Recessed Thermal Runaway Blanket for Cylindrical Battery Modules
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Solution Overview
Problem
Existing battery packs for vehicles face challenges in managing thermal runaway events, where a malfunctioning battery cell can cause adjacent cells to overheat, leading to a cascade of failures, and there is a need for efficient electrical connections and thermal management to minimize mass and volume while accommodating various cell configurations.
Innovation Solution
The battery module design includes cylindrical cells with electrically conductive busbars for efficient electrical connections and a thermal runaway protection blanket with recessed portions and thermally stable materials to contain and dissipate heat from vents, along with a cooling plate for temperature control, allowing for multiple configurations and minimizing interconnect resistance and mass.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of stationary object
If battery cells are arranged in a compact configuration to minimize volume, then the battery module volume is reduced, but thermal runaway can more easily propagate to adjacent cells
Solution Approach 1:
A thermal barrier material is positioned between adjacent battery cells to act as an intermediary that blocks heat transfer. This material creates a thermal isolation layer that prevents thermal runaway propagation while maintaining compact cell spacing for volume efficiency.
Solution Approach 2:
Thermal management properties are made non-uniform by placing thermal barrier materials specifically at locations between battery cells where heat propagation risk is highest. This localized approach provides thermal protection only where needed, rather than uniformly across the entire battery module.
2Reliability
If busbars are made larger to reduce electrical resistance, then electrical connection efficiency improves, but the battery module mass and volume increase
Solution Approach 1:
Busbars are constructed using composite material structures that combine highly conductive materials with lighterweight support structures. This allows achieving low electrical resistance without the mass penalty of traditionally oversized solid metal busbars.
Solution Approach 2:
The busbar design incorporates flexible or adjustable connection geometries that optimize electrical contact area and reduce resistance dynamically, allowing smaller overall busbar dimensions while maintaining connection efficiency.
3Reliability
If thermal barrier materials are placed between all battery cells to prevent thermal runaway, then safety improves, but the device complexity and manufacturing difficulty increase
Solution Approach 1:
Thermal barrier materials are applied selectively between only those battery cells that are most susceptible to thermal runaway propagation, rather than uniformly between all cells. This partial application achieves adequate safety while reducing structural complexity and manufacturing steps.
4Quantity of substance
If battery cells are arranged in multiple planes to increase energy density, then the energy storage capacity improves, but the difficulty of electrical connections and thermal management increases
Solution Approach 1:
Busbars are designed with multi-functional geometries that simultaneously provide electrical connection across multiple cell planes and serve as structural support elements. This universal design reduces the number of separate components needed for multi-plane configurations.
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
This design effectively contains thermal runaway events, reduces the risk of adjacent cell failures, and optimizes electrical connections for efficient energy transfer, while accommodating various cell configurations and sizes, enhancing the safety and performance of battery packs.
Implementation Method 1
a thermal runaway protection blanket with recessed portions and thermally stable materials to contain and dissipate heat from vents
Implementation Method 2
electrically conductive busbars that electrically connect the groups within the housing, that electrically connect positive terminals of the cylindrical battery cells of a first one of the groups with the positive terminal of the battery module
Data Source
AI summary
A battery module includes: positive and negative terminals disposed on an exterior of a housing of the battery module; groups of cylindrical battery cells, each of the battery cells of each group having a positive and negative terminals, and a vent; and electrically conductive busbars that electrically connect the groups, that electrically connect positive terminals of the battery cells of a first one of the groups with the positive terminal of the battery module, and that electrically connect negative terminals of the battery cells of a second one of the groups with the negative terminal of the battery module; and a thermal runaway protection blanket including: a first surface; a second surface opposite the first surface; and recessed portions that are recessed relative to the second surface and that extend toward the first surface, where the vents of at least a portion of the battery cells face the recessed portions.