Round Lithium Manganese Oxide Particles for Battery Stability

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Solution Overview

Problem

Lithium manganese oxide (LMO) materials for lithium-ion batteries face challenges such as manganese dissolution and non-uniform current distribution due to their octahedron shape, leading to capacity fade and structural instability during cycling.

Innovation Solution

Preparation of lithium manganese oxide particles with a substantially round shape through calcining a lithium source and a manganese source in the presence of a catalyst, such as transition metals, to reduce manganese dissolution and enhance uniform current distribution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If LMO materials with octahedron shape are used, then manufacturing cost is reduced and rate performance is improved, but manganese dissolution occurs and cycling stability deteriorates

Engineering Contradiction:

Improvemanufacturing costVSAvoidcycling stability

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The patent applies spheroidality by transforming the conventional octahedron-shaped LMO particles into spherical particles through a two-step calcination process. The first calcination forms an intermediate phase, and the second calcination completes the spherical morphology. This curvature eliminates corner and edge sites that cause manganese dissolution, thereby improving cycling stability while maintaining manufacturing feasibility.

Inventive Principle:

Principle #14Spheroidality (Curvature)

2Speed

If LMO materials with octahedron shape are used, then high rate performance is achieved, but non-uniform current distribution occurs and structural integrity deteriorates

Engineering Contradiction:

Improverate performanceVSAvoidstructural integrity

Core Design Contradiction:

SpeedVSStability of the object's composition

Solution Approach 1:

The spherical morphology provides uniform current distribution across the particle surface during high-rate charging and discharging. The rounded shape eliminates stress concentration points at corners and edges, preventing structural degradation while maintaining high rate performance.

Inventive Principle:

Principle #14Spheroidality (Curvature)

Solution Approach 2:

The patent changes the morphological parameter from octahedron to sphere, which fundamentally alters the current distribution pattern and stress field during electrochemical cycling. This parameter change enables simultaneous achievement of high rate performance and structural integrity.

Inventive Principle:

Principle #35Parameter changes

3Loss of time

If conventional calcination method is used, then processing time is reduced, but particle shape control is insufficient and manganese dissolution increases

Engineering Contradiction:

Improveprocessing timeVSAvoidparticle shape control

Core Design Contradiction:

Loss of timeVSManufacturing precision

Solution Approach 1:

The first calcination step creates a precursor intermediate phase with controlled morphology that serves as the foundation for the final spherical structure. This preliminary action enables the second calcination to complete the spherical transformation more efficiently, achieving both shape precision and reasonable processing time.

Inventive Principle:

Principle #10Preliminary action

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 round-shaped LMO particles exhibit improved cycling stability and capacity retention, reducing stress and cracking, and maintaining structural integrity over conventional angular LMO particles.

Implementation Method 1

In the presence of a catalyst, calcining (i) a lithium source and a manganese source and/or (ii) a lithium and manganese source to form the lithium manganese oxide particles

Methodology Applied

Scientific EffectCatalysis: Catalysis

Implementation Method 2

calcining (i) a lithium source and a manganese source and/or (ii) a lithium and manganese source to form the lithium manganese oxide particles

Methodology Applied

Scientific EffectCalcination: Heat Treatment

Data Source

PatentUS20230155113A1Lithium manganese oxide particles and methods of making the same

Publication Date: 2023.05.18 GM GLOBAL TECHNOLOGY OPERATIONS LLC

AI summary

Lithium manganese oxide (LMO) particles having a substantially round shape and methods of preparing such LMO particles are provided herein. The method includes, in the presences of a catalyst, calcining (i) a lithium source and a manganese source and/or (ii) a lithium and manganese source to form the LMO particles. Examples of the lithium source include Li2CO3, LiOH, LiNO3, Li2O, and combinations thereof, and examples of the manganese source include MnO2, Mn3O4, and a combination thereof. The lithium and manganese source includes LixMn2O4, where 0.75≤x≤1.25. The catalyst includes one or more transition metal, such as a period 5 transition metal, a period 6 transition metal, a period 7 transition metal, and a combination thereof, an oxide of the one or more transition metal, a salt of the one or more transition metal, or a combination thereof.