Core-Shell Cathode Active Material for Stable High-Nickel Batteries
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Solution Overview
Problem
Nickel-based cathode active materials in lithium batteries suffer from degraded lifespan and poor thermal stability due to side reactions, necessitating a solution to prevent performance deterioration.
Innovation Solution
A composite cathode active material is developed, comprising a 1st core and a 2nd core of lithium transition metal oxides with different average particle diameters, coated with a shell of a first metal oxide and a carbon-based material, such as graphene, to enhance ion and electronic conductivity and prevent side reactions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If nickel-based cathode active materials are used to achieve high capacity, then energy density is improved, but lifespan characteristics and thermal stability deteriorate due to side reactions
Solution Approach 1:
The patent employs a composite cathode active material consisting of a core-shell structure where the core contains nickel-based lithium transition metal oxide for high capacity, and the shell contains aluminum oxide and carbon-based materials that prevent side reactions. This composite structure allows the battery to achieve high energy density while maintaining long lifespan and thermal stability, as the shell protects the nickel-based core from degradation.
2Use of energy by moving object
If nickel-based cathode active materials are used to achieve high capacity, then energy density is improved, but thermal stability deteriorates due to side reactions
Solution Approach 1:
The composite structure combines nickel-based cathode active material with aluminum oxide and carbon-based materials in a core-shell configuration. The shell layer provides thermal stability and prevents side reactions that would otherwise occur at elevated temperatures, allowing the battery to maintain high energy density while achieving improved thermal stability.
3Reliability
If a shell coating is applied to prevent side reactions, then reliability is improved, but device complexity increases
Solution Approach 1:
The patent creates a core-shell composite structure where the shell is formed by coating the nickel-based core with aluminum oxide and carbon-based materials. This composite approach provides effective protection against side reactions while maintaining a relatively simple manufacturing process involving mechanical milling and heat treatment, thus improving reliability without excessive complexity.
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 composite cathode active material improves high-temperature cycle characteristics and suppresses the increase in internal resistance of lithium batteries, leading to enhanced energy density and prolonged battery lifespan.
Implementation Method 1
a shell disposed along a surface of at least one of the 1st core and the 2nd core, wherein the shell includes: at least one first metal oxide represented by MaOb... the at least one first metal oxide is disposed in a matrix of the carbon-based material
Implementation Method 2
a 1st core comprising a lithium transition metal oxide; a 2nd core comprising a second lithium transition metal oxide
Data Source
AI summary
A composite cathode active material, a cathode and a lithium battery that include the composite cathode active material, and a method of preparing the composite cathode active material. The composite cathode active material includes: a 1st core including a first lithium transition metal oxide; a 2nd core including a second lithium transition metal oxide; and a shell disposed along a surface of at least one of the 1st core and the 2nd core, wherein the shell includes: at least one first metal oxide represented by Formula MaOb (where 0<a≤3, 0<b<4, and when a is 1, 2, or 3, b is not an integer); and a carbon-based material, the at least one first metal oxide is disposed in a matrix of the carbon-based material, M is at least one metal selected from Groups 2 to 13, 15, and 16 of the Periodic Table of Elements, and the first lithium transition metal oxide and the second lithium transition metal oxide have a different average particle diameter from each other.