Composite Cathode Materials for Reversible High-Energy Batteries

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Solution Overview

Problem

Lithium-ion batteries have limitations in energy density, material costs, and electrochemical reversibility, with lithium-air batteries facing issues like oxygen desorption and thermal runaway due to irreversible byproducts.

Innovation Solution

Development of cathode active materials comprising a metal compound and metal oxide in contact, combined with an electrically-conductive material, which are synthesized using a hygroscopic species and reactive oxygen species, reducing oxygen evolution and enhancing electrochemical reversibility.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If lithium-air or lithium-oxygen batteries are used to achieve higher energy density, then energy density is improved, but oxygen desorption and thermal runaway occur due to electrochemically irreversible byproducts

Engineering Contradiction:

Improveenergy densityVSAvoidelectrochemical reversibility

Core Design Contradiction:

Use of energy by moving objectVSReliability

Solution Approach 1:

A protective coating layer is applied to the cathode structure to act as an intermediary barrier. This coating prevents direct contact between the reactive oxygen species and the cathode substrate, thereby suppressing oxygen desorption and irreversible byproduct formation while still allowing ionic transport for electrochemical reactions.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The cathode structure incorporates materials with specific electronic and ionic conductivity parameters optimized for reversible oxygen reactions. By adjusting the conductivity parameters and compositional ratios of the cathode materials, the system achieves better electrochemical reversibility while maintaining high energy density.

Inventive Principle:

Principle #35Parameter changes

2Use of energy by moving object

If lithium-air or lithium-oxygen batteries are used to achieve higher energy density, then energy density is improved, but thermal runaway reactions occur due to oxygen desorption

Engineering Contradiction:

Improveenergy densityVSAvoidthermal runaway

Core Design Contradiction:

Use of energy by moving objectVSObject-affected harmful factors

Solution Approach 1:

The cathode structure incorporates thermally stable materials and protective coatings that act as a cushion against thermal runaway. These pre-installed protective measures absorb and dissipate thermal energy before it can propagate, preventing thermal runaway even when oxygen desorption occurs during battery operation.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

A protective coating layer serves as a thermal barrier between the reactive oxygen species and the cathode substrate. This intermediary layer prevents direct exothermic reactions that would lead to thermal runaway, while still permitting the electrochemical reactions necessary for high energy density.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Use of energy by moving object

If conventional cathode materials are used to achieve high energy density, then energy density is improved, but material costs increase

Engineering Contradiction:

Improveenergy densityVSAvoidmaterial costs

Core Design Contradiction:

Use of energy by moving objectVSEase of manufacture

Solution Approach 1:

The cathode employs composite materials combining abundant, low-cost metals with carefully selected ratios to achieve high energy density without relying on expensive rare materials. The composite structure optimizes the synergistic effects of different materials to deliver high performance at reduced cost.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The invention optimizes the compositional parameters and ratios of cathode materials to achieve maximum energy density with minimal use of expensive components. By adjusting stoichiometric ratios and material compositions, the system delivers high energy density while using cost-effective, abundant materials.

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 approach results in high-energy density batteries with reduced material costs, improved reversibility, and minimized oxygen generation, leading to stable and efficient battery performance.

Implementation Method 1

heating the solution at a temperature that is less than about 400° C. for a time sufficient for a precipitate of the cathode active material to form

Methodology Applied

Scientific EffectHygroscopic absorption: Absorption (physical)

Implementation Method 2

heating the solution at a temperature that is less than about 400° C. for a time sufficient for a precipitate of the cathode active material to form

Methodology Applied

Scientific EffectPrecipitation: Precipitation

Data Source

PatentUS11804592B2High-energy cathodes, batteries, and methods of making the same

Publication Date: 2023.10.31 WATTRII INC

AI summary

Cathode active materials that include a metal compound having the formula MaRb, where M is a metal, each R is independently selected so that MaRb is an inorganic or organometallic compound or complex, and a and b are independently positive nonzero real numbers; and a metal oxide having the formula MxOy, where M is the same metal in the metal compound, and x and y are independently positive nonzero real numbers; provided that the metal compound and the metal oxide are in contact. The cathodes can be economically incorporated into batteries that can provide high energy density.