Aerogel Heat Insulation Sheet for Battery Thermal Runaway and Expansion
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Solution Overview
Problem
Existing rechargeable lithium batteries face challenges in preventing heat propagation and pressure absorption during thermal runaway and cell expansion, which can lead to instability.
Innovation Solution
A heat insulation sheet for lithium batteries comprising a stack of aerogel-containing layers with fibrous supports and binders, including a first and third layer with fibrous supports and a second layer without, providing improved thermal insulation and compression properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a heat insulation sheet is used to prevent heat propagation between battery cells, then thermal safety is improved, but the sheet may not adequately absorb pressure during cell expansion
Solution Approach 1:
The heat insulation sheet uses a composite structure combining aerogel particles (for thermal insulation) with a porous polymer matrix (for pressure absorption). This composite material simultaneously achieves both heat propagation prevention and pressure absorption during cell expansion, resolving the contradiction between thermal safety and adaptability to mechanical stress.
Solution Approach 2:
The sheet employs porous aerogel particles embedded in a porous polymer matrix, creating a hierarchical porous structure. This structure provides both excellent thermal insulation properties and high compressibility, enabling the material to absorb pressure during cell expansion while maintaining thermal barrier functionality.
2Reliability
If a dense insulation material is used to block heat transfer, then thermal insulation performance is improved, but the material becomes rigid and cannot accommodate cell expansion
Solution Approach 1:
The use of porous aerogel particles with high porosity (typically 80-90%) creates a material that is both thermally insulating and mechanically flexible. The porous structure allows the material to compress and expand with battery cell volume changes while maintaining effective heat barrier properties.
Solution Approach 2:
The composite of rigid aerogel particles within a flexible polymer matrix creates a synergistic effect where the aerogel provides thermal insulation and the polymer matrix provides flexibility and elasticity, allowing the insulation sheet to accommodate cell expansion without compromising insulation performance.
3Reliability
If multiple functional layers are stacked to achieve both insulation and pressure absorption, then performance is improved, but device complexity increases
Solution Approach 1:
The heat insulation sheet is designed as a single multi-functional component that simultaneously provides thermal insulation, pressure absorption, and mechanical cushioning. This eliminates the need for separate insulation layers and cushioning layers, reducing structural complexity while maintaining or improving overall performance.
Solution Approach 2:
The patent merges the functions of thermal insulation and pressure absorption into a single integrated sheet structure. The aerogel-polymer composite combines the thermal barrier function with the mechanical compliance function, simplifying the battery module structure by eliminating the need for multiple separate functional layers.
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 heat insulation sheet effectively prevents heat transfer between battery cells and absorbs pressure during cell degradation, enhancing battery stability and durability.
Implementation Method 1
a heat insulation sheet for a rechargeable lithium battery... capable of preventing heat from propagating from one battery cell to an adjacent battery cell
Implementation Method 2
absorbs pressure of the adjacent cell during a cell degradation and expansion process by providing a high compression rate
Data Source
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AI summary
The present disclosure relates to a heat insulation sheet for a rechargeable lithium battery, and a rechargeable lithium battery module. The heat insulation sheet for a rechargeable lithium battery includes a first base layer, a first aerogel-containing layer, a second aerogel-containing layer, and a third aerogel-containing layer that are stacked together. The first aerogel-containing layer and the third aerogel-containing layer each include a fibrous support, an aerogel, and a binder, and the second aerogel-containing layer includes an aerogel and a binder.