Composite Solid Electrolyte with Polymer Coating for Lithium Batteries

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Solution Overview

Problem

Current solid electrolytes for lithium batteries, such as Li3N, fail to provide a suitable combination of high lithium ion conductivity and stability, leading to safety issues like short circuits due to lithium dendrite growth and limited lifespan.

Innovation Solution

A composite solid electrolyte is developed, comprising a lithium ion conductive solid electrolyte with a polymer-containing electrolyte coating layer having an alkylene oxide segment, which reduces interfacial resistance and enhances ionic conductivity and electrochemical stability by suppressing lithium dendrite growth.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a lithium ion conductive solid electrolyte is used, then high lithium ion conductivity is achieved, but stability deteriorates leading to safety issues and limited lifespan

Engineering Contradiction:

ImprovestabilityVSAvoidlifespan

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The patent applies composite materials by combining a lithium ion conductive solid electrolyte with a polymer-containing electrolyte coating layer. The solid electrolyte provides high ionic conductivity while the polymer coating layer enhances stability and suppresses lithium dendrite growth, resolving the contradiction between conductivity and stability/lifespan

Inventive Principle:

Principle #40Composite materials

2Reliability

If a solid electrolyte coating layer is added to improve stability, then electrochemical stability is enhanced, but interfacial resistance increases

Engineering Contradiction:

Improveelectrochemical stabilityVSAvoidinterfacial resistance

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent uses parameter changes by selecting specific polymer materials with appropriate molecular weight, composition, and coating thickness. The polymer-containing electrolyte coating layer is designed with controlled parameters to reduce interfacial resistance while maintaining electrochemical stability, resolving the contradiction between stability and interfacial resistance

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 composite solid electrolyte significantly decreases interfacial resistance and maintains high ionic conductivity at room temperature, ensuring stable lithium battery operation and preventing dendrite formation, thus improving safety and lifespan.

Implementation Method 1

the polymer-containing electrolyte coating layer includes an ion conductive polymer having an alkylene oxide segment

Methodology Applied

Scientific EffectIonic conduction: Conduction (electrical)

Implementation Method 2

enhances ionic conductivity and electrochemical stability by suppressing lithium dendrite growth

Methodology Applied

Scientific EffectElectrochemical stability:

Data Source

PatentUS10892518B2Composite solid electrolyte, protected anode and lithium battery including the same, and method of preparing the composite solid electrolyte

Publication Date: 2021.01.12 SAMSUNG ELECTRONICS CO LTD

AI summary

A composite solid electrolyte includes: a lithium ion conductive solid electrolyte; and a polymer-containing electrolyte coating layer on a surface of a lithium ion conductive solid electrolyte, wherein the polymer-containing electrolyte coating layer includes an ion conductive polymer having an alkylene oxide segment.