Zirconium-Modified Li-Ion Cathode Material for Excess Lithium Control
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Solution Overview
Problem
The positive electrode slurry in lithium ion secondary batteries often undergoes gelation due to excessive lithium, which reduces operability and yield, particularly when lithium nickel manganese complex oxide particles are used.
Innovation Solution
Incorporating zirconium into lithium nickel manganese complex oxide particles, where zirconium is dispersed within the primary particles and forms a lithium zirconium compound on the surface, helps reduce excessive lithium and residual carbon, inhibiting gelation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If lithium nickel manganese complex oxide particles are used as positive electrode active material, then high energy density and output characteristics are achieved, but gelation occurs in the positive electrode slurry due to excessive lithium
Solution Approach 1:
Zirconium acts as an intermediary substance that reacts with excessive lithium in the lithium nickel manganese complex oxide particles to form lithium zirconium compound. This intermediary reaction prevents the excessive lithium from causing gelation in the slurry, thereby maintaining slurry operability while preserving the high energy density characteristics of the lithium nickel manganese complex oxide material.
2Power
If lithium nickel manganese complex oxide particles are used as positive electrode active material, then high output characteristics are achieved, but gelation occurs in the positive electrode slurry
Solution Approach 1:
Zirconium serves as a mediator that selectively reacts with excessive lithium on the surface of lithium nickel manganese complex oxide particles, forming lithium zirconium compound. This intermediary action removes the harmful excessive lithium that causes gelation, thereby maintaining both high output characteristics and proper slurry operability.
3Ease of operation
If zirconium is incorporated into lithium nickel manganese complex oxide particles to reduce excessive lithium, then gelation is prevented, but manufacturing complexity increases
Solution Approach 1:
The zirconium incorporation step is merged with the existing sintering process. Zirconium is added to the lithium nickel manganese complex oxide mixture before sintering, and the lithium zirconium compound forms in-situ during the normal sintering process. This merging approach prevents gelation without requiring separate additional manufacturing steps, thereby avoiding increased manufacturing complexity.
4Ease of operation
If zirconium is added to form lithium zirconium compound on particle surface, then excessive lithium is reduced and gelation is inhibited, but manufacturing cost increases
Solution Approach 1:
The amount of zirconium added is precisely controlled to achieve the optimal balance between preventing gelation and minimizing material cost. By optimizing the zirconium content parameter, the invention achieves sufficient gelation prevention with minimal zirconium addition, thereby controlling manufacturing costs while maintaining slurry operability.
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 use of zirconium in lithium nickel manganese complex oxide particles effectively prevents gelation of the positive electrode slurry, maintaining high output characteristics and energy density while improving thermal stability and battery capacity.
Implementation Method 1
Incorporating zirconium into lithium nickel manganese complex oxide particles, where zirconium is dispersed within the primary particles and forms a lithium zirconium compound on the surface
Data Source
AI summary
A positive electrode active material for a lithium ion secondary battery containing lithium nickel manganese complex oxide particles, wherein the lithium nickel manganese complex oxide particles are composed of secondary particles in which primary particles of a lithium nickel manganese complex oxide represented by a general formula LidNi1−a−b−cMnaMbZrcO2+α (where M is at least one element selected from Co, W, Mo, Mg, Ca, Al, Ti, Cr, and Ta, and is 0.05≤a<0.60, 0≤b<0.60, 0.00003≤c≤0.03, 0.05≤a+b+c≤0.60, 0.95≤d≤1.20, and −0.2≤α≤0.2), wherein at least a portion of zirconium is dispersed in the primary particle, and wherein an amount of a positive active material for a lithium ion secondary battery in which an amount of excessive lithium determined by a neutralization titration method is 0.02 mass % or more and 0.09 mass % or less.