Positive Electrode Active Material Precursor and Method of Preparing the Same
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Solution Overview
Problem
Lithium secondary batteries face limitations in achieving excellent capacity, life, and thermal stability due to the poor thermal properties and high cost of existing positive electrode active materials like LiCoO2, and the high-nickel lithium composite transition metal oxides, which compromise long-term lifetime and stability.
Innovation Solution
A positive electrode active material precursor with a novel structure, comprising distinct regions with high molar ratios of nickel, cobalt, and manganese, and optionally other metals, is developed, where each metal is sequentially deposited in different regions of the particle, enhancing control over the reaction and adjusting composition for optimized properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If LiCoO2 is used as positive electrode active material, then high operating voltage and excellent capacity characteristics are achieved, but poor thermal properties and high cost occur
Solution Approach 1:
The patent applies local quality by creating a multi-region particle structure where different metal compositions are distributed in specific zones. The first region (core) contains high Ni content for capacity, the second region (intermediate) contains Co and Mn for stability, and the third region (surface) contains Mn and Co for thermal protection. This spatial distribution of different material properties resolves the contradiction between achieving high capacity and maintaining thermal stability.
2Reliability
If high-nickel lithium composite transition metal oxide is used to increase capacity, then large capacity is achieved, but long-term lifetime and thermal stability are degraded
Solution Approach 1:
The patent segments the particle into three distinct regions with different metal compositions. The core region (first region) contains high Ni content (≥90 mol%) to maximize capacity, while the intermediate (second region) and surface (third region) contain stabilizing metals like Co and Mn. This segmentation allows the high-nickel core to provide capacity while the outer regions protect against degradation, resolving the contradiction between capacity and long-term stability.
3Reliability
If high-nickel lithium composite transition metal oxide is used to increase capacity, then large capacity is achieved, but thermal stability is degraded
Solution Approach 1:
The patent implements local quality by concentrating high Ni content (≥90 mol%) in the first region (core) while distributing stabilizing metals like Mn and Co in the second and third regions (intermediate and surface). This creates a gradient structure where the thermal stability function is localized to the outer regions that directly contact the electrolyte, while the inner core provides capacity. This resolves the contradiction between high capacity and thermal stability.
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
This approach results in a positive electrode active material with improved high capacity characteristics, life characteristics, and thermal stability, allowing for better lithium ion mobility and enhanced performance in lithium secondary batteries.
Implementation Method 1
forming a first reaction solution containing hydroxide or oxyhydroxide particles of an M1 metal by mixing the first metal solution, an ammonium cationic complexing agent, and a basic compound, and forming the hydroxide or oxyhydroxide particles of the M1 metal through a precipitation reaction
Data Source
AI summary
A positive electrode active material precursor and method of preparing the same are disclosed herein. In some embodiments, a positive electrode active material precursor includes a particle having a first region, a second region, and a third region, a composition of the particle is represented by the following Formula 1 or Formula 2:[M1aM2bM3cM4d](OH)2 [Formula 1][M1aM2bM3cM4d]O·OH [Formula 2]M1, M2, and M3 are different from each other and independently selected from the group consisting of Ni, Co, and Mn, M4 is at least one selected from the group consisting of B, Mg, Ca, Al, Ti, V, Cr, Fe, Zn, Ga, Y, Zr, Nb, Mo, Ta, and W, and 0<a<1, 0<b<1, 0<c<1, 0≤d<1, and a+b+c+d=1, wherein the first region is at a center of a particle, the second region is disposed on the first region, and the third region is disposed on the second region.