Positive Electrode Material Combining Olivine, Spinel, and Layered Phases
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Solution Overview
Problem
Existing rechargeable lithium batteries face challenges in achieving high energy density and extended lifetime 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, enhances the performance of rechargeable lithium batteries.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a single positive electrode active material is used, then the battery structure is simple, but the energy density and lifetime characteristics cannot be simultaneously optimized
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 contributes different properties: the olivine structure provides structural stability and long cycle life, the spinel structure enhances ionic conductivity and rate performance, and the layered structure increases capacity. This composite approach resolves the contradiction by achieving optimized lifetime characteristics through synergistic material combinations while maintaining a manageable electrode structure.
2Use of energy by moving object
If high capacity materials are used to increase energy density, then the energy density improves, but the structural stability and lifetime deteriorate
Solution Approach 1:
The patent applies local quality by assigning different functional roles to different materials within the composite electrode. The layered structure material (e.g., LiCoO2 or LiNi0.8Co0.1Mn0.1O2) provides high capacity and energy density in specific regions, while the olivine structure material (e.g., LiFePO4) provides structural stability and the spinel structure material (e.g., LiMn2O4) provides ionic conductivity. This spatial and functional differentiation allows the electrode to achieve high energy density without sacrificing structural stability, as each material performs its specialized function locally within the composite system.
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 and improved lifetime characteristics, offering enhanced charge and discharge efficiency, structural stability, and cost-effectiveness.
Implementation Method 1
Electrical energy is generated (produced) through the oxidation and reduction reactions when lithium ions are intercalated into and deintercalated from the positive and negative electrodes
Data Source
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AI summary
A positive electrode active material includes first particles including a compound represented by Chemical Formula 1 having an olivine structure, second particles including a compound represented by Chemical Formula 2 having a spinel structure, and third particles including a compound of Chemical Formula 3 having a layered structure. The first particles and the second particles constitute a main active material of the positive electrode active material, and a content of the main active material is about 95 parts by weight to about 99.5 parts by weight based on about 100 parts by weight of the positive electrode active material. Also disclosed are positive electrodes including the positive electrode active materials, and rechargeable lithium batteries including the same.