Porous Ceramic Battery Separator for Low Resistance and Thermal Stability
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Solution Overview
Problem
Conventional rechargeable battery cells face high resistance in their components, leading to inefficient energy storage and delivery, degradation of the battery separator, and potential overheating due to thermal instability, which reduces the cell's ability to consistently store and deliver electrical energy over its lifetime.
Innovation Solution
The use of ceramic layers with high porosity and high weight ratios of α-alumina or γ-alumina ceramic particles to binder, combined with a high glass transition temperature binder, results in battery separators with lower resistance, higher thermal stability, and increased capacity retention, capable of scavenging corrosive compounds like hydrogen fluoride.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If conventional battery separators are used, then the battery cell can be manufactured with standard components, but the resistance is high leading to inefficient energy storage and delivery
Solution Approach 1:
The patent applies composite materials by combining ceramic particles (alumina, silica, zirconia) with polymer matrix materials to create a hybrid separator structure. This composite approach reduces ionic resistance while maintaining mechanical integrity and thermal stability, directly addressing the energy loss issue without sacrificing reliability.
Solution Approach 2:
The patent utilizes porous materials by creating a separator with controlled porosity (30-70%) through the ceramic-polymer composite structure. The porous network facilitates efficient ion transport, reducing resistance and energy loss, while the ceramic framework maintains structural stability for consistent performance.
2Duration of action of stationary object
If standard battery separators are used, then the manufacturing process is simple, but the separator degrades over time reducing battery lifetime
Solution Approach 1:
The ceramic-polymer composite structure enhances separator durability and lifetime. The ceramic particles provide thermal stability and mechanical strength, preventing degradation over time, while the polymer matrix ensures flexibility and ion conductivity. This extended lifetime comes with increased structural complexity.
Solution Approach 2:
The patent modifies separator parameters by adjusting ceramic particle size distribution (bimodal or multimodal), porosity (30-70%), and composition ratios to optimize both lifetime and manufacturing feasibility. These parameter changes balance performance improvement with manufacturing complexity.
3Temperature
If conventional separators are used, then the battery cell structure is simple, but overheating occurs due to thermal instability
Solution Approach 1:
The ceramic-polymer composite provides superior thermal stability. Ceramic particles (alumina, silica, zirconia) have high melting points and maintain structural integrity at elevated temperatures, preventing thermal runaway. The polymer matrix provides flexibility but is stabilized by the ceramic framework, achieving thermal stability with increased design complexity.
Solution Approach 2:
The patent exploits thermal expansion properties by selecting ceramic materials with low thermal expansion coefficients that match or complement the polymer matrix. This minimizes thermal stress and deformation during temperature cycling, enhancing thermal stability while managing the complexity of material selection.
4Reliability
If high ceramic particle content is used, then thermal stability and capacity retention improve, but the manufacturing complexity increases
Solution Approach 1:
The patent optimizes manufacturing by controlling ceramic particle size distribution (bimodal or multimodal with specific D10, D50, D90 values) and porosity (30-70%). These parameter optimizations enable better packing density and uniformity, improving capacity retention while facilitating conventional manufacturing processes.
Solution Approach 2:
The patent applies local quality by using bimodal or multimodal particle size distributions where different particle sizes fulfill different functions. Smaller particles fill voids between larger particles, improving density and mechanical strength in critical regions, while larger particles provide structural framework. This localized optimization enhances performance without proportionally increasing manufacturing complexity.
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 ceramic layers provide battery cells with lower resistance, higher thermal stability, and improved capacity retention, maintaining over 90% of initial charge-discharge capacity after 300 cycles, while effectively absorbing hydrogen fluoride, thus enhancing battery performance and safety.
Implementation Method 1
A battery separator permits the transport of ionic charge carriers between a battery's electrodes
Implementation Method 2
the ceramic layer may be characterized by a porosity of greater than or about 40 vol %
Implementation Method 3
The battery component may include a binder, and the weight ratio of the ceramic particles to the binder may be greater than or equal to about 90:10
Implementation Method 4
the γ-alumina ceramic particles may be characterized by a hydrogen fluoride gas absorption capacity of greater than or about 5 mg HF per gram of the ceramic layer
Data Source
AI summary
A battery component is described that has at least one ceramic layer that includes ceramic particles and a binder. The ceramic particles may include α-alumina or γ-alumina. The ceramic layer may be characterized by a porosity of greater than or about 40 vol %. In additional embodiments, the one or more ceramic layers may have a weight ratio of ceramic particles to binder is greater than or about 90:10. The battery component may be a battery separator that is characterized by a MacMullin number of less than or about 40 and a thermal shrinkage of less than or about 1 vol. % after 1 hour at 140° C.