Core-Shell Nickel-Manganese Precursor for Cobalt-Free Lithium Batteries

Solution Overview

Problem

Cobalt-free positive active materials with a layered structure for lithium batteries face structural instability and performance degradation due to the absence of cobalt, leading to reduced cycle-life and capacity, as cobalt plays a crucial role in maintaining the material's structure and performance.

Innovation Solution

A core-shell particle structure is developed for the positive active material, where the core consists of a nickel-manganese-based composite hydroxide and the shell includes a nickel-manganese-based composite hydroxide with a pillar element such as aluminum, molybdenum, titanium, or tungsten, which maintains structural stability and prevents collapse during charging and discharging.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If cobalt is removed or reduced from positive active materials, then cost is reduced and supply shortage is avoided, but structural defects occur causing resistance increases and performance decreases

Engineering Contradiction:

Improvecobalt contentVSAvoidstructural stability

Core Design Contradiction:

Quantity of substanceVSReliability

Solution Approach 1:

The patent applies local quality by creating a core-shell structure where the shell layer contains aluminum and other elements that provide structural stability, while the core contains high-nickel content for high capacity. This localized functional distribution allows cobalt reduction overall while maintaining structural integrity in critical regions.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent uses composite materials by combining nickel-manganese hydroxide with aluminum and other elements in a core-shell configuration. This composite structure provides both the high capacity needed from nickel-rich regions and the structural stability from aluminum-containing regions, eliminating the need for cobalt.

Inventive Principle:

Principle #40Composite materials

2Quantity of substance

If cobalt-free positive active materials with layered structure are developed, then cost is reduced, but capacity and performance deteriorate compared to cobalt-containing materials

Engineering Contradiction:

Improvecobalt contentVSAvoidbattery capacity

Core Design Contradiction:

Quantity of substanceVSProductivity

Solution Approach 1:

The shell layer is designed with specific composition (nickel-manganese-aluminum hydroxide) that maintains layered structure stability, enabling high capacity performance without cobalt. The local aluminum enrichment in the shell prevents structural degradation while preserving electrochemical activity.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent changes key parameters including the oxidation state of nickel (maintaining Ni2+ to prevent unwanted reactions), the ratio of metal elements, and the thickness composition of core and shell layers. These parameter optimizations enable cobalt-free materials to achieve capacity comparable to or exceeding cobalt-containing materials.

Inventive Principle:

Principle #35Parameter changes

3Stability of the object's composition

If nickel ions are maintained as Ni2+ in nickel-manganese layered positive active materials, then structural stability is improved, but performance deteriorates due to reduced capacity

Engineering Contradiction:

Improvestructural stabilityVSAvoidbattery capacity

Core Design Contradiction:

Stability of the object's compositionVSProductivity

Solution Approach 1:

The patent applies local quality by creating a core-shell structure where the shell layer contains aluminum and other elements that provide structural stability, while the core contains high-nickel content for high capacity. This localized functional distribution allows cobalt reduction overall while maintaining structural integrity in critical regions.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent uses composite materials by combining nickel-manganese hydroxide with aluminum and other elements in a core-shell configuration. This composite structure provides both the high capacity needed from nickel-rich regions and the structural stability from aluminum-containing regions, eliminating the need for cobalt.

Inventive Principle:

Principle #40Composite materials

Data Source

PatentUS20230101381A1Positive active material precursor for rechargeable lithium battery, method for preparing positive active material using the precursor, and positive active material for rechargeable lithium battery

Publication Date: 2023.03.30 SAMSUNG SDI CO LTD

AI summary

A positive active material precursor for a rechargeable lithium battery, a method for preparing a positive active material using the same, and a positive active material for a rechargeable lithium battery are provided. The positive active material precursor for a rechargeable lithium battery has a form of a core-shell particle including a core and a shell around the core, where the core includes a nickel-manganese-based composite hydroxide containing nickel and manganese, the shell includes a nickel-manganese-based composite hydroxide containing nickel, manganese, and a pillar element, and the pillar element includes at least one selected from Al, Mo, Ti, W, and Zr.