Lithium Mixed Metal Oxide Cathode for High Density Batteries
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Solution Overview
Problem
Lithium ion batteries face challenges with the limited availability of cobalt for cathode materials and the insufficient thermal stability and cycle stability of LiNiO2, which affects the market's ability to meet demand for high-energy density batteries.
Innovation Solution
Development of pulverulent lithium mixed metal oxides with specific compositions and processes that enhance compressive strength, porosity, and particle shape to maintain electrode homogeneity and achieve high electrode density, including the formula LiaNibM1cM2d(O)2(SO4)x, where M1 and M2 are selected elements, and a preparation process involving co-precipitation, calcination, and deagglomeration to produce particles with high compressive strength and low porosity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If LiNiO2 is used as active cathode material, then electrochemical capacity is improved and cost is reduced, but thermal stability and cycle stability deteriorate
Solution Approach 1:
The patent applies local quality by introducing dopant elements (M1 and M2) at specific positions in the crystal structure of LiNiO2. The dopants are incorporated into the cathode material lattice at controlled concentrations (0.01 ≤ x ≤ 0.05 for sulfate groups, and specific ratios for M1/M2 elements) to locally modify the structural and electronic properties. This localized modification enhances thermal stability and cycle life while preserving the high capacity characteristics of LiNiO2, resolving the contradiction between capacity and reliability.
Solution Approach 2:
The patent creates composite materials by combining LiNiO2 with dopant elements (M1 and M2) and sulfate groups to form a mixed-metal oxide composite structure. The composite cathode material has the formula LiNi1-x-yM1xM2y(O)2(SO4)z, where the combination of multiple elements synergistically improves both thermal stability and electrochemical performance. This composite approach allows simultaneous achievement of high capacity and high reliability.
2Quantity of substance
If electrode density is increased to improve volumetric energy density, then energy density is improved, but manufacturing complexity increases
Solution Approach 1:
The patent applies parameter changes by optimizing the particle morphology parameters of the cathode material, specifically controlling particle size (5-20 μm), particle shape (spherical with smooth surface), and density (3.0-3.5 g/cm³). These parameter optimizations enable high electrode density (≥75% theoretical density) while maintaining manufacturability through conventional electrode fabrication processes. The controlled particle characteristics reduce manufacturing complexity compared to achieving high density through complex processing.
Solution Approach 2:
The patent utilizes spheroidality by producing spherical cathode particles with smooth surfaces and narrow size distribution. The spherical morphology enables efficient packing in electrodes, achieving high volumetric energy density without requiring complex electrode manufacturing processes. The uniform spherical shapes facilitate straightforward slurry preparation, coating, and pressing operations, reducing manufacturing complexity while maximizing energy density.
3Reliability
If cobalt availability is limited, then material availability deteriorates, but electrochemical performance is maintained
Solution Approach 1:
The patent applies the taking out principle by extracting cobalt from the traditional LiCoO2 cathode material and replacing it with nickel-rich LiNiO2 as the base material. Cobalt is completely removed or significantly reduced in the cathode composition, eliminating dependence on cobalt availability. The electrochemical performance previously provided by cobalt is maintained through the nickel-based structure combined with optimized dopants and sulfate groups, achieving both cobalt independence and sustained performance.
Solution Approach 2:
The patent applies this principle by substituting expensive, scarce cobalt with cheaper, abundant nickel as the primary cathode material. Nickel is significantly more economical and available in much larger amounts than cobalt. The use of nickel-rich LiNiO2 with controlled dopants provides a cost-effective, sustainable alternative that maintains electrochemical performance while eliminating supply chain constraints associated with cobalt.
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 resulting lithium mixed metal oxides exhibit high compressive strength, low porosity, and maintained particle shape, enabling high electrode density and improved electrochemical performance, including sustained capacity and cycle stability in lithium ion batteries.
Implementation Method 1
the secondary particles of which have a compressive strength of at least 100 MPa
Implementation Method 2
low porosity, and maintained particle shape, enabling high electrode density
Implementation Method 3
a preparation process involving co-precipitation, calcination, and deagglomeration
Implementation Method 4
a preparation process involving co-precipitation, calcination, and deagglomeration
Implementation Method 5
a preparation process involving co-precipitation, calcination, and deagglomeration
Data Source
AI summary
The present invention relates to pulverulent compounds of the formula LiaNibM1cM2d(O)2(SO4)x, a process for preparation thereof and the use thereof as active electrode material in.