Polymer Composite Membrane for Lithium-Ion Battery Thermal Stability
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Solution Overview
Problem
Conventional lithium-ion battery membranes face challenges in balancing mechanical strength and high-temperature resistance stability, with existing methods either compromising on cost or performance.
Innovation Solution
A polymer composite membrane is developed, comprising a polymer base membrane with sequential layers of a ceramic layer, a heat-resistant fiber layer, and a bonding layer, where the heat-resistant fiber layer is formed using a spinning solution containing polymeric materials with specific melting points and liquid absorption rates to enhance thermal stability and mechanical strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the melt-spinning and cold-stretching method is used to prepare the membrane, then the mechanical strength and cost are improved, but the high-temperature resistance stability deteriorates
Solution Approach 1:
The patent applies composite materials by combining polyolefin base membrane with ceramic particles (alumina, silica, or boehmite) and heat-resistant polymer coatings. This composite structure integrates the mechanical strength of polyolefin with the thermal stability of ceramic particles and heat-resistant polymers, resolving the contradiction between mechanical strength and high-temperature resistance.
Solution Approach 2:
The patent changes the thermal parameters of the membrane by incorporating ceramic particles with high melting points and applying heat-resistant polymer coatings with glass transition temperatures above 100°C. These parameter changes enable the membrane to maintain structural integrity at elevated temperatures while preserving the base membrane's mechanical properties.
2Temperature
If the thermally induced phase separation method is used to prepare the membrane, then the high-temperature resistance stability is improved, but the mechanical strength and cost deteriorate
Solution Approach 1:
The patent uses composite materials where ceramic particles are embedded in the polyolefin matrix and heat-resistant polymer coatings are applied on the surface. This composite approach provides the high-temperature resistance needed to replace thermally induced phase separation membranes while maintaining mechanical strength through the robust polyolefin-ceramic-coating structure.
Solution Approach 2:
The patent applies local quality by concentrating heat-resistant components (ceramic particles and heat-resistant polymer coatings) specifically at the membrane surface and interface regions where thermal stress is highest. This localized enhancement provides high-temperature resistance without compromising the overall mechanical strength of the entire membrane structure.
3Temperature
If ceramic particles are added to the membrane, then the high-temperature resistance is improved, but the ion conductivity may deteriorate
Solution Approach 1:
The patent employs porous materials by using ceramic particles with controlled pore structures and maintaining a porous membrane architecture. The ceramic particles are distributed within the porous polyolefin matrix, allowing electrolyte penetration and ion transport through the pore network while the ceramic particles provide thermal stability. This porous structure ensures that ion conductivity is maintained despite the presence of ceramic particles.
Solution Approach 2:
The patent applies local quality by concentrating ceramic particles in specific regions of the membrane where thermal reinforcement is most needed, while maintaining pore continuity and electrolyte access in ion transport pathways. This selective distribution ensures that ceramic particles enhance high-temperature resistance without blocking ion conduction channels.
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 polymer composite membrane exhibits improved high-temperature resistance, mechanical strength, and ion conductivity, reducing the risk of electrode short-circuiting and enhancing the overall performance and safety of lithium-ion batteries.
Implementation Method 1
a liquid absorption rate of the second polymeric material in an electrolyte at 25° C. is above 40% and has an error of ±5%
Implementation Method 2
allowing ions of the electrolyte to pass freely, to complete an electrochemical charge/discharge process
Data Source
AI summary
The disclosure provides a polymer composite membrane, a method for preparing same, and a lithium-ion battery including same. The polymer composite membrane includes a polymer base membrane, where the polymer base membrane includes a first surface and a second surface disposed opposite to each other, and the polymer composite membrane further includes a first ceramic layer, a first heat-resistant fiber layer, and a first bonding layer disposed sequentially from inside out on the first surface of the polymer base membrane, where materials of the first heat-resistant fiber layer contain a first polymeric material and a second polymeric material.