Multi-Layer Battery Insulation for Thermal Runaway Delay
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Solution Overview
Problem
Existing heat insulation solutions for batteries, such as lithium-ion batteries in electric vehicles, are inadequate in providing efficient, robust, and flexible thermal insulation, often leading to premature failure and increased risk of explosion due to brittleness and mechanical stress during uncontrolled heat events.
Innovation Solution
A multi-layer heat insulation element comprising a fibre layer of long fibres (over 30 mm) with high mechanical resistance, a compressible and flexible cover layer, and a heat-resistant interlayer, which absorbs pressure and reduces thermal energy transfer, while being lightweight and easy to integrate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If existing heat insulation solutions are used for batteries, then thermal insulation is provided, but the insulation fails prematurely and increases explosion risk due to brittleness and mechanical stress
Solution Approach 1:
The patent applies composite materials by combining a fibre layer (made of inorganic fibres such as glass fibres or silicate fibres) with a binder layer containing a thermally active material. This composite structure provides both thermal insulation functionality and mechanical strength, resolving the contradiction between heat insulation effectiveness and mechanical resistance. The fibre network provides structural integrity while the thermally active material provides heat absorption capacity.
Solution Approach 2:
The patent changes the physical parameters of the insulation material by using fibres with specific length (at least 3 mm, preferably at least 5 mm) and diameter (at least 4 μm), and by controlling the binder layer thickness (between 0.1 mm and 5 mm). These parameter optimizations ensure the material maintains mechanical strength under thermal stress while providing effective thermal insulation.
2Temperature
If thermally active material is used in battery housing, then heat transformation occurs above certain temperature, but mechanical stress and destruction of battery cells cannot be effectively contained
Solution Approach 1:
The patent segments the thermal management function by placing the thermally active material specifically in the binder layer between battery cells, rather than in the entire battery housing. This localized segmentation allows heat transformation to occur at the critical interface between cells while the outer fibre layer maintains mechanical strength and contains stress.
Solution Approach 2:
The patent implements beforehand cushioning by pre-positioning the thermally active material in the binder layer to absorb thermal energy before it can cause mechanical stress or destruction of battery cells. The fibre layer also provides pre-established mechanical cushioning against thermal expansion forces.
3Reliability
If protective material is arranged between battery cells, then thermal insulation is provided, but the material may burst and lose insulation function prematurely
Solution Approach 1:
The composite structure of fibre layer plus binder layer creates a material that is more resistant to bursting than either component alone. The fibre network provides tensile strength while the binder layer provides flexibility and heat absorption, together preventing premature failure and reducing explosion risk.
Solution Approach 2:
The patent optimizes material parameters including fibre length (at least 3 mm), fibre diameter (at least 4 μm), and binder layer thickness (0.1-5 mm) to ensure the protective material can withstand thermal runaway conditions without bursting, thereby maintaining insulation function and reducing harmful effects.
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 and contains heat transfer, reducing the risk of battery explosion and providing sufficient time for rescue measures by maintaining temperature below critical levels, while also offering mechanical protection and efficient thermal insulation.
Implementation Method 1
The heat insulation element has a layered structure with an intermediate ply arranged between two cover layers. The intermediate ply has at least one fibre layer which comprises long fibres of more than 30 mm in length and/or a needled or bonded nonwoven.
Implementation Method 2
The battery housing contains a thermally active material, for example aluminium silicate or gibbsite, which transforms above a certain temperature, whereby further supplied thermal energy is consumed for the progressive transformation and thus a rise in temperature is at least slowed down.
Implementation Method 3
Above a predetermined temperature, the protective material expands and the battery cells insulated from one another are pushed away from one another by the increase in volume of the protective material which expands under the effect of temperature.
Data Source
AI summary
A multi-layer heat insulation element for thermal insulation of a battery is proposed, with a first cover layer, with a second cover layer and with a compressible and/or pliable intermediate ply arranged between the cover layers, which has at least one heat-resistant fibre layer, wherein the fibre layer is formed from a needled nonwoven and/or wherein the cover layers are flexurally weak and the heat insulation element as a whole is compressible and flexibly pliable.