Battery Module Venting Structure for Spark Containment
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Solution Overview
Problem
Battery modules in energy storage systems and electric vehicles face challenges in rapidly discharging venting gas and preventing high-temperature sparks from leaking, which can lead to fires and explosions, especially when internal structures are damaged by sparks and high-temperature gases.
Innovation Solution
A battery module design featuring a cell stack with vertically stacked cells, a module housing with bent side plates to redirect sparks, a bus bar frame assembly, and a fire-proof mica sheet between the bus bar frame and cell stack, which includes slits and protrusions for secure attachment, allowing rapid venting of gases while preventing external oxygen ingress and spark ejection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stress or pressure
If venting gas is rapidly discharged to the outside of the battery module, then internal pressure of the battery module is prevented from increasing, but high-temperature sparks containing electrode active material and aluminum particles are ejected along with the venting gas causing fire
Solution Approach 1:
A fireproof sheet is introduced as an intermediary component between the battery cells and the external environment. This sheet allows venting gas to pass through while blocking high-temperature sparks, thus mediating between the need for pressure relief and the need to prevent fire hazards from spark ejection
Solution Approach 2:
The fireproof sheet creates a protective barrier that effectively introduces an inert environment between the sparks and external oxygen, preventing the combustion reaction that would otherwise occur when sparks contact oxygen in the air
2Reliability
If a bus bar frame structure is used to prevent short circuit between lithium secondary batteries, then electrical safety is improved, but the structure is damaged by continuous contact with spark and high-temperature gas causing oxygen ingress and fire spread
Solution Approach 1:
The fireproof sheet serves as a sacrificial protective component that can be damaged or consumed during thermal events, protecting the more critical and expensive bus bar frame structure from damage. The sheet acts as a disposable barrier that absorbs the impact of sparks and high-temperature gases
Solution Approach 2:
The fireproof sheet is positioned in advance to cushion and absorb the impact of sparks and high-temperature gases before they can reach and damage the bus bar frame structure, preventing structural integrity loss
3Quantity of substance
If the number of lithium secondary batteries in a battery module is increased to satisfy output power characteristics, then capacity and power output are improved, but damage increases when fire or explosion occurs
Solution Approach 1:
The battery module is segmented into multiple compartments by fireproof sheets and housing structures, creating physical barriers that can contain thermal events to specific sections. This segmentation prevents fire or explosion from spreading throughout the entire module, thus reducing overall damage even when the number of cells is increased
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
Effectively prevents high-temperature sparks from leaking outside and minimizes the risk of fire spread by rapidly discharging venting gases and preventing external oxygen introduction, even when internal structures are damaged, thereby enhancing safety and preventing short circuits between adjacent lithium secondary batteries.
Implementation Method 1
a fire-proof sheet located between the bus bar frame assembly and the cell stack... effectively preventing a high-temperature spark containing electrode active material and aluminum particles from leaking to the outside
Implementation Method 2
a pair of side plates covering both side portions of the cell stack and each including a spark direction changing portion formed by bending an end portion of the side plate in a longitudinal direction of the side plate toward the cell stack
Implementation Method 3
When a temperature of a lithium secondary battery abnormally rises and internal gas is generated, and thus internal pressure of the lithium secondary battery increases to a certain level or higher, venting of the lithium secondary battery occurs, and thus, high-temperature gas is ejected to the outside
Data Source
AI summary
A battery module ac includes a cell stack in which a plurality of battery cells are vertically stacked; a module housing including a base plate supporting the cell stack, and a pair of side plates covering both side portions of the cell stack and each including a spark direction changing portion formed by bending an end portion of the side plate in a longitudinal direction of the side plate toward the cell stack; and a bus bar frame assembly covering an opening portion formed on a side of the module housing in a longitudinal direction of the module housing, the bus bar frame assembly including a bus bar frame coupled to a side of the cells tack in a longitudinal direction of the cell stack and a bus bar located on the bus bar frame and coupled to an electrode lead of the battery cell.