Solid Electrolyte Separator for Alkali-Metal-Ion Batteries
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Solution Overview
Problem
Current lithium-ion batteries face safety issues due to thermal run-away and flammability, primarily caused by flammable organic solvents, and existing solid electrolytes have low conductivity or undesirable physical characteristics, such as brittleness.
Innovation Solution
A substantially solid electrolyte separator is developed, comprising a first phase of poly(alkylene oxide) and an alkali-metal salt in a specific molar ratio, combined with ionically conductive particles and porous particles infiltrated with an organic solvent, to enhance ionic conductivity and flexibility, reducing the risk of thermal run-away and flammability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If flammable organic solvents are used in lithium-ion batteries, then ionic conductivity is improved, but safety deteriorates due to thermal run-away and flammability
Solution Approach 1:
The patent extracts and removes the flammable organic solvent component from the battery electrolyte system, replacing it with a solid electrolyte composed of poly(alkylene oxide) polymer matrix and lithium salt. This extraction eliminates the fire hazard while maintaining ionic conductivity through the solid polymer electrolyte structure.
Solution Approach 2:
The patent changes the physical state parameter of the electrolyte from liquid (organic solvent) to solid (polymer electrolyte). This parameter change transforms the electrolyte from a flammable liquid state to a non-flammable solid state, eliminating thermal run-away risks while preserving ionic transport capability through the polymer matrix.
2Object-affected harmful factors
If solid electrolyte separators are used to improve safety, then thermal run-away and flammability are reduced, but ionic conductivity deteriorates
Solution Approach 1:
The patent creates a composite solid electrolyte material combining poly(alkylene oxide) polymer matrix with lithium salt dispersed throughout. This composite structure provides both the safety benefits of solid electrolyte (non-flammable) and maintains ionic conductivity through the lithium salt pathways within the polymer matrix, achieving a balance between safety and performance.
3Use of energy by moving object
If ceramic electrolytes like LATP are used to achieve good conductivity, then ionic conductivity is improved, but mechanical properties deteriorate due to brittleness and inflexibility
Solution Approach 1:
The patent changes the material phase from crystalline ceramic (LATP) to amorphous polymer matrix. This parameter change transforms the material from a brittle solid to a flexible solid, eliminating the mechanical fragility issues while maintaining ionic conductivity through the polymer-Lithium salt composite structure.
Solution Approach 2:
The patent develops a composite polymer electrolyte that combines the ionic conductivity benefits of lithium salt with the mechanical flexibility of the poly(alkylene oxide) polymer matrix. This composite approach achieves both good ionic conductivity and desirable mechanical properties, avoiding the brittleness of pure ceramic electrolytes.
4Quantity of substance
If electrolyte separator is made very thin to increase energy density, then battery size is reduced, but structural integrity deteriorates
Solution Approach 1:
The patent employs a flexible polymer electrolyte membrane that can be manufactured as a thin film while maintaining structural integrity. The poly(alkylene oxide) polymer matrix provides inherent flexibility and toughness, allowing the electrolyte separator to be made very thin to increase energy density without sacrificing mechanical strength or risking catastrophic failure.
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 solution provides a safer, more flexible, and highly conductive electrolyte separator that increases the energy and power density of lithium-ion batteries while preventing dendritic shorts and cycle fade, making them suitable for various battery chemistries.
Implementation Method 1
an electrolyte separator for conducting alkali metal ions between the anode and the cathode. In selected embodiments, the electrolyte separator includes a first phase comprising poly(alkylene oxide) and an alkali-metal salt
Implementation Method 2
The electrolyte separator may further include a second phase comprising ionically conductive particles that are conductive to the alkali metal ions
Implementation Method 3
The electrolyte separator may further include a third phase comprising porous particles infiltrated with an organic solvent
Data Source
AI summary
An alkali-metal-ion battery is disclosed in one embodiment of the invention as including an anode containing an alkali metal, a cathode, and an electrolyte separator for conducting alkali metal ions between the anode and the cathode. In selected embodiments, the electrolyte separator includes a first phase comprising poly(alkylene oxide) and an alkali-metal salt in a molar ratio of less than 10:1. The electrolyte separator may further include a second phase comprising ionically conductive particles that are conductive to the alkali metal ions. These ionically conductive particles may include ionically conductive ceramic particles, glass particles, glass-ceramic particles, or mixtures thereof.