usage. The enclosure body and lid are also segmented with corresponding protrusions that work together to distribute stress.
2Strength
If the battery enclosure is designed with larger dimensions to accommodate swelling, then the structural integrity is maintained, but the footprint increases which reduces energy density
Solution Approach 1:
Instead of uniformly increasing the enclosure size to accommodate swelling, the patent uses local quality by adding protrusions only at specific strain locations. This creates localized thickness variations that provide structural reinforcement where needed without increasing the overall footprint. The enclosure maintains its compact dimensions while having enhanced strength at critical areas through the protrusion geometry.
Solution Approach 2:
The patent addresses the footprint issue by transitioning from a two-dimensional uniform thickness approach to a three-dimensional variable thickness approach. Protrusions add depth in specific dimensions at strategic locations, creating a non-uniform thickness profile that provides structural reinforcement without increasing the planar footprint. This dimensional change allows the enclosure to maintain compact dimensions while having enhanced volume at critical stress points.
3Reliability
If the weld seam is positioned closer to the exterior edge of the lid, then the sealing effectiveness is improved, but the strain concentration increases at the weld location under internal pressure
Solution Approach 1:
The patent applies local quality by adding protrusions that create localized thickness variations near the weld seam areas. These protrusions modify the stress distribution locally, reducing strain concentration at the weld while maintaining the weld's proximity to the exterior edge for effective sealing. The variable thickness profile created by protrusions provides structural support exactly where the weld seam is located, allowing the seam to be positioned optimally for hermeticity without suffering from excessive strain.
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 design improves structural integrity and maintains energy density by reducing seal rupturing and increasing the operational pressure range without significantly increasing the battery's size, thus addressing the limitations of conventional technologies.
Implementation Method 1
The lid may be welded to the rigid housing along the flange of the rigid housing, and a weld seam may extend about the enclosure.
Data Source
AI summary
Batteries according to embodiments of the present technology may include an electrode stack including a separator positioned between an anode and a cathode. The batteries may include an electrolyte. The batteries may include an enclosure extending about the electrode stack and containing the electrolyte. The enclosure may include a rigid housing defining a volume in which the electrode stack and the electrolyte are contained. The rigid housing may define a flange extending about the rigid housing. The enclosure may include a lid extending across the rigid housing. The lid may be characterized by a length and a width, and the lid may define a protrusion extending beyond the length or width on a side of the lid at a location corresponding to a predetermined strain location.