Battery Module Layout With Low-Resistance Cells for Thermal Propagation Delay
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Solution Overview
Problem
Existing battery modules face challenges in delaying thermal propagation between cells when an abnormality occurs, particularly in large-capacity modules used in vehicles, due to high resistance and potential overheating.
Innovation Solution
Incorporating a battery cell with lower resistance into the stack, connected in series with higher resistance cells, and using a temperature sensor to rapidly switch the lower resistance cell to parallel connection upon detection of abnormality, thereby facilitating faster discharge and reducing thermal propagation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a large number of battery cells are connected in series or parallel to form a battery cell stack to improve capacity and output, then the capacity and output of the battery module are improved, but when thermal runaway occurs in some battery cells, thermal propagation between battery cells occurs more rapidly
Solution Approach 1:
The battery module is segmented into two distinct groups: first battery cells with normal resistance and second battery cells with low resistance. This segmentation allows the low-resistance cells to serve a protective function by rapidly discharging and cooling during thermal events, while the normal cells maintain standard capacity and output functions.
Solution Approach 2:
The second battery cells with low resistance act as intermediary elements between the first battery cells. When thermal runaway occurs in a first battery cell, the low-resistance cell rapidly discharges to cool the affected area, serving as a thermal buffer that prevents thermal propagation to adjacent cells.
2Device complexity
If battery cells with normal resistance are used throughout the stack, then the structure is simple and uniform, but the ability to delay thermal propagation when abnormality occurs is insufficient
Solution Approach 1:
Instead of uniform battery cells throughout the stack, the invention applies local quality by placing second battery cells with low resistance at specific positions within the battery cell stack. These localized low-resistance cells provide enhanced thermal protection at critical locations without requiring all cells to have modified properties.
Solution Approach 2:
The invention changes the resistance parameter of specific battery cells to create a functional differentiation. Second battery cells have lower resistance than first battery cells, and this parameter change enables them to discharge more rapidly during thermal events, providing active thermal management capability.
3Reliability
If a battery cell with lower resistance is inserted into the battery cell stack, then the ability to delay thermal propagation is improved, but the device complexity increases due to mixed cell types
Solution Approach 1:
The battery module is segmented into two distinct groups: first battery cells with normal resistance and second battery cells with low resistance. This segmentation allows the low-resistance cells to serve a protective function by rapidly discharging and cooling during thermal events, while the normal cells maintain standard capacity and output functions.
Solution Approach 2:
The second battery cells with low resistance serve multiple functions: they contribute to the overall capacity and output of the battery module like normal cells, but additionally provide thermal protection by rapidly discharging during thermal runaway events. This multi-functionality justifies the increased device complexity.
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 effectively delays thermal propagation by rapidly discharging the lower resistance cell, utilizing its energy to operate a cooling system and reducing heat generation, enhancing safety and efficiency in battery modules and packs.
Implementation Method 1
when an abnormality is detected in some of the battery cells included in the battery module, a battery cell having a relatively low resistance is discharged at a faster speed to delay thermal propagation between battery cells
Data Source
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AI summary
A battery module according to one embodiment of the present disclosure comprises a battery cell stack including a plurality of first battery cells with at least one second battery cell being inserted between the plurality of first battery cells; a module frame that houses the battery cell stack; and a temperature sensor that is located inside the module frame, and detects whether the plurality of first battery cells and the at least one second battery cell are abnormal or not, wherein the second battery cell has a resistance smaller than that of the first battery cell.