Lithium Composite Transition Metal Oxide Precursor
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current lithium secondary batteries face challenges with cathode active materials such as LiCoO2 due to safety and cost concerns, while alternatives like LiMn2O4 have lower energy density and performance issues related to Mn dissolution and electrolyte side reactions, and synthesizing lithium transition metal oxides with multiple components like Ni and Mn is complex.
Innovation Solution
A transition metal precursor with a composite compound of Ni, Mn, and Ti, represented by Formula Ni a M b Mn 1-(a+b) (OH 1-x), is developed, allowing for a lithium composite transition metal oxide with a spinel structure that exhibits superior high-speed charge characteristics, lifespan, and charge/discharge efficiency by optimizing particle size and shape through controlled precipitation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of moving object
If LiCoO2 is used as cathode active material, then excellent cycle properties are achieved, but safety is low and cost is high
Solution Approach 1:
The patent uses LiMn1.5Ni0.4Co0.1O4 composite material that combines multiple transition metals (Mn, Ni, Co) to achieve both excellent cycle properties and high safety. The composite structure leverages the advantages of each metal: Mn provides stability and safety, Ni enhances capacity, and Co improves cycle life, resolving the contradiction between safety and performance
2Reliability
If LiMn2O4 is used as cathode active material, then cost is reduced and environmental friendliness is improved, but energy density is low
Solution Approach 1:
The patent develops LiMn1.5Ni0.4Co0.1O4 composite material that maintains the cost-effectiveness and environmental friendliness of manganese-based materials while significantly improving energy density through the addition of Ni and Co. This composite approach achieves 147.2 mAh/g initial charge capacity, resolving the energy density limitation of conventional LiMn2O4
3Power
If LiMn2O4 is substituted with Ni to increase potential, then discharge capacity is improved, but Mn dissolution increases and battery performance decreases
Solution Approach 1:
The patent optimizes the compositional parameters by precisely controlling the ratios of Mn, Ni, and Co in LiMn1.5Ni0.4Co0.1O4. By maintaining Mn as the dominant element (1.5 moles) while adding controlled amounts of Ni (0.4 moles) and Co (0.1 moles), the patent achieves high discharge capacity while suppressing Mn dissolution through the stabilizing effect of Co and the optimized stoichiometry
Solution Approach 2:
The composite LiMn1.5Ni0.4Co0.1O4 material combines the high capacity of Ni-substituted spinel with the stabilizing effect of Co, creating a synergistic structure that prevents Mn dissolution while maintaining high discharge capacity and long-term battery performance
4Ease of manufacture
If solid-phase reaction is used to synthesize lithium transition metal active material, then synthesis is simplified, but manufacturing precision is poor
Solution Approach 1:
The patent employs a co-precipitation method as a preliminary step before the final sintering process. This preliminary action creates a uniformly distributed precursor where Ni, Mn, and Co are pre-mixed at the molecular level, ensuring homogeneous composition in the final product while maintaining process simplicity
5Ease of manufacture
If particle size and shape are not controlled in precursor, then manufacturing process is simplified, but tap density is low and particle shape is non-optimal
Solution Approach 1:
The patent controls precipitation parameters (pH, temperature, addition rate) to produce spherical particles with diameter of 3-10 μm and tap density of 2.8-3.2 g/cm³. By optimizing these process parameters, the patent achieves both manufacturing simplicity and superior particle morphology that enhances battery performance
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 lithium composite transition metal oxide prepared using this precursor demonstrates enhanced performance as a cathode active material, with improved high-speed charge characteristics, lifespan, and charge/discharge efficiency, overcoming the limitations of conventional materials.
Implementation Method 1
use of a transition metal precursor prepared using a co-precipitation method
Implementation Method 2
it is not easy to synthesize the lithium transition metal active material through a simple solid-phase reaction
Data Source
AI summary
Disclosed is a precursor for preparing a lithium composite transition metal oxide. More particularly, a transition metal precursor, including a composite transition metal compound represented by Formula 1 bellow, used to prepare a lithium transition metal oxide: €ƒ€ƒ€ƒ€ƒ€ƒ€ƒ€ƒ€ƒNi a M b Mn 1-(a+b) (OH 1-x ) 2 €ƒ€ƒ€ƒ€ƒ€ƒ(1) wherein M is at least one selected form the group consisting of Ti, Co, Al, Cu, Fe, Mg, B, Cr, Zr, Zn and Period II transition metals; and 0.2‰¤a‰¤0.25, 0‰¤b‰¤0.1, and 0<x<0.5. Since an oxidation number of the transition metal precursor according to the present invention is close to an oxidation number of a transition metal of a lithium composite transition metal oxide, when a lithium composite transition metal oxide is prepared using the transition metal precursor, an oxidation process or a reduction process for change of an oxidation number may be simplified and, as such, process efficiency may be high. In addition, a precursor having high tap density by controlling particle sizes and particle distribution may be synthesized, a particle shape such as a globular shape may be optimized, and uniform precipitation is possible. Therefore, a lithium composite transition metal oxide prepared using the precursor may exhibit superior high-speed charge characteristics and lifespan characteristics, and may have high charge and discharge efficiency, as a cathode active material.