Bus Bar Holder Vent Structure for Fast Battery Cell Gas Discharge
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Solution Overview
Problem
Existing battery modules face challenges in quickly discharging vent gas due to small vent holes in the bus bar holder, which can lead to heat propagation and thermal runaway, especially with increasing cell capacity.
Innovation Solution
The bus bar holder in the battery module features a module vent with bending and rupture guide grooves that expand under high pressure to match the size of the cell vent, facilitating rapid gas discharge and preventing heat propagation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the vent hole size in the bus bar holder is increased to match the cell vent size, then vent gas discharge speed is improved, but component mounting space is reduced
Solution Approach 1:
The bus bar holder incorporates bending guide grooves that enable the holder to dynamically deform under pressure. During normal operation, the vent hole remains small to preserve mounting space. When thermal runaway occurs and pressure increases, the bending guide grooves allow the bus bar holder to expand and widen the vent hole, increasing discharge speed while maintaining component mounting space during normal operation.
Solution Approach 2:
The invention changes the physical state and dimensions of the vent hole based on operating conditions. The vent hole transitions from a small size during normal operation to a large size during thermal runaway events. This parameter change is achieved through the bending guide grooves that enable pressure-induced expansion, allowing the system to optimize both mounting space and gas discharge speed at different operational stages.
2Area of stationary object
If the vent hole size is kept small to maintain component mounting space, then component mounting is facilitated, but vent gas discharge speed is reduced
Solution Approach 1:
The bus bar holder is designed with bending guide grooves that enable it to transition from a rigid small-vent-hole structure during normal operation to an expanded large-vent-hole structure during thermal runaway. This dynamic transformation allows the system to maintain component mounting space under normal conditions while achieving high-speed gas discharge when needed.
Solution Approach 2:
The bending guide grooves are pre-formed in the bus bar holder during manufacturing, preparing the structure for future pressure-induced expansion. This preliminary action ensures that when thermal runaway occurs, the bus bar holder can rapidly expand to increase vent hole size without requiring complex real-time control mechanisms.
3Quantity of substance
If a larger cell vent is used to increase energy capacity, then energy capacity is improved, but heat propagation risk increases due to insufficient venting
Solution Approach 1:
The bus bar holder acts as an intermediary structure between the cell vent and the external environment. The bending guide grooves in the bus bar holder enable it to expand and create a larger vent opening that matches the cell vent size during thermal runaway, facilitating rapid gas discharge and preventing heat propagation to adjacent cells while allowing larger cell vents for increased energy capacity.
Solution Approach 2:
The invention converts the harmful high-pressure gas generated during thermal runaway into a beneficial force that expands the bus bar holder and opens the vent hole. The pressure that would otherwise cause heat propagation is instead utilized to automatically enlarge the vent opening, accelerating gas discharge and protecting adjacent cells from thermal runaway.
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 solution ensures quick venting of gas, maintaining component mounting space and preventing thermal runaway, thus enhancing safety and performance.
Implementation Method 1
when an event occurs in a cell, the size of the vent hole increases to be the same or similar level as the size of a cell vent because some regions of the vent hole are removed due to the high temperature and pressure of vent gas and the remaining regions are widened in the direction of gas discharge due to high pressure during gas discharge
Implementation Method 2
the size of the vent hole increases to be the same or similar level as the size of a cell vent because some regions of the vent hole are removed due to the high temperature and pressure of vent gas and the remaining regions are widened in the direction of gas discharge due to high pressure during gas discharge
Data Source
Figure 1A~1B
Figure 1C~1D
Figure 1E
AI summary
A battery module includes: a battery cell having a cell vent; and a bus bar holder on the battery cell and having a module vent. The module vent has a flat first surface, a flat second surface opposite to the first surface and facing the battery cell, a vent hole extending between the first and second surfaces and facing the cell vent, and a plurality of bending guide grooves in a partial region of the first surface spaced apart from the vent hole.