Electrode Assembly Thermal Barrier for Battery Heat Spreading
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Solution Overview
Problem
Secondary batteries face risks of thermal runaway due to rapid heat spreading during mechanical, electrical, or thermal abuse, leading to failure and potential fires, as existing electrode assemblies lack effective thermal barriers to manage heat transfer.
Innovation Solution
The electrode assembly incorporates a current collector configured as a thermal barrier with controlled thermal conductivity and thickness, specifically designed to reduce heat flux density and increase thermal resistance, using materials like bronze, iron, or stainless steel, to prevent rapid heat transfer and maintain high energy density.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a current collector is configured as a thermal barrier with controlled thermal conductivity and thickness, then heat spreading is reduced and thermal resistance is increased, but the structural complexity of the electrode assembly increases
Solution Approach 1:
The current collector is designed with non-uniform thickness, creating regions of different thermal resistance within the same component. Thinner regions allow heat dissipation while thicker regions provide thermal barrier functionality, enabling localized thermal management without adding separate components
Solution Approach 2:
The current collector serves dual functions: maintaining electrical conductivity for current collection and providing thermal barrier properties through controlled thickness variations. This multi-functionality eliminates the need for separate thermal barrier layers, reducing structural complexity while achieving thermal management
2Object-affected harmful factors
If the thermal conductivity of the barrier is reduced to form an effective thermal barrier, then heat flux density is reduced and thermal resistance is increased, but the electrical conductivity of the current collector may be compromised
Solution Approach 1:
The current collector features spatially varying thickness where thinner regions provide low thermal resistance for heat dissipation and thicker regions provide high thermal resistance for thermal barrier effects. This local differentiation allows simultaneous optimization of thermal and electrical properties in different zones
Solution Approach 2:
The current collector can be constructed as a composite structure combining materials with different thermal and electrical conductivity characteristics, or as a single material with non-uniform geometry, achieving the desired balance between thermal barrier performance and electrical conductivity
3Object-affected harmful factors
If the thickness of the barrier is increased to improve thermal resistance, then heat spreading is reduced, but the energy density of the battery decreases
Solution Approach 1:
Rather than uniformly increasing barrier thickness throughout the electrode assembly, the invention applies thicker barrier sections only where thermal management is most critical, while maintaining thinner sections in other areas to preserve active material volume and energy density
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 configuration effectively slows down heat spreading, reduces the risk of thermal runaway, and triggers safety mechanisms earlier, enhancing the safety and stability of secondary batteries by creating a robust thermal barrier within the electrode assembly.
Implementation Method 1
the thermal conductivity of the barrier in the thickness direction of the electrode assembly being denoted as λ0, and the thickness of the barrier being denoted as d0, with λ0/d0<3×107 watts per square meter Kelvin (W/(K*m2))
Data Source
AI summary
An electrode assembly, a secondary battery, a battery pack, and an electrical apparatus. In the electrode assembly, there are several electrode plate portions sequentially arranged in a laminated manner along its own thickness direction. During structural design, the current collector in at least one of the electrode plate portions is configured as a barrier, and by controlling the ratio between the thermal conductivity λ0 of the barrier and the thickness d0 of the barrier to be less than 3×107 W/(K*m2), the heat flux density of the barrier along the thickness direction of the electrode assembly is reduced and the thermal resistance is increased, thus forming an effective thermal barrier in the thickness direction of the electrode assembly.