Solid Electrolyte Coated Membrane for Lithium-Sulfur Battery

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Solution Overview

Problem

Lithium-sulfur batteries and lithium ion batteries face limited life cycles due to polysulfide migration and transition metal cation diffusion, leading to decreased sulfur utilization, self-discharge, and reduced Coulombic efficiency, as well as electrode poisoning, which reduces their useful life.

Innovation Solution

A flexible membrane with a solid electrolyte coating, formed from a porous membrane coated with a polymer or inorganic ionically conductive material, is used to prevent polysulfide shuttling and transition metal cation migration by creating electrostatic repulsion and physical barriers within the battery.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a porous membrane is used as a separator in lithium-sulfur batteries, then ion transport is facilitated, but polysulfide migration occurs leading to decreased sulfur utilization and reduced Coulombic efficiency

Engineering Contradiction:

ImproveCoulombic efficiencyVSAvoidsulfur utilization

Core Design Contradiction:

ReliabilityVSLoss of substance

Solution Approach 1:

A solid electrolyte coating is applied to the porous membrane to act as an intermediary layer. This coating selectively blocks polysulfide migration while maintaining lithium ion transport, thereby preventing sulfur loss and improving Coulombic efficiency without compromising ion conductivity

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent utilizes a porous membrane structure that allows lithium ion transport while incorporating a solid electrolyte coating within the pores. The porous structure facilitates ion movement whereas the coating material prevents polysulfide shuttling, resolving the contradiction between ion transport and polysulfide blocking

Inventive Principle:

Principle #31Porous materials

2Power

If transition metal cations are present in the battery, then electrochemical reactions occur, but cation diffusion leads to electrode poisoning and reduced battery life

Engineering Contradiction:

Improveelectrochemical reactivityVSAvoidbattery life cycle

Core Design Contradiction:

PowerVSDuration of action of stationary object

Solution Approach 1:

The solid electrolyte coating serves as a mediator that allows necessary electrochemical reactions to proceed while blocking the diffusion of transition metal cations. This prevents electrode poisoning and extends battery life without significantly impeding power output

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The coating is applied locally to the membrane surface and within pores, creating zones with different properties: the coating layer blocks cation diffusion and prevents poisoning, while the porous membrane structure maintains electrochemical reactivity. This local differentiation resolves the contradiction between reactivity and longevity

Inventive Principle:

Principle #3Local quality

3Duration of action of stationary object

If no solid electrolyte coating is applied, then the battery structure remains simple, but polysulfide shuttling causes self-discharge and limited life cycle

Engineering Contradiction:

Improvelife cycleVSAvoidmembrane structure

Core Design Contradiction:

Duration of action of stationary objectVSDevice complexity

Solution Approach 1:

A thin solid electrolyte coating is applied to the porous membrane, creating a flexible barrier that prevents polysulfide shuttling and self-discharge. The thin film structure adds minimal complexity while dramatically extending battery life cycle through effective polysulfide blocking

Inventive Principle:

Principle #30Flexible shells and thin films

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 solid electrolyte coating enhances battery cyclability, sulfur utilization, and Coulombic efficiency, effectively extending the life cycle and preventing electrode poisoning, thereby improving the overall performance and longevity of lithium-sulfur and lithium ion batteries.

Implementation Method 1

prevent polysulfide shuttling and transition metal cation migration by creating electrostatic repulsion and physical barriers within the battery

Methodology Applied

Scientific EffectElectrostatic repulsion: Electrostatics

Implementation Method 2

prevent polysulfide shuttling and transition metal cation migration by creating electrostatic repulsion and physical barriers within the battery

Methodology Applied

Scientific EffectPhysical barrier: Physical Containment

Implementation Method 3

The solid electrolyte coating includes i) a polymer chain or ii) an inorganic ionically conductive material

Methodology Applied

Scientific EffectIonic conduction: Conduction (electrical)

Data Source

PatentUS9742028B2Flexible membranes and coated electrodes for lithium based batteries

Publication Date: 2017.08.22 GM GLOBAL TECHNOLOGY OPERATIONS LLC

AI summary

An example of a flexible membrane includes a porous membrane and a solid electrolyte coating formed on at least a portion of a surface of the porous membrane, in pores of the porous membrane, or both on the surface and in the pores. The solid electrolyte coating includes i) a polymer chain or ii) an inorganic ionically conductive material. The polymer chain or the inorganic material includes a group to interact or react with a polysulfide through covalent bonding or supramolecular interaction.