Lithium Manganese Composite Oxide Coating for Battery Capacity and Durability

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Lithium ion secondary batteries face challenges with low discharge characteristics and durability due to the limitations of layered Li2MnO3-based Li-excess positive electrodes, which are costly and prone to capacity reduction over cycles.

Innovation Solution

A lithium manganese composite oxide with a metal-containing compound film and a carbon coating, where at least part of the surface is coated with a metal-containing compound and further coated with carbon, is used as a positive electrode material to improve discharge rate characteristics and cycle durability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If lithium cobalt oxide (LiCoO2) is used as positive electrode material, then battery capacity and performance are improved, but manufacturing cost increases due to high cobalt content

Engineering Contradiction:

Improvebattery capacityVSAvoidmanufacturing cost

Core Design Contradiction:

Quantity of substanceVSEase of manufacture

Solution Approach 1:

The patent changes the chemical composition parameters by using lithium nickel oxide (LiNiO2) or lithium manganese oxide (LiMn2O4) as substitutes for lithium cobalt oxide, thereby reducing cobalt content and manufacturing cost while maintaining acceptable battery capacity

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent employs inexpensive and abundantly available elements (nickel and manganese) to replace expensive cobalt, accepting that these materials may have shorter service life or require more frequent replacement

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

2Ease of manufacture

If lithium nickel oxide (LiNiO2) is used as substitute material, then manufacturing cost is reduced, but battery safety deteriorates during charge

Engineering Contradiction:

Improvemanufacturing costVSAvoidbattery safety

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The patent introduces a protective coating layer as an intermediary between the lithium nickel oxide particles and the electrolyte, preventing direct harmful interactions while allowing ionic transport, thus improving safety without sacrificing cost advantages

Inventive Principle:

Principle #24Intermediary (Mediator)

3Ease of manufacture

If lithium manganese oxide (LiMn2O4) is used as substitute material, then manufacturing cost is reduced, but battery characteristics deteriorate due to Mn dissolution at high temperature

Engineering Contradiction:

Improvemanufacturing costVSAvoidbattery characteristics

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The patent introduces a protective coating layer as an intermediary that prevents divalent Mn from dissolving into the electrolyte during charge and discharge at high temperature, thereby maintaining battery characteristics while keeping manufacturing costs low

Inventive Principle:

Principle #24Intermediary (Mediator)

4Quantity of substance

If layered Li2MnO3-based Li-excess positive electrode is used, then battery capacity is increased and cost is reduced, but discharge characteristics and durability deteriorate

Engineering Contradiction:

Improvebattery capacityVSAvoiddischarge characteristics and durability

Core Design Contradiction:

Quantity of substanceVSReliability

Solution Approach 1:

The patent optimizes the compositional parameters by controlling the ratios of lithium, manganese, and other metal elements in the composite oxide, achieving a balance between high capacity and good discharge characteristics/durability

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite material system combining lithium manganese composite oxide with other metal elements, where the synergistic effects of different components improve both discharge characteristics and durability while maintaining high capacity and low cost

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 lithium manganese composite oxide with a metal-containing compound film and carbon coating enhances discharge rate characteristics and suppresses capacity retention reduction after cycles, providing improved performance as a positive electrode material in lithium ion batteries.

Implementation Method 1

at least a part of the surface thereof is further coated with the carbon coating

Methodology Applied

Scientific EffectCarbon coating: Deposition (physical)

Implementation Method 2

at least a part of a surface of a lithium manganese composite oxide is coated with the metal-containing compound

Methodology Applied

Scientific EffectSurface coating with metal compound: Deposition (physical)

Data Source

PatentUS10637054B2Positive electrode material for lithium ion secondary batteries, and method for producing same

Publication Date: 2020.04.28 NEC CORP

AI summary

The present invention relates to a lithium manganese composite oxide having a metal-containing compound film and a carbon coating, in which at least a part of a surface of the lithium manganese composite oxide represented by Formula (1) is coated with the metal-containing compound film, and at least a part of the surface thereof is further coated with the carbon coating. The present invention can provide a positive electrode material capable of improving the discharge characteristics and the capacity retention rate after cycles of lithium ion secondary batteries.Li1+x(FeyNizMn1−y−z)1−xO2 (1),where 0<x<⅓, 0≤y, 0≤z<0.5, and y+z<1.