Reversible Thermal Release Mechanism for Battery Safety
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Lithium-ion batteries face risks of thermal runaway due to high energy density, leading to overheating, fire, and potential cascading failures in multi-cell battery packs, posing safety concerns particularly in large-scale and mission-critical applications.
Innovation Solution
The implementation of thermal dissipation and electrical isolation mechanisms, including a thermally conductive matrix with phase-change materials (PCMs) to absorb and distribute heat, and a reversible electrical isolation mechanism using a preloaded spring actuated by PCM melting, to prevent overheating and isolate failed cells, thereby preventing cascading thermal runaway.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If thermal isolation barriers are placed between battery cells to prevent thermal runaway propagation, then safety is improved, but heat dissipation capability deteriorates
Solution Approach 1:
The patent applies local quality by creating zones with different thermal properties: highly thermally conductive material directly surrounding each battery cell for heat dissipation, and thermally insulative material in the spaces between cells for isolation. This localized differentiation resolves the contradiction by optimizing both heat dissipation (at the cell level) and thermal isolation (at the pack level).
Solution Approach 2:
The patent uses composite materials combining thermally conductive fillers (such as aluminum oxide, aluminum nitride, or boron nitride) embedded in a matrix material to create intercellular structures that simultaneously provide thermal conduction pathways and structural support, enabling both heat dissipation and safety functions.
2Object-affected harmful factors
If a battery cell undergoes thermal runaway, then catastrophic failure occurs, but neighboring cells can be protected if isolation mechanisms are in place
Solution Approach 1:
The patent segments the battery pack into individual cell zones separated by intercellular spaces filled with insulative material. This segmentation creates physical and thermal barriers that prevent thermal runaway propagation from one cell to neighboring cells, while maintaining a relatively simple overall structure without complex active control systems.
3Temperature
If thermally conductive material is used to dissipate heat from battery cells, then heat dissipation capability is improved, but thermal isolation between cells deteriorates
Solution Approach 1:
The patent implements local quality by assigning different thermal conductivity characteristics to different spatial locations: high thermal conductivity material is placed immediately around each cell to facilitate heat dissipation, while low thermal conductivity material is placed in the intercellular spaces to provide thermal isolation. This spatial differentiation resolves the contradiction between heat dissipation and thermal isolation.
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 mitigates the risk of thermal runaway by distributing heat across the battery system, preventing overheating, and allowing the battery pack to continue operating without losing energy storage capability, with the potential for reversible operation and reduced risk of catastrophic failures.
Implementation Method 1
a phase-change material disposed in the cavity of the reservoir
Implementation Method 2
a preloaded spring actuated by PCM melting
Data Source
AI summary
A battery safety mechanism can provide a fast-action thermal mechanism to protect and/or electrically isolate a cell of a battery and thereby allow the cell to cool and preserve or elongate life of the battery. The mechanism can use a phase-change material (PCM) reservoir that can be selectively melted to permit actuation of a spring-loaded metal shunt. When actuated, the metal shunt can be placed into contact with terminals of the cell, thereby allowing the cell to be bypassed and be disabled. Thus, the device can electrically isolate the cell from the rest of the battery.