Thermally Conductive Interface Material for EV Battery Packs
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Solution Overview
Problem
Current thermally conductive interface devices for electric vehicle battery packs are unable to meet the requirements of being cost-effective, lightweight, low specific gravity, low hardness, high compression set resistance, flame retardant, high thermal conductivity, and high electrical insulation simultaneously.
Innovation Solution
A thermally conductive interface device is designed using a composition of at least one silicone base, one or more inorganic fillers such as alumina and boron nitride, and at least one silicone oil, with optional additives like a peroxide cross-linking agent and flame retardant, to achieve the desired properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If thermally conductive fillers are loaded to increase thermal conductivity, then thermal conductivity is improved, but specific gravity increases and compression set resistance decreases
Solution Approach 1:
The patent uses a composite material system combining silicone base polymer with thermally conductive fillers (alumina, boron nitride, zinc oxide) and silicone oil. This composite approach allows achieving high thermal conductivity (0.3-5.0 W/m·K) while maintaining low specific gravity (1.8-2.5 g/cm³) by optimizing the filler loading ratio and selecting lightweight filler materials with appropriate density.
2Temperature
If thermally conductive fillers are loaded to increase thermal conductivity, then thermal conductivity is improved, but compression set resistance decreases
Solution Approach 1:
The patent optimizes the filler loading ratio and particle size distribution parameters to maintain compression set resistance above 50% after 24 hours at 70°C. By controlling filler content and using a combination of different filler types with varying hardness and thermal conductivity, the material achieves balanced performance with compression set resistance >50% and thermal conductivity 0.3-5.0 W/m·K.
Solution Approach 2:
The composite formulation combines multiple filler types (alumina, boron nitride, zinc oxide) with silicone base polymer and silicone oil to create a synergistic effect. This composite structure maintains compression set resistance by distributing stress across different filler particles with varying mechanical properties while achieving desired thermal conductivity.
3Temperature
If conventional materials are used to achieve high thermal conductivity, then thermal conductivity is improved, but electrical insulation decreases
Solution Approach 1:
The patent achieves the dual requirement of thermal conductivity (0.3-5.0 W/m·K) and electrical insulation (dielectric strength >5 kV/mm) by optimizing the filler type selection and loading ratio. Using inorganic fillers like alumina and boron nitride with appropriate surface treatments, the material conducts heat effectively while maintaining electrical insulation properties through the silicone polymer matrix and controlled filler distribution.
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 device achieves improved thermal conductivity, dielectric strength, and compression set resistance while minimizing complexity, weight, and cost, making it suitable for efficient heat management in electric vehicle battery packs.
Implementation Method 1
a thermally conductive interface device... one or more inorganic fillers such as alumina and boron nitride... achieves improved thermal conductivity
Implementation Method 2
at least one silicone base... a peroxide cross-linking agent
Implementation Method 3
at least one silicone oil... low hardness, high compression set resistance
Data Source
AI summary
A thermally conductive interface device produced from a thermally conductive interface material is disclosed. The device may be employed in a battery system of an electric or hybrid vehicle. The thermally conductive interface material comprises a composition of at least one silicone base, at least one inorganic filler, at least one silicone oil, a least one peroxide cross-linking agent, and/or at least one of a flame retardant and a colorant. The inorganic fillers and/or the silicone oils may be functionalized or non-functionalized. The silicone base may be a high consistency rubber (HCR) silicone.