Cylindrical Battery Pack Partitioning to Contain Thermal Runaway
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Solution Overview
Problem
Existing battery packs face challenges in preventing thermal runaway propagation between adjacent secondary battery cells due to heat transfer and gaps that allow flame leakage, compromising safety and efficiency.
Innovation Solution
The battery pack incorporates thermal insulators between longitudinal partition plates and side surfaces of cylindrical cells, forming air layers for insulation, and uses insulating thermal resistant plates to cover side surfaces and regulate flame exhaust, along with heat absorbers to mitigate thermal runaway.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If secondary battery cells are arranged close to each other to increase capacity, then the battery pack capacity increases, but heat transfer between adjacent cells increases leading to thermal runaway propagation
Solution Approach 1:
The patent introduces thermal insulators as intermediary elements positioned between adjacent secondary battery cells. These insulators act as mediators that block heat transfer pathways while allowing the cells to remain closely arranged for high capacity. The thermal insulators are specifically placed in gap regions between cells to prevent thermal runaway propagation without sacrificing space efficiency.
Solution Approach 2:
The patent divides the battery pack into discrete segments by introducing partition structures and thermal insulators between individual cells. This segmentation creates isolated thermal zones that prevent heat propagation from one cell to another, while maintaining the overall compact arrangement. Each cell is effectively separated into its own thermal compartment.
2Object-affected harmful factors
If thermal insulators are introduced between battery cells to prevent heat transfer, then thermal insulation improves, but device complexity increases
Solution Approach 1:
The patent applies thermal insulators only in specific localized regions where heat transfer is most critical - namely in the gap regions between adjacent battery cells. Rather than insulating the entire battery pack structure, the insulators are strategically positioned only where needed to block thermal pathways, minimizing added complexity while maximizing thermal protection.
Solution Approach 2:
The patent combines multiple functions into the thermal insulator elements - they simultaneously serve as thermal barriers, structural spacers that maintain cell positioning, and flame propagation blockers. This merging of functions reduces the need for separate components, thereby limiting the increase in device complexity while achieving comprehensive thermal protection.
3Ease of manufacture
If gaps are left between partition walls and housing case for assembly, then ease of manufacture improves, but flame may leak through gaps causing thermal runaway
Solution Approach 1:
The patent introduces thermal insulators as intermediary elements that fill the gap regions between partition walls and the housing case. These insulators serve as mediators that seal the assembly gaps while maintaining the ease of assembly. The insulators are positioned to occupy the void spaces that would otherwise allow flame and heat to propagate through the partition structures.
Solution Approach 2:
The patent converts the potentially harmful effect of gap regions into a beneficial feature by filling these gaps with thermal insulator materials. The same space that would allow flame leakage is transformed into a thermal barrier zone. The assembly gaps become opportunities to add thermal protection rather than weaknesses in the design.
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
Enhances thermal insulation, reduces flame spread, and improves safety by minimizing gaps and controlling flame direction, thereby preventing unintended thermal runaway propagation.
Implementation Method 1
the thermal insulators are interposed between the longitudinal partition plate and the side surfaces of the cylindrical secondary battery cells to separate the side surfaces from the longitudinal partition plate and form an air layer in a space produced by the separation. Therefore, thermal insulation improves.
Data Source
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AI summary
A chain of thermal runaway is prevented between a plurality of secondary battery cells laterally aligned. A battery pack (100) includes: a first secondary battery cell (lA) and a second secondary battery cell (1B) each having a cylindrical shape and connected in series and/or in parallel with each other; a housing case (10) that includes an internal space for housing the first secondary battery cell (lA) and the second secondary battery cell (1B) aligned in such postures that side surfaces of the cylindrical shapes face each other; and a longitudinal partition plate (30) having a thermal insulation property, and disposed at an interface between the first secondary battery cell (lA) and the second secondary battery cell (1B) housed in the internal space of the housing case (10), at the interface the side surfaces of the cylindrical shapes of the first and second secondary battery cells (1A, 1B) facing each other, to electrically insulate the first secondary battery cell (1A) from the second secondary battery cell (1B). The longitudinal partition plate (30) constitutes a first thermal insulator (51) that projects from a side facing the side surface of the cylindrical shape of the first secondary battery cell (lA) to come into contact with the side surface of the cylindrical shape of the first secondary battery cell (lA), and constitutes a second thermal insulator (52) that projects from a side facing the side surface of the cylindrical shape of the second secondary battery cell (1B) to come into contact with the side surface of the cylindrical shape of second secondary battery cell (1B).