Core-Sheath Polymer Membrane for Battery Thermal Stability
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Solution Overview
Problem
Conventional polymer membranes for batteries face challenges with mechanical strength, durability, and thermal stability, which affect their performance in fuel cells and rechargeable batteries, leading to issues like short circuits and degradation.
Innovation Solution
A polymer membrane with a core-sheath structure is developed, comprising a high melting-point polymer core and a low melting-point polymer sheath, along with a proton conductive polymer impregnated in a porous support, optimized through calendaring and hydrophilic treatments to enhance dimensional and thermal stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional polymer membrane is used for battery separation, then the membrane provides basic separation function, but the mechanical strength and thermal stability are insufficient leading to short circuits and degradation
Solution Approach 1:
The patent employs a composite membrane structure combining a porous support layer made of polyolefin fibers with a coating layer containing proton-conductive polymer and inorganic particles. This composite structure leverages the mechanical strength of the polyolefin support while the proton-conductive coating layer provides thermal stability and prevents short circuits, resolving the contradiction between mechanical strength and thermal stability.
Solution Approach 2:
The patent utilizes a porous support layer with controlled pore size and porosity to provide both mechanical integrity and thermal stability. The porous structure allows for electrolyte penetration while maintaining structural strength, and the inorganic particles within the coating layer further enhance thermal stability without compromising mechanical properties, thus resolving the contradiction between mechanical strength and thermal stability.
2Stability of the object's composition
If the polymer membrane structure is optimized for thermal stability, then dimensional stability improves, but manufacturing complexity increases
Solution Approach 1:
The patent applies preliminary actions by pre-forming the porous support layer with controlled pore structure and then coating it with the proton-conductive polymer mixture. The inorganic particles are pre-mixed with the polymer solution before coating, ensuring uniform distribution. This stepwise preliminary preparation simplifies the overall manufacturing process while achieving the desired dimensional stability through the structured composite architecture.
Solution Approach 2:
The patent optimizes dimensional stability by controlling key parameters such as pore size (0.01-10 μm), porosity (30-80%), and the ratio of proton-conductive polymer to inorganic particles in the coating layer. By adjusting these parameters within specific ranges, the membrane achieves excellent dimensional stability without requiring overly complex manufacturing processes, as the changes are made within conventional processing capabilities.
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 membrane exhibits improved dimensional and thermal stability, reduced ohmic loss, and increased ion conductivity, preventing short circuits and degradation, while maintaining mechanical properties and electrochemical stability.
Implementation Method 1
a core of a high melting-point polymer, and a sheath of a low melting-point polymer surrounding the core, wherein the melting point difference between the high melting-point polymer and the low melting-point polymer ranges from about 20° C. to about 160° C.
Implementation Method 2
a proton conductive polymer impregnated in a porous support
Data Source
AI summary
Disclosed is a polymer membrane for a battery including a porous support including a fiber including a core including a high melting-point polymer; and a sheath including a low melting-point polymer surrounding the core, and a method of preparing the same. The polymer membrane for a battery may further include a proton conductive polymer.