Battery Module Case Welding for Airtight Thermal Runaway Containment
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Solution Overview
Problem
Conventional battery modules have inadequate airtightness, leading to the indiscriminate discharge of gas or flame during ignition, which facilitates rapid fire spread to surrounding modules.
Innovation Solution
A battery module design featuring a module case with a case body and top plate that are welded together without gaps, using a clad metal structure with dissimilar metals for enhanced heat resistance and airtightness, and incorporating assembly guide protrusions and holes for precise alignment and welding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a groove structure with sealing material is used to join the U frame and top plate, then assembly ease is improved, but airtightness deteriorates because the sealing material melts and disappears at high temperature
Solution Approach 1:
The patent replaces the mechanical sealing system (groove + sealing material) with a welding system that creates a metallurgical bond between the U frame and top plate. This substitution eliminates the reliance on heat-resistant sealing materials while maintaining assembly feasibility through standardized welding procedures.
Solution Approach 2:
The patent employs a composite structure consisting of the U frame, top plate, and welding bead line forming an integrated joint. The welding bead line acts as a composite material that combines the structural integrity of metal-to-metal bonding with the sealing function, creating a unified assembly that resists high-temperature degradation.
2Weight of moving object
If aluminum-based metal is used for the module housing, then weight is reduced, but heat resistance deteriorates due to thermal deformation at certain temperatures
Solution Approach 1:
The patent changes the material parameter of the module housing from pure aluminum-based metal to a composite structure including steel components. This parameter change increases heat resistance while managing weight through the optimized combination of lightweight aluminum and high-temperature-resistant steel in critical areas.
Solution Approach 2:
The patent creates a composite housing structure that combines aluminum-based materials for weight reduction with steel components for heat resistance. The welding bead line joining these dissimilar metals forms a composite joint that leverages the advantages of both materials while mitigating their individual limitations.
3Ease of manufacture
If the module housing is made of a single metal, then manufacturing simplicity is improved, but airtightness deteriorates due to thermal deformation during ignition
Solution Approach 1:
The patent transitions from a single-metal construction to a composite structure involving multiple metals (aluminum-based and steel) joined by welding. This composite approach maintains manufacturing simplicity through standardized welding processes while dramatically improving airtightness under thermal stress by combining materials with complementary properties.
4Ease of manufacture
If plastic injection molding is used for front and rear covers, then manufacturing cost is reduced, but airtightness deteriorates due to difficulty in welding assembly
Solution Approach 1:
The patent changes the material parameter of the front and rear covers from plastic to metal (aluminum-based). This parameter change enables welding-based assembly that ensures airtightness while maintaining manufacturing efficiency through standardized metal forming and welding processes.
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
The design ensures airtightness is maintained during ignition, preventing the discharge of gas or flame, and provides improved heat resistance and mechanical rigidity compared to prior art.
Implementation Method 1
the entire outer circumference of the portion where the open end of the case body and the edge of the top plate are in contact with each other is welded without a gap
Implementation Method 2
a module case composed of a case body having an inner space for accommodating the battery cell and an open end on the upper side; and a top plate that covers the upper side of the case body and is coupled to the upper portion of the case body, wherein the open end of the case body has an assembly guide protrusion protruding upward from the surface thereof
Data Source
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AI summary
A battery module according to the present disclosure includes at least one battery cell; and a module case composed of a case body having an inner space for accommodating the battery cell and an open end on the upper side; and a top plate that covers the upper side of the open case body and is coupled to the upper portion of the case body, wherein the open end of the case body has an assembly guide protrusion protruding upward from the surface thereof, and the top plate has an assembly guide hole that is press-fitted with the assembly guide protrusion at an edge thereof, and the entire outer circumference of the portion where the open end of the case body and the edge of the top plate are in contact with each other is welded.