Lithium Battery Cathode Coated Fibers Mn Dissolution

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Solution Overview

Problem

Lithium-ion batteries face performance limitations due to cathode material degradation, particularly LiMn2O4 spinel, which experiences capacity reduction and structural instability due to Mn dissolution in the electrolyte, leading to reduced battery life and efficiency.

Innovation Solution

A high-speed fiber spinning method is used to form coated cathode fibers with a ZrO2 protective barrier layer, preventing Mn dissolution and stabilizing the spinel structure, thereby enhancing electrochemical cycling stability and lithium diffusivity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If LiMn2O4 spinel is used as cathode material, then cost is reduced and environmental benignity is improved, but capacity reduction and structural instability occur due to Mn dissolution

Engineering Contradiction:

ImprovecostVSAvoidstructural stability

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

A protective coating layer comprising Li2SiO3 and Li4SiO4 is formed on the surface of LiMn2O4 spinel particles. This coating acts as an intermediary barrier that prevents direct contact between the cathode material and electrolyte, thereby preventing Mn dissolution while maintaining the cost-effective LiMn2O4 spinel structure.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The surface composition and chemical properties of LiMn2O4 spinel are modified by forming a protective coating layer with different chemical composition (Li2SiO3 and Li4SiO4). This parameter change in surface chemistry prevents harmful interactions with electrolyte while preserving bulk material properties.

Inventive Principle:

Principle #35Parameter changes

2Ease of manufacture

If LiMn2O4 spinel is used as cathode material, then cost is reduced, but capacity fade increases due to Mn dissolution in electrolyte

Engineering Contradiction:

ImprovecostVSAvoidbattery life

Core Design Contradiction:

Ease of manufactureVSDuration of action of moving object

Solution Approach 1:

The protective coating layer of Li2SiO3 and Li4SiO4 serves as a mediator that isolates the LiMn2O4 spinel from the electrolyte, preventing Mn dissolution that would otherwise lead to capacity fade and reduced battery life, while maintaining the low-cost advantage.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The protective coating is formed on the cathode material surface before battery assembly, creating a pre-established barrier that prevents Mn dissolution and capacity fade from the outset, thereby extending battery life while maintaining cost-effectiveness.

Inventive Principle:

Principle #10Preliminary action

3Quantity of substance

If nanoparticle cathode materials are used, then specific capacity is improved, but surface degradation increases requiring protective coatings

Engineering Contradiction:

Improvespecific capacityVSAvoidsurface degradation

Core Design Contradiction:

Quantity of substanceVSObject-affected harmful factors

Solution Approach 1:

A protective coating layer comprising Li2SiO3 and Li4SiO4 is formed on the high-surface-area nanoparticle cathode material, acting as an intermediary that protects the reactive surface from degradation while preserving the high specific capacity benefits of the nanoparticle structure.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The cathode structure is designed as a composite material system combining LiMn2O4 spinel nanoparticles with a protective Li2SiO3/Li4SiO4 coating layer, where the core provides high specific capacity and the shell provides surface protection against degradation.

Inventive Principle:

Principle #40Composite materials

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 coated cathode fibers exhibit improved specific energy, electrochemical cycling stability, and chemical compatibility with the electrolyte, reducing capacity fade and maintaining battery performance over its lifetime while being cost-effective and environmentally benign.

Implementation Method 1

The fiber spinning forms the coated fibers from precursor polymer solutions formed by centrifugal forces and ambient atmospheric inertial drag

Methodology Applied

Scientific EffectCentrifugal force: Centrifugal Force

Implementation Method 2

A high-speed fiber spinning method is used to form coated cathode fibers with a ZrO2 protective barrier layer, preventing Mn dissolution and stabilizing the spinel structure

Methodology Applied

Scientific EffectPhysical barrier protection: Physical Containment

Implementation Method 3

Lithium batteries include a cathode formed from a compound able to reversibly intercalate and de-intercalate lithium ion

Methodology Applied

Scientific EffectIntercalation: Absorption (physical)

Implementation Method 4

The interfaces in cathode materials dictate numerous properties of electrode storage materials ranging from capacity loss, Li+ transport activation energy cost

Methodology Applied

Scientific EffectIon transport: Diffusion

Data Source

PatentUS11677071B2Lithium battery cathode

Publication Date: 2023.06.13 NATIONAL TECHNOLOGY & ENGINEERING SOLUTIONS OF SANDIA LLC

AI summary

A novel lithium battery cathode, a lithium ion battery using the same and processes and preparation thereof are disclosed. The battery cathode is formed by force spinning. Fiber spinning allows for the formation of core-shell materials using material chemistries that would be incompatible with prior spinning techniques. A fiber spinning apparatus for forming a coated fiber and a method of forming a coated fiber are also disclosed.