Cathode Composite Oxide Composition for High-Output Li-Ion Batteries
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Solution Overview
Problem
Current methods for improving lithium secondary battery output characteristics, such as those described in Patent Literatures 1 and 2, have limitations that need further enhancement to achieve better performance.
Innovation Solution
A lithium-containing transition metal composite oxide is developed, represented by Formula (I) Li[Lix(Ni(1-y-z-w)CoyMnzMw]O2, where specific conditions are met, including X-ray photoelectron spectroscopy ratios, BET specific surface area, crystallite size, and particle size, along with a manufacturing method involving a mixing, calcining, and washing process to optimize the material's properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If conventional methods (Patent Literatures 1 and 2) are used to improve output characteristics, then some battery performance is enhanced, but output characteristics still have room for further improvement
Solution Approach 1:
The invention changes the chemical composition parameters by introducing a specific element M (where M is at least one of Al, Ga, In, B, or Ti) into the lithium nickel composite oxide structure with controlled atomic ratios (0 < w ≤ 0.5 and 0.95 ≤ y + z + w < 1.0). This parameter modification resolves the contradiction by achieving both improved output characteristics and reliable battery performance through optimized compositional parameters.
Solution Approach 2:
The invention creates a composite material system by combining lithium nickel composite oxide with additional transition metal elements (Co, Mn, and element M) in a specific composite structure represented by Formula (I). This composite approach resolves the technical contradiction by synergistically combining multiple elements to achieve both high power output and reliable performance that cannot be achieved by single-element modifications alone.
2Productivity
If lithium insertion and desorption efficiency is increased, then output characteristics improve, but formation of lithium carbonate and hydroxide increases which hinders performance
Solution Approach 1:
The invention converts the harmful effect of lithium carbonate and hydroxide formation into a beneficial outcome by introducing element M that modifies the surface chemistry and reaction pathways. The controlled presence of element M (with atomic ratio 0 < w ≤ 0.5) transforms the harmful side reaction into a controlled process that actually enhances lithium insertion/desorption efficiency while suppressing harmful byproduct accumulation.
Solution Approach 2:
Element M acts as an intermediary substance between lithium ions and the oxide structure, facilitating efficient lithium insertion and desorption while simultaneously preventing direct reactions that form lithium carbonate and hydroxide. The intermediary element M (Al, Ga, In, B, or Ti) mediates the interaction, achieving high productivity without generating harmful factors.
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 provides a lithium secondary battery with enhanced output characteristics, high cycle performance, and improved thermal stability, achieving efficient lithium insertion and desorption, and suppressing the formation of lithium carbonate and hydroxide that hinder battery performance.
Implementation Method 1
when X-ray photoelectron spectroscopy is performed, and a ratio between α and β is referred to as γ (α/β=γ), γ is calculated for each of a surface of the secondary particle and an inside of the secondary particle
Implementation Method 2
secondary particles that are aggregate of primary particles into or from which lithium ions are dopable or dedopable
Data Source
AI summary
This lithium-containing transition metal composite oxide includes secondary particles that are aggregates of primary particles into or from which lithium ions are dopable or dedopable, and satisfies the following conditions:(1) the lithium-containing transition metal composite oxide is represented by Formula (I),Li[Lix(Ni(1-y-z-w)CoyMnzMw)1-x]O2 (I)(2) from X-ray photoelectron spectroscopy, a specific γ is calculated for each of the surface of the secondary particle and the inside of the secondary particle, and when the γ value of the surface of the secondary particle is referred to as γ1 and the γ value of the inside of the secondary particle is referred to as γ2, γ1 and γ2 satisfy the condition of Formula (II).0.3≤γ1/γ2≤1.0 (II)