Composite Cathode Material Balancing Energy Density and Battery Life
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing rechargeable lithium batteries face challenges in achieving high energy density, high average voltage, and excellent lifetime characteristics while maintaining economic feasibility.
Innovation Solution
A positive electrode active material comprising a combination of first particles with an olivine structure, second particles with a spinel structure, and third particles with a layered structure, along with a conductive material and binder, to enhance energy density and voltage stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If a single-type positive electrode active material is used, then the manufacturing process is simple, but the energy density and lifetime characteristics cannot be optimized simultaneously
Solution Approach 1:
The patent applies composite materials by combining three distinct positive electrode active materials with different crystal structures (olivine, spinel, and layered) into a single electrode formulation. Each material type contributes different electrochemical properties, and their synergistic combination achieves high energy density while maintaining structural stability and long cycle life, resolving the contradiction between performance optimization and material complexity.
Solution Approach 2:
The patent segments the positive electrode active material into three distinct particle types with different crystal structures and functional characteristics. By dividing the electrode material into olivine-type particles (for structural stability), spinel-type particles (for conductivity), and layered-type particles (for capacity), the patent optimizes overall electrode performance while managing complexity through defined functional segmentation.
2Quantity of substance
If high-capacity materials are used to increase energy density, then the battery capacity increases, but the lifetime characteristics deteriorate
Solution Approach 1:
The patent applies local quality by assigning different material types to different functional roles within the electrode. The olivine-type material provides structural stability for long-term reliability, while the spinel and layered materials contribute high capacity. This localized functional assignment allows high-capacity materials to be used without compromising lifetime characteristics, as each material type operates in its optimal performance regime.
Solution Approach 2:
The patent uses composite materials to combine high-capacity layered structure materials with structurally stable olivine and spinel materials. This composite approach allows the electrode to achieve high battery capacity from the layered material while the olivine and spinel components maintain structural integrity over repeated cycling, thereby preserving lifetime characteristics despite using high-capacity materials.
3Ease of manufacture
If cobalt-free materials are used to reduce cost, then economic feasibility improves, but the average voltage and energy density decrease
Solution Approach 1:
The patent applies parameter changes by optimizing the compositional ratios and crystal structure parameters of cobalt-free materials. By adjusting the molecular formula parameters (x, y, z in Li1+xLayM1-yO3) and controlling particle morphology, the patent achieves high energy density and average voltage in cobalt-free olivine, spinel, and layered materials, thereby maintaining economic feasibility without sacrificing performance.
Solution Approach 2:
The patent uses composite materials to compensate for the lower intrinsic energy density of individual cobalt-free materials. By combining olivine-type, spinel-type, and layered-type cobalt-free materials in optimized proportions, the electrode achieves high overall energy density and average voltage, making cobalt-free electrodes economically viable while maintaining competitive 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 proposed electrode material achieves high energy density, high average voltage, and improved lifetime characteristics, while being economically viable, through optimized particle structures and compositions.
Implementation Method 1
A rechargeable lithium battery produces electrical energy through the oxidation and reduction reactions when lithium ions are intercalated into and deintercalated from the positive electrode and negative electrode
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A positive electrode active material comprising first particles comprising a compound having an olivine structure, second particles having a spinel structure, and third particles having a layered structure, where the amount of the third particles is about 10 parts by weight to about 50 parts by weight based on 100 parts by weight of the positive electrode active material is disclosed, along with positive electrodes including the positive electrode active materials and a rechargeable lithium battery including the positive electrodes.