Hybrid Battery Cell Housing for Thermal Fault Ejection
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Solution Overview
Problem
Electrical storage cells can experience high-energy releases due to faults, leading to overheating and uncertain damaging consequences, which existing technologies fail to adequately address.
Innovation Solution
A battery cell design featuring a hybrid cell housing with a plastic inner subhousing and a thermally conductive metal outer subhousing, equipped with a protection apparatus that allows the cell core to be ejected from the outer subhousing in the event of a thermal fault, utilizing gas pressure or a miniature airbag to facilitate ejection and maintain system functionality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If a traditional single-material cell housing is used, then manufacturing is simpler, but weight reduction and thermal management are insufficient
Solution Approach 1:
The cell housing is divided into two distinct subhousings: an inner subhousing made from electrically insulating material (such as plastic) and an outer subhousing made from electrically conductive and thermally conductive material. This segmentation allows each subhousing to perform its specific function optimally while reducing overall weight compared to a single-material construction.
Solution Approach 2:
The hybrid cell housing combines two different materials with complementary properties: electrically insulating material for the inner subhousing and electrically conductive/thermally conductive material for the outer subhousing. This composite structure achieves both weight reduction and improved thermal management without requiring a completely complex design.
2Reliability
If no protection apparatus is provided, then device complexity is lower, but safety in case of thermal fault is insufficient
Solution Approach 1:
The protection apparatus is pre-configured within the cell housing before any fault occurs. The ejection mechanism, gas-tight cavity, and seal are all prepared in advance, so that in the event of a thermal fault, the cell core can be rapidly ejected without requiring complex real-time decision systems or additional activation components.
Solution Approach 2:
The protection apparatus converts the harmful effect of thermal expansion and gas pressure buildup during a fault into a beneficial ejection force. The gas-tight cavity captures the expanding gas and uses its pressure to automatically eject the cell core from the housing, transforming a potentially damaging phenomenon into a safety mechanism.
3Temperature
If the cell housing is made entirely from thermally conductive metal, then thermal management is improved, but weight increases and electrical insulation is lost
Solution Approach 1:
The housing is segmented into inner and outer subhousings with different material properties. The inner subhousing uses electrically insulating material to maintain electrical isolation, while the outer subhousing uses thermally conductive material for heat dissipation. This segmentation allows thermal management without requiring the entire housing to be made of heavy metal.
Solution Approach 2:
Different regions of the housing have different material qualities tailored to their specific functions. The inner subhousing prioritizes electrical insulation where it contacts the cell core, while the outer subhousing prioritizes thermal conduction for heat management. This local differentiation optimizes performance while minimizing weight.
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 reduces weight, stabilizes against mechanical forces, and prevents greater damage by enabling controlled ejection of the faulty cell, maintaining system functionality and safety, especially in autonomous driving scenarios.
Implementation Method 1
a gas-tight cavity is created in which, by introducing gas (for example, in the case of an event which causes the inner subhousing to burst with the escape of gas, or in the case of additional use of a 'miniature airbag' which is defined more precisely below), pressure can be built up in a targeted fashion and used to eject the inner subhousing in the ejection direction
Implementation Method 2
an outer subhousing in the form of a cell holder made from electrically conductive and thermally conductive material
Data Source
AI summary
A battery cell for an electrical energy storage device for installation in an electrified motor vehicle having a large number of battery cells. The battery cell includes a cell core and a hybrid cell housing. The hybrid cell housing includes an inner housing element with an outer housing element, and a protection apparatus, by way of which the cell core together with the inner housing element can be ejected from the outer housing element in the event of a (preferably thermal) fault. The outer housing element may include a gas-tight closure in the direction opposite to the ejection direction, the gas-tight closure creating a gas-tight cavity in which, for example in the case of an event that leads to the inner housing element bursting, pressure is deliberately created by gas and used to eject the inner housing element in the ejection direction.