Dual-Layer Positive Electrode Material for Stable High-Voltage Output

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Solution Overview

Problem

Existing rechargeable lithium batteries face challenges in achieving high energy density, high average voltage, and excellent lifetime while maintaining economic viability.

Innovation Solution

A positive electrode active material comprising a combination of olivine-structured and layered-structured lithium compounds, with specific elemental compositions and particle sizes, is used to enhance energy density and voltage, and includes a layered structure with a larger average particle diameter to improve structural stability and conductivity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If a single-type positive electrode active material is used, then the electrode structure is simple, but the energy density and voltage characteristics are limited

Engineering Contradiction:

Improveenergy densityVSAvoidelectrode structure complexity

Core Design Contradiction:

Quantity of substanceVSDevice complexity

Solution Approach 1:

The patent combines two different positive electrode active materials (olivine-structured lithium compound and layered lithium compound) into a single electrode structure. This merging of different material types enables the electrode to achieve both high energy density from the layered compound and high voltage characteristics from the olivine compound, while maintaining a relatively simple overall electrode structure.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent uses a composite material system consisting of olivine-structured lithium compound (Li1-xMxCo1-yNiyFe0.1Mn0.8-yO4) and layered lithium compound (Li1-aTiaNi0.6Co0.1Mn0.3O2). The composite structure allows each material to contribute its unique properties, achieving synergistic effects that improve overall energy density and voltage characteristics beyond what either material could achieve alone.

Inventive Principle:

Principle #40Composite materials

2Quantity of substance

If high-nickel layered lithium compound is used to increase energy density, then the energy density improves, but the structural stability deteriorates

Engineering Contradiction:

Improveenergy densityVSAvoidstructural stability

Core Design Contradiction:

Quantity of substanceVSStability of the object's composition

Solution Approach 1:

The patent applies local quality by creating a core-shell structure where the layered lithium compound (high energy density) forms the core and the olivine-structured lithium compound (high stability) forms the outer shell. This local differentiation allows the inner core to provide high energy density while the outer shell provides structural stability and protection, resolving the contradiction between energy density and structural stability.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The olivine-structured lithium compound acts as a protective cushioning layer around the high-nickel layered lithium compound. This beforehand cushioning prevents structural degradation and instability that would otherwise occur in the high-nickel material during cycling, while still allowing the inner material to contribute its high energy density properties.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

3Reliability

If small particle size is used to improve conductivity, then the electrical conductivity improves, but the particle strength and structural stability worsen

Engineering Contradiction:

Improveelectrical conductivityVSAvoidparticle strength

Core Design Contradiction:

ReliabilityVSStrength

Solution Approach 1:

The patent creates a composite material system where small-particle layered lithium compound (high conductivity) is combined with olivine-structured lithium compound (high strength). The composite structure allows the small particles to provide excellent electrical conductivity while the overall composite maintains structural integrity and particle strength through the combined material system.

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 proposed electrode material achieves high energy density, high average voltage, and improved lifetime, while maintaining economic feasibility, by optimizing the structural and electrical properties of the lithium battery.

Implementation Method 1

produce electrical energy from redox reactions that take place as lithium ions are intercalated into or deintercalated from the positive electrode and the negative electrode

Methodology Applied

Scientific EffectRedox reactions: Redox Reactions

Data Source

PatentUS20250336950A1Positive electrode active material for rechargeable lithium battery, positive electrode including the same, and rechargeable lithium battery including the same

Publication Date: 2025.10.30 SAMSUNG SDI CO LTD

AI summary

Provided are a positive electrode for a rechargeable lithium battery and a rechargeable lithium battery including the same, and for example, a positive electrode for a rechargeable lithium battery, including a current collector, a first positive electrode active material layer on the current collector, and a second positive electrode active material layer on the first positive electrode active material layer. The first positive electrode active material layer includes a first particle having an olivine structure, and a second particle having a layered structure, and the second positive electrode active material layer includes a third particle having an olivine structure. The first particle and the third particle are each in the form of a single particle, and the second particle has a greater average particle diameter than each of the first particle and the third particle.