Phase-Change Current Collector for Battery Thermal Runaway
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Solution Overview
Problem
Thermal runaway in lithium-ion batteries is a frequent safety issue, and current solutions that improve the four major materials to control thermal runaway result in a loss of electrical performance and energy density.
Innovation Solution
A current collector with an organic substrate layer made of a phase-change material, such as polypropylene, that undergoes a phase change at a controlled initial melting temperature below the thermal runaway temperature of the battery, absorbing heat to reduce the risk of thermal runaway.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the four major materials are improved to control thermal runaway, then thermal safety is improved, but electrical performance and energy density are lost
Solution Approach 1:
The current collector substrate layer utilizes phase transition (melting) of the polymer material at a specific temperature range (100-160°C) to absorb excess heat from thermal runaway, providing passive thermal protection without requiring changes to the four major materials that would compromise energy density
Solution Approach 2:
The invention changes the temperature parameter at which thermal protection activates by selecting polymer materials with specific melting points (100-160°C), allowing thermal runaway control at lower temperatures before dangerous thermal propagation occurs, thereby maintaining the performance of the four major materials
2Reliability
If polymer material with low melting point is used for heat absorption, then thermal runaway risk is reduced, but structural stability may deteriorate
Solution Approach 1:
The current collector is designed as a composite structure combining a polymer substrate layer (providing thermal protection through phase transition) with metal conductive layers (providing structural stability and electrical conductivity), allowing each material to fulfill its optimal function without compromising the other
Solution Approach 2:
The polymer substrate layer undergoes controlled phase transition (melting) at 100-160°C to absorb thermal runaway heat, while the metal conductive layers maintain structural integrity at these temperatures, creating a synergistic thermal protection system
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 current collector effectively cools the battery by absorbing heat during phase change, reducing the risk of thermal runaway while maintaining electrical performance and energy density.
Implementation Method 1
the first polymer material is a phase-change material. An initial melting temperature of the first polymer material is not higher than 160° C.
Implementation Method 2
the current collector can absorb heat after reaching the initial melting temperature. When an operating temperature of the electrochemical apparatus reaches the initial melting temperature of the material of the organic substrate layer, the organic substrate layer experiences a phase change to absorb cell heat
Data Source
AI summary
A current collector includes an organic substrate layer and conductive layers disposed on two surfaces of the organic substrate layer. An initial melting temperature and phase change latent heat of a material of the organic substrate layer of the current collector are controlled so that the current collector can absorb a large amount of heat after reaching the initial melting temperature.