Alternating Battery Pack Thermal Runaway Mitigation
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Solution Overview
Problem
Large battery packs with densely arranged secondary batteries are prone to thermal runaway and explosions due to high energy density and close proximity, leading to potential ignition and secondary ignition or explosion of adjacent batteries.
Innovation Solution
A battery pack structure where secondary batteries with high energy density (e.g., lithium-metal oxide) and those with excellent thermal stability (e.g., lithium iron phosphate) are alternately arranged, with their widest surfaces in direct contact, to mitigate heat transfer and prevent thermal runaway.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If secondary batteries are densely arranged to increase capacity and reduce volume, then energy density and space utilization are improved, but thermal runaway risk and safety deteriorate due to close proximity enabling heat transfer
Solution Approach 1:
The patent segments the battery pack into distinct regions by alternating high-energy-density batteries with thermal-stable batteries. This segmentation creates spatial separation between high-risk batteries, effectively dividing the thermal propagation paths and reducing the likelihood of cascading failures while maintaining high overall energy density.
Solution Approach 2:
The patent introduces thermal-stable batteries (lithium iron phosphate) as intermediary elements between high-energy-density batteries. These intermediary batteries act as thermal barriers that can absorb or resist heat transfer, preventing direct thermal propagation between adjacent high-energy-density batteries while maintaining compact arrangement.
2Reliability
If heterogeneous batteries are alternately arranged to improve safety by blocking heat transfer, then thermal stability is improved, but device complexity increases due to multiple battery types and arrangement patterns
Solution Approach 1:
The patent applies local quality by assigning different functional characteristics to different battery types within the same pack. High-energy-density batteries (lithium-metal oxide) provide energy density in specific locations, while thermal-stable batteries (lithium iron phosphate) provide thermal protection in alternating positions. This localized functional differentiation achieves safety without requiring complete system redesign.
Solution Approach 2:
The patent changes the categorical parameter of battery chemistry composition by alternating between two distinct cathode materials. This parameter change creates inherent thermal zoning within the pack structure, where different chemical properties provide complementary functions (energy storage vs. thermal stability) without requiring additional protective components or complex control systems.
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 arrangement enhances safety by blocking heat transfer between high-energy-density batteries, reducing the risk of thermal instability, explosions, and improving the overall lifespan of the battery pack by mixing battery types.
Implementation Method 1
a second secondary battery having a second cathode material different from the first cathode material of the first secondary battery... to mitigate heat transfer and prevent thermal runaway
Data Source
AI summary
A battery pack including heterogeneous secondary batteries includes: a first battery set in which a plurality of first secondary batteries are stacked; and a second battery set in which a plurality of second secondary batteries are stacked, in which each of the first battery set and the second battery set is formed of a plurality, and the battery pack has an arrangement structure in which the plurality of first battery sets and the plurality of second battery sets are alternately stacked in one direction.