Solid Polymer Electrolytes With Surface-Modified Silica Dispersion

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Solution Overview

Problem

Conventional organic liquid electrolytes in lithium-ion batteries have limited electrochemical stability and are flammable, while solid polymer electrolytes suffer from poor ionic conductivity at room temperature, hindering their practical application, and hybrid polymer-inorganic electrolytes face issues like filler agglomeration and weak polymer-filler interaction.

Innovation Solution

Incorporating surface-modified colloidal silica nanoparticles into solid polymer electrolytes, particularly poly vinyl ethylene carbonate-based electrolytes, enhances ionic conductivity and improves cycle performance by ensuring even dispersion and strong polymer-filler interaction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If solid polymer electrolytes are used to replace conventional organic liquid electrolytes, then safety risks are reduced and electrochemical stability window is widened, but ionic conductivity at room temperature deteriorates

Engineering Contradiction:

ImprovesafetyVSAvoidionic conductivity

Core Design Contradiction:

ReliabilityVSQuantity of substance

Solution Approach 1:

The patent creates a composite electrolyte system by integrating surface-modified colloidal silica nanoparticles into the solid polymer electrolyte matrix. The silica nanoparticles with surface modifications (such as hydrophobic or lithiophobe groups) form a hybrid composite structure that enhances ionic conductivity while maintaining the safety and stability advantages of solid polymer electrolytes, achieving ionic conductivity above 10^-4 S cm^-1 at room temperature.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The patent applies local quality modification by specifically modifying the surface properties of colloidal silica nanoparticles rather than changing the entire electrolyte composition. The surface-modified silica particles create localized pathways or interfaces that facilitate ion transport, improving ionic conductivity at specific locations within the electrolyte matrix without compromising the overall solid polymer structure.

Inventive Principle:

Principle #3Local quality

2Quantity of substance

If inorganic fillers are added to polymer electrolytes to enhance ionic conductivity, then ionic conductivity is improved, but filler agglomeration and weak polymer-filler interaction occur

Engineering Contradiction:

Improveionic conductivityVSAvoiddispersion uniformity

Core Design Contradiction:

Quantity of substanceVSStability of the object's composition

Solution Approach 1:

The patent uses surface modifications on colloidal silica nanoparticles as intermediary layers between the inorganic silica particles and the polymer matrix. These surface modifications (such as hydrophobic groups or lithiophobe groups) act as mediators that improve the interaction between the filler and polymer, preventing agglomeration and ensuring uniform dispersion while enhancing ionic conductivity.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the surface parameters of the colloidal silica nanoparticles through chemical or physical modifications. By altering surface properties such as hydrophobicity or lithiophobe characteristics, the patent optimizes the interfacial interaction between filler and polymer, achieving stable dispersion and improved ionic conductivity without filler aggregation.

Inventive Principle:

Principle #35Parameter changes

3Strength

If conventional inorganic fillers are used in polymer electrolytes, then mechanical properties are enhanced, but weak interaction between fillers and polymers reduces performance

Engineering Contradiction:

Improvemechanical strengthVSAvoidpolymer-filler interaction

Core Design Contradiction:

StrengthVSReliability

Solution Approach 1:

The patent modifies surface parameters of the colloidal silica nanoparticles to enhance polymer-filler interaction. By introducing specific surface groups or modifications, the patent improves the chemical or physical affinity between the inorganic filler and polymer matrix, strengthening the interface while maintaining mechanical strength enhancements from the filler incorporation.

Inventive Principle:

Principle #35Parameter changes

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 use of surface-modified colloidal silica nanoparticles significantly improves ionic conductivity to above 10−4 S cm−1 at room temperature and enhances the cycle performance of lithium-ion batteries by preventing filler agglomeration and improving mechanical properties.

Implementation Method 1

ionic conductivity has been improved significantly at room temperature (>10−4 S cm−1 for ionic conductivity)

Methodology Applied

Scientific EffectIonic conductivity: Conduction (electrical)

Implementation Method 2

The silica may be modified by organic compounds including organic silicon compounds such as silane

Methodology Applied

Scientific EffectSurface modification: Adsorption

Data Source

PatentUS20250337008A1Solid polymer electrolytes for solid-state lithium metal secondary batteries

Publication Date: 2025.10.30 EVONIK OPERATIONS GMBH

AI summary

A silica composition can be used in preparation of solid polymer electrolytes, wherein the silica composition has a surface-modified colloidal silica dispersion, or an evaporated product of the dispersion. A polymer electrolyte precursor composition for preparation of a solid polymer electrolyte, use of the polymer electrolyte precursor composition in preparation of a solid polymer electrolyte, a method to in-situ prepare a solid polymer electrolyte, a method to improve performance of a lithium-ion battery, a solid polymer electrolyte, an electrochemical device and a device are also described.