Composite Cathode Active Materials for Lithium Battery Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional lithium batteries using LiCoO2 as cathode active materials lack high voltage stability, thermal stability, and high rate discharge characteristics, which are essential for modern mobile devices that require higher electric capacities and stability across varying temperatures.
Innovation Solution
The use of composite cathode active materials comprising large diameter and small diameter active materials in specific particle and weight ratios, along with highly stable and conductive carbon-based materials, to enhance packing density and achieve improved voltage stability, thermal stability, and high rate discharge characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If LiCoO2 powder is used as cathode active material, then high voltage and high capacity can be achieved, but high voltage stability, thermal stability and high rate discharge characteristics are not exhibited
Solution Approach 1:
The patent applies composite materials by combining large diameter LiCoO2 particles with small diameter conductive carbon particles to create a composite cathode active material. This composite structure maintains the high capacity of LiCoO2 while adding the electrical conductivity and stability benefits of carbon, thereby achieving both high electric capacity and high voltage stability simultaneously
2Quantity of substance
If LiCoO2 powder is used as cathode active material, then high voltage and high capacity can be achieved, but thermal stability is not exhibited
Solution Approach 1:
The composite material combines LiCoO2 with conductive carbon particles, where the carbon component provides thermal stability and resistance to thermal degradation. This allows the cathode to maintain high electric capacity while being resistant to harmful thermal effects during battery operation
3Quantity of substance
If LiCoO2 powder is used as cathode active material, then high voltage and high capacity can be achieved, but high rate discharge characteristics are not exhibited
Solution Approach 1:
The composite structure incorporates conductive carbon particles that form a conductive network throughout the cathode material. This network facilitates rapid electron transport during high rate discharge, enabling the battery to maintain high electric capacity while achieving superior high rate discharge characteristics
4Volume of stationary object
If packing density of active material particles is improved, then volume density increases, but high voltage stability, thermal stability and high rate discharge characteristics are limited
Solution Approach 1:
The patent applies local quality by creating a heterogeneous composite where small diameter carbon particles are distributed throughout and around the large diameter LiCoO2 particles. This local distribution ensures that conductive pathways are present throughout the electrode structure, maintaining voltage stability and discharge characteristics while achieving high packing density
Data Source
AI summary
Composite cathode active materials having a large diameter active material and a small diameter active material are provided. The ratio of the average particle diameter of the large diameter active material to the average particle diameter of the small diameter active material ranges from about 6:1 to about 100:1. Mixing the large and small diameter active materials in a proper weight ratio improves packing density Additionally, including highly stable materials and highly conductive materials in the composite cathode active materials improves volume density, discharge capacity and high rate discharge capacity.