High-Nickel Positive Electrode Material for Battery Energy Density

Solution Overview

Problem

Current high-nickel ternary positive electrode materials face challenges in achieving high compacted density and energy density due to particle crushing during cold pressing and cycling, leading to gassing issues and poor cycle performance.

Innovation Solution

A positive electrode material comprising a combination of large-particle lithium-nickel transition metal oxide A and small-particle lithium-nickel transition metal oxide B, with controlled crystallinity and particle size distribution, is developed to mitigate particle crushing and enhance compacted density, energy density, and cycle performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If high-nickel polycrystalline small particles are mixed with high-nickel polycrystalline large particles to achieve high energy density, then energy density is improved, but particle crushing occurs during cold pressing resulting in severe gassing

Engineering Contradiction:

Improveenergy densityVSAvoidgassing performance

Core Design Contradiction:

Quantity of substanceVSReliability

Solution Approach 1:

The patent changes the crystalline structure parameter from polycrystalline to monocrystalline or monocrystalline-like for the small particles, which fundamentally alters the mechanical properties and pressure resistance of the material, enabling high compacted density without particle crushing

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite particle system combining monocrystalline/small particles with polycrystalline/large particles, where each component serves a specific function: monocrystalline particles provide pressure resistance and fill gaps, while polycrystalline particles provide capacity, achieving both high energy density and low gassing

Inventive Principle:

Principle #40Composite materials

2Volume of stationary object

If a high-nickel polycrystalline material with relatively wide particle distribution is used to increase powder compacted density, then compacted density is improved, but particle crushing occurs during cold pressing and cycling resulting in gassing

Engineering Contradiction:

Improvepowder compacted densityVSAvoidgassing performance

Core Design Contradiction:

Volume of stationary objectVSReliability

Solution Approach 1:

The patent changes the crystalline structure parameter from polycrystalline to monocrystalline or monocrystalline-like for the small particles, which fundamentally alters the mechanical properties and pressure resistance of the material, enabling high compacted density without particle crushing

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent applies different crystalline structures to different particle size ranges: monocrystalline or monocrystalline-like structure for small particles (Dv50 ≤ 7 μm) and polycrystalline structure for large particles, optimizing each size range for its specific function

Inventive Principle:

Principle #3Local quality

3Quantity of substance

If nickel content is increased in the positive electrode material to improve reversible capacity, then reversible capacity is improved, but powder compacted density decreases

Engineering Contradiction:

Improvereversible capacityVSAvoidpowder compacted density

Core Design Contradiction:

Quantity of substanceVSVolume of stationary object

Solution Approach 1:

The patent segments the particle population into two distinct size groups (small particles Dv50 ≤ 7 μm and large particles Dv50 > 7 μm), allowing different nickel contents and crystalline structures to be optimized for each segment, with small particles providing compacted density and large particles providing capacity

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent creates a composite particle system combining monocrystalline/small particles with polycrystalline/large particles, where each component serves a specific function: monocrystalline particles provide pressure resistance and fill gaps, while polycrystalline particles provide capacity, achieving both high energy density and low gassing

Inventive Principle:

Principle #40Composite materials

Data Source

PatentEP3800710B1Positive electrode material with high compacted density and electrochemical energy storage device

Publication Date: 2023.02.15 CONTEMPORARY AMPEREX TECHNOLOGY CO LTD

Figure 1~2

AI summary

The present invention relates to the field of battery technologies, and in particular, to a high-compacted-density positive electrode material and an electrochemical energy storage apparatus. The positive electrode material includes a lithium-nickel transition metal oxide A and a lithium-nickel transition metal oxide B. The lithium-nickel transition metal oxide A is secondary particles, whose chemical formula is shown in formula I: Lia1(Nib1Coc1Mnd1)x1M1-x1O2-e1Xe1. The lithium-nickel transition metal oxide B is a monocrystalline structure or a monocrystalline-like structure, whose chemical formula is shown in formula II: Lia2(Nib2Coc2Mnd2)x2M'1-x2O2-e2X'e2 (II). The positive electrode material of the present invention includes the large-particle lithium-nickel transition metal oxide A and the small-particle lithium-nickel transition metal oxide B to improve an energy density of the battery. A degree of crystallinity and particle size distribution of the mixed positive electrode material can improve a compacted density of the high-nickel active material, and ensure lower gassing and good cycle performance.