Gradient Spherical Cathode Particles for Li-Ion Batteries
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Lithium ion batteries face issues with inadequate cycling stability, lifetime reliability, and power durability, especially at elevated temperatures, due to inadequate cathode materials, which also lead to gas evolution and rapid failure.
Innovation Solution
Development of spherical particles of transition metal carbonates or hydroxides with specific concentration gradients of nickel, cobalt, manganese, and other metals, which are used to produce lithiated mixed transition metal oxides with improved rate capability and cycling stability without compromising energy density.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If nickel-rich cathode materials are used to increase energy density, then specific capacity is improved, but cycling stability and reliability deteriorate
Solution Approach 1:
The patent applies local quality by creating a radial concentration gradient of transition metal cations within the particle structure. The concentration of at least one transition metal cation varies with radius, having at least one relative extreme value that is neither in the center nor at the edge, creating zones with different chemical compositions and properties within the same particle. This allows different regions to contribute differently to capacity and stability.
Solution Approach 2:
The patent employs composite materials by combining multiple transition metal cations (nickel, cobalt, manganese, titanium, vanadium, chromium, iron) in a single particle structure with non-uniform distribution. This composite approach leverages the beneficial properties of each metal while mitigating their individual drawbacks through spatial separation and gradient composition.
2Quantity of substance
If nickel content is increased to improve energy density, then specific capacity is enhanced, but gas evolution increases leading to rapid failure
Solution Approach 1:
By creating local zones with varying nickel concentration through the radial gradient, the patent reduces gas evolution in regions where high nickel content would otherwise cause excessive gas generation, while maintaining high capacity in other zones. The non-uniform distribution allows optimization of local chemistry to suppress harmful gas evolution.
3Ease of manufacture
If conventional cathode materials are used to maintain simplicity, then manufacturing is easier, but rate capability and power durability are insufficient
Solution Approach 1:
The patent applies parameter changes by modifying the concentration parameter of transition metal cations as a function of radial position. This gradient parameter creates particles with optimized electrochemical properties for rate capability and power durability while maintaining compatibility with existing manufacturing processes for producing spherical particles.
4Ease of manufacture
If uniform composition particles are used to simplify production, then manufacturing is easier, but cycling stability at elevated temperature is inadequate
Solution Approach 1:
The patent implements local quality through radial concentration gradients that create zones with different compositional characteristics optimized for thermal stability. At least one transition metal cation has a concentration profile with relative extreme values at intermediate radial positions, providing local chemical environments that enhance cycling stability at elevated temperatures while maintaining overall production feasibility.
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 these spherical particles as cathode materials enhances the rate capability and cycling stability of lithium ion batteries at high temperatures without reducing energy density, leading to improved battery performance and reliability.
Implementation Method 1
the concentration of at least one of the transition metal cations, plotted against the radius of the particle in question, has at least one relative extreme value which is neither in the center nor at the edge of the particle in question
Implementation Method 2
lithium-containing mixed transition metal oxides are used as the active material
Data Source
AI summary
Spherical particles of transition metal carbonates, transition metal hydroxides or transition metal carbonate hydroxides comprising cations of at least two transition metals selected from nickel, cobalt, manganese, titanium, vanadium, chromium and iron, wherein the concentration of at least one of the transition metal cations, plotted against the radius of the particle in question, has at least one relative extreme value which is neither in the center nor at the edge of the particle in question.