Modified Endothermic Particles for Battery Heat Suppression
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Solution Overview
Problem
Non-aqueous electrolyte rechargeable batteries, such as lithium ion batteries, face challenges in maintaining internal temperature safety, particularly during high-temperature environments or abnormal conditions like internal short circuits, where existing endothermic particles fail to sufficiently suppress temperature increases, leading to potential separator melting and positive electrode decomposition.
Innovation Solution
The introduction of endothermic particles with modified carbon-containing functional groups, characterized by specific surface areas and desorption amounts of gases, which are treated with agents like silane coupling agents, are incorporated into the battery's positive electrode, negative electrode, separator, or electrolyte to manage temperature effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If conventional endothermic particles are used to suppress temperature increase, then temperature control is attempted, but the internal temperature cannot be sufficiently suppressed and separator melting occurs
Solution Approach 1:
The patent applies parameter changes by carefully controlling the particle size distribution (D10, D50, D90 values) and surface area-to-volume ratio of the endothermic particles. By optimizing these physical parameters, the particles achieve more effective heat absorption within the critical temperature range of 150-300°C, preventing separator melting while maintaining battery safety.
Solution Approach 2:
The patent uses composite materials by combining endothermic particles with specific surface treatments or coatings. This composite structure enhances the heat absorption capacity and ensures that the particles remain dispersed uniformly in the battery, improving their effectiveness in suppressing temperature increases compared to conventional pure endothermic particles.
2Temperature
If endothermic particles are added to suppress temperature, then temperature control is attempted, but separator melting and positive electrode decomposition occur
Solution Approach 1:
The patent applies preliminary action by incorporating endothermic particles that activate at specific temperature thresholds before the separator melting point is reached. The particles begin absorbing heat at 150-300°C, which is below the separator melting temperature, thereby preventing the harmful effects of separator melting and electrode decomposition by acting in advance.
Solution Approach 2:
The patent converts the harmful effect of heat generation into a beneficial effect by using the endothermic particles to absorb the excess heat through their own phase change or chemical reaction. The heat that would otherwise cause separator melting is instead consumed by the endothermic particles, transforming a harmful thermal condition into a controlled protective mechanism.
3Temperature
If high surface area endothermic particles are used, then heat absorption capacity is improved, but particle aggregation occurs reducing effectiveness
Solution Approach 1:
The patent applies this principle by coating the endothermic particles with thin film materials that prevent aggregation while maintaining high surface area. The coating acts as a protective shell that keeps particles dispersed uniformly in the battery electrolyte, preventing clumping that would reduce heat absorption effectiveness while preserving the high surface area-to-volume ratio needed for rapid heat absorption.
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
These modified endothermic particles effectively suppress internal temperature increases during abnormalities, enhancing battery safety and maintaining cycle life by ensuring a controlled endothermic reaction within a suitable temperature range.
Implementation Method 1
endothermic particles having a maximum endothermic peak temperature in DSC of greater than or equal to about 60° C. and less than or equal to about 300° C.
Implementation Method 2
an amount of desorbed CH4 (MS1) from about 80° C. to about 1400° C. by thermal desorption gas mass spectrometry (TDS-MS) of the metal hydroxide particles
Data Source
AI summary
Endothermic particles for a non-aqueous electrolyte rechargeable battery include at least partially modified metal hydroxide particles, wherein an amount of desorbed CH4 from about 80° C. to about 1400° C. by thermal desorption gas mass spectrometry (TDS-MS) of the metal hydroxide particles is between about 15×10−6 mol/g and about 3000×10−6 mol/g, an amount of desorbed CH3OH from about 80° C. to about 1400° C. by TDS-MS is between about 15×10−6 mol/g and about 6000×10−6 mol/g, an amount of desorbed H2O from about 80° C. to about 200° C. by TDS-MS is between about 30×10−6 mol/g and about 1500×10−6 mol/g, and a specific surface area of the metal hydroxide particles calculated by an adsorption isotherm measured by adsorbing water vapor or nitrogen to the metal hydroxide particles is between about 8 m2/g and about 600 m2/g.