Core-Shell Cobalt-Coated Nickel Cathode for Lithium Battery
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Nickel-based lithium transition metal oxide cathodes in lithium batteries face challenges with low discharge capacity per unit volume, inadequate stability, and poor high-rate characteristics due to low packing density and thermal instability.
Innovation Solution
A composite cathode active material is developed with a nickel-based lithium transition metal oxide core coated with a single layer of cobalt, which improves thermal and structural stability, and charge-discharge efficiency by forming a core-shell structure with a cobalt-rich coating layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If nickel-based lithium transition metal oxide is used as cathode active material, then high discharge capacity per unit weight is achieved, but low packing density results in low discharge capacity per unit volume
Solution Approach 1:
The patent applies composite materials by creating a core-shell structure where nickel-based lithium transition metal oxide core is coated with cobalt-containing material. This composite structure increases the packing density of the cathode active material particles, thereby improving discharge capacity per unit volume while maintaining the high discharge capacity per unit weight provided by the nickel-based core material.
2Quantity of substance
If nickel-based lithium transition metal oxide is used, then high discharge capacity per unit weight is achieved, but inadequate stability is observed
Solution Approach 1:
The patent uses composite materials by forming a coating layer of cobalt-containing material on the nickel-based lithium transition metal oxide core. This composite structure provides thermal and chemical stability to the nickel-based core, preventing degradation and improving reliability while preserving the high discharge capacity per unit weight.
Solution Approach 2:
The patent applies a thin film coating of cobalt-containing material on the cathode active material particles. This thin film shell protects the nickel-based core from thermal and chemical degradation, improving stability and reliability while maintaining the electrochemical performance.
3Quantity of substance
If nickel-based lithium transition metal oxide is used, then high discharge capacity per unit weight is achieved, but poor high-rate characteristics and low charge-discharge efficiency result
Solution Approach 1:
The patent applies composite materials by coating nickel-based lithium transition metal oxide with cobalt-containing material. The cobalt-rich coating layer has superior ionic and electronic conductivity, which enhances the charge-discharge efficiency and high-rate characteristics of the cathode while maintaining the high discharge capacity per unit weight of the nickel-based core.
4Quantity of substance
If nickel-based lithium transition metal oxide is used, then high discharge capacity per unit weight is achieved, but low thermal stability is observed
Solution Approach 1:
The patent uses composite materials by creating a core-shell structure where the nickel-based lithium transition metal oxide core is coated with thermally stable cobalt-containing material. This composite structure provides thermal stability to the nickel-based core, preventing thermal runaway and degradation at elevated temperatures while preserving the high discharge capacity per unit weight.
Solution Approach 2:
The patent applies a thin film coating of cobalt-containing material on the cathode active material particles. This thin film shell acts as a thermal barrier, protecting the nickel-based core from thermal degradation and improving thermal stability while maintaining the electrochemical 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 composite cathode active material enhances the lithium battery's discharge capacity per unit volume, stability, and high-rate characteristics, while preventing side reactions and extending the battery's lifetime.
Implementation Method 1
heating the coated core at a temperature ranging from about 600° C. to about 900° C. in an air atmosphere
Data Source
AI summary
In an aspect, a composite cathode active material a cathode and a lithium battery including the composite cathode active material, and a method of preparing the composite cathode active material is disclosed.