Positive Electrode Active Material Coating Against Cation Mixing
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Solution Overview
Problem
Lithium nickel-cobalt-manganese oxide (LNCMO) based positive electrode active materials with high Ni content face issues of cation mixing, leading to battery life deterioration and reduced capacity due to unstable Ni3+ reduction, and coating these materials can further decrease capacity.
Innovation Solution
A positive electrode active material with a specific composition and surface coating, characterized by I003/I104 and (I102+I006)/(I101) values within certain ranges, and a c-axis length of 14.1870 Å to 14.1893 Å, along with a controlled outer layer comprising M2 and M3 components, is manufactured through precise sintering and heat-treating processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If high Ni content LNCMO is used to increase capacity, then battery capacity is improved, but cation mixing occurs leading to reduced battery lifetime
Solution Approach 1:
The patent applies local quality by creating a dual-component outer layer where M2 component (containing at least three elements from Al, Ti, Zr, Mg, Zn, B, Mo, Fe, Co, Ni, Ba, W) and M3 component (different from M2) are distributed on different portions of the particle surface. This localized composition strategy prevents cation mixing at the surface without affecting the high-Ni core material's capacity properties, thus resolving the contradiction between capacity and lifetime.
Solution Approach 2:
The patent uses composite materials by combining the high-Ni LNCMO core with a multi-element outer layer comprising M2 and M3 components. The M2 component contains at least three selected elements while M3 contains at least one different element, creating a composite structure that leverages the high capacity of Ni-rich material while the composite outer layer prevents cation mixing and improves structural stability for extended lifetime.
2Reliability
If coating is applied to prevent cation mixing, then battery lifetime is improved, but battery capacity is reduced
Solution Approach 1:
The patent applies local quality by creating a dual-component outer layer where M2 component (containing at least three elements from Al, Ti, Zr, Mg, Zn, B, Mo, Fe, Co, Ni, Ba, W) and M3 component (different from M2) are distributed on different portions of the particle surface. This localized composition strategy prevents cation mixing at the surface without affecting the high-Ni core material's capacity properties, thus resolving the contradiction between capacity and lifetime.
Solution Approach 2:
The patent applies parameter changes by precisely controlling the outer layer composition parameters: M2 component content at 0.9-1.8 mol%, M3 component content at 0.25-0.35 mol%, and specific element selections from the given groups. These parameter optimizations ensure the coating provides sufficient protection against cation mixing while maintaining high battery capacity through minimal and targeted element addition.
3Stability of the object's composition
If outer layer composition is optimized to prevent cation mixing, then structural stability is improved, but manufacturing complexity increases
Solution Approach 1:
The patent applies parameter changes by precisely controlling the outer layer composition parameters: M2 component content at 0.9-1.8 mol%, M3 component content at 0.25-0.35 mol%, and specific element selections from the given groups. These parameter optimizations ensure the coating provides sufficient protection against cation mixing while maintaining high battery capacity through minimal and targeted element addition.
Solution Approach 2:
The patent applies local quality by creating a dual-component outer layer where M2 component (containing at least three elements from Al, Ti, Zr, Mg, Zn, B, Mo, Fe, Co, Ni, Ba, W) and M3 component (different from M2) are distributed on different portions of the particle surface. This localized composition strategy prevents cation mixing at the surface without affecting the high-Ni core material's capacity properties, thus resolving the contradiction between capacity and lifetime.
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 solution enhances both battery capacity and lifetime by improving cation mixing resistance and maintaining structural stability, resulting in improved initial charging/discharging efficiency and high-temperature lifespan.
Implementation Method 1
sintering a first mixture comprising the transition metal hydroxide, a M1 component precursor, and a lithium compound to obtain a first lithium composite oxide
Implementation Method 2
sintering a second mixture comprising the first lithium composite oxide and a M2 component precursor to obtain a second lithium composite oxide
Implementation Method 3
heat-treating a third mixture comprising the dried second lithium composite oxide and a M3 component precursor
Data Source
AI summary
A positive electrode active material of the present disclosure is capable of improving capacity and lifetime of a battery simultaneously, a battery of the present disclosure can have improved capacity and lifetime simultaneously, a method of the present disclosure is able to manufacture a positive electrode active material capable of improving capacity and lifetime of a battery simultaneously.