Battery Cell Barrier for Thermal Runaway Isolation
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Solution Overview
Problem
Portable electrical energy storage devices, such as lithium-ion batteries, face challenges in managing the risk of cell failure and subsequent combustion, particularly in multi-cell deployments, where thermal runaway can propagate to adjacent cells, posing a hazard to users.
Innovation Solution
The implementation of an electrical energy storage cell barrier that functions as a thermal isolator and shock absorber, comprising a thermal insulating material and an elastic material, to prevent the propagation of thermal energy and protect terminals from damage, while also containing combustion gases within a sealed oxygen-free housing to minimize ignition risks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If lithium-ion batteries are used for high energy density, then energy storage capacity is improved, but thermal stability and safety deteriorate due to flammable electrolyte and susceptibility to thermal runaway
Solution Approach 1:
The patent divides the battery pack into multiple cells arranged in series, with each cell separated by insulating barriers. This segmentation isolates thermal runaway events to individual cells, preventing propagation to other cells while maintaining high energy density through efficient space utilization.
Solution Approach 2:
The patent introduces ceramic-coated aluminum foil as an intermediary barrier between battery cells. This intermediary layer provides thermal insulation and physical separation, acting as a mediator that blocks heat transfer and prevents thermal runaway propagation while allowing the battery to maintain high energy density.
2Volume of moving object
If battery cells are placed in close proximity for compact design, then device size is reduced, but thermal runaway propagation risk increases to adjacent cells
Solution Approach 1:
The patent applies localized ceramic coating on aluminum foil barriers between specific battery cells. This local quality enhancement provides targeted thermal insulation exactly where needed between adjacent cells, preventing thermal propagation while minimizing the volume occupied by protective materials.
Solution Approach 2:
The patent uses a composite structure of ceramic-coated aluminum foil as a barrier material. The ceramic layer provides thermal insulation properties while the aluminum foil provides structural integrity and flexibility, creating a composite material that effectively blocks thermal runaway propagation in compact battery designs.
3Productivity
If thin polymer separators are used in battery cells, then manufacturing efficiency is improved, but susceptibility to short circuits from metal particles increases
Solution Approach 1:
The patent employs a composite separator structure with a thin polymer base layer for manufacturing efficiency, reinforced with a porous ceramic coating layer that acts as a physical barrier to metal particles. This composite structure maintains the thin profile needed for efficient manufacturing while adding short circuit protection through the ceramic barrier.
Solution Approach 2:
The patent uses porous ceramic material as a coating on the polymer separator. The porous structure allows lithium ion transport while the ceramic matrix physically blocks metal particles from creating short circuits, maintaining manufacturing efficiency with thin separators while improving reliability.
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 solution effectively reduces the likelihood of self-propagating failures and uncontrolled bursting by absorbing thermal energy and isolating combustion gases, thereby enhancing user safety and device stability during rare cell failure events.
Implementation Method 1
an electrical energy storage cell barrier that functions as a thermal isolator... comprising a thermal insulating material
Implementation Method 2
an elastic material... serving as a shock absorber to protect the electrical energy storage cells from damage resulting from an impact or other force
Implementation Method 3
containing combustion gases within a sealed oxygen-free housing to minimize ignition risks
Data Source
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AI summary
Electrical energy storage device for powering portable devices such as vehicles or consumer electronics includes barriers to minimize migration of thermal energy and propagation of combustion in the rare event that electrical energy storage cells fail, burst and ignite. A burst structure is provided to vent gas from the device in a desired direction in the event pressure within the device exceeds a maximum value. Biased vents permit gases emanating from a portable electrical energy storage cell within an electrical energy storage module to escape and isolate other electrical energy storage cells from the gases.