Structural EV Battery Pack Using Cell Compression as Chassis Support
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Solution Overview
Problem
Current battery packs in electric vehicles have low volumetric efficiency and require redundant structures, leading to increased weight, reduced range, and compromised crashworthiness due to sub-optimal integration with the vehicle body-in-white structure.
Innovation Solution
A battery pack design that integrates rectangular battery cells between longitudinal sill members and transverse beams, applying a compressive force of 20-200 kN/m2, forming a structural component that replaces traditional vehicle floor structures, with optional compression members and air gaps for impact absorption, allowing for improved volumetric efficiency and reduced weight.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If traditional standalone battery pack design is used, then protective cage and separate mechanical structures are provided, but volumetric efficiency is low and vehicle weight is increased
Solution Approach 1:
The battery pack is merged with the vehicle body structure by integrating the protective cage with the chassis frame. The battery pack serves dual functions as both energy storage unit and structural component, eliminating redundant separate mechanical structures and improving volumetric efficiency while reducing overall vehicle weight
Solution Approach 2:
The battery pack is designed to perform multiple functions simultaneously: energy storage, protective cage function, and structural chassis component. This multi-functionality allows the same component to provide both operational and structural benefits, reducing the need for additional separate structures
2Reliability
If battery pack is designed as standalone unit with separate mechanical structures, then protective function is provided, but device complexity and redundant structures increase
Solution Approach 1:
The protective cage and battery pack are merged into a single integrated unit that forms part of the vehicle chassis. This combination maintains the protective function while eliminating the need for separate mechanical structures, thereby reducing device complexity
Solution Approach 2:
The integrated battery pack structure serves multiple purposes: it provides protective enclosure for the cells, acts as a structural chassis component, and integrates with the vehicle frame. This multi-functionality reduces the number of separate components needed while maintaining protective reliability
3Quantity of substance
If larger cell footprint is used to compensate for low volumetric efficiency, then energy capacity is maintained, but vehicle dimensions and stopping distance are increased
Solution Approach 1:
The battery cells are arranged in a three-dimensional configuration within the integrated pack structure, utilizing vertical stacking and multi-level arrangements. This dimensional optimization allows high energy capacity to be achieved within a compact footprint, avoiding increases in vehicle length or width
4Strength
If more structures are added to battery pack, then structural strength is improved, but weight and environmental impact increase
Solution Approach 1:
The battery pack structure is merged with the vehicle chassis, allowing the same components to provide both battery support and vehicle structural strength. This eliminates redundant structures and reduces overall weight while maintaining or improving structural performance
Solution Approach 2:
The battery pack components are designed to serve dual purposes: supporting the battery cells and providing structural reinforcement to the vehicle. This multi-functionality reduces the need for additional separate structural elements, thereby reducing weight while maintaining strength
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 integrated design enhances vehicle responsiveness, reduces weight, increases stopping distance, and improves crashworthiness by leveraging the battery pack as a structural element, while maintaining efficient energy absorption and thermal management.
Implementation Method 1
the front piece and the transverse member exerting a compressive force of between 20 and 200 kN/m2 on the cells in the length direction
Data Source
AI summary
A battery pack for use in an electric vehicle, includes two longitudinal sill members extending in a length direction L, interconnected at a front side by a transverse front piece and at a distance from the front piece by a transverse member. Two or more rows of battery cells are placed side by side between the sill members. The front piece and the transverse member exert a compressive force of between 20 and 200 kN/m2 on the cells in the length direction.