Composite Cathode Material Balancing Lithium Battery Capacity and Life
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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 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 by optimizing energy density and lifetime characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single positive electrode active material is used, then the battery structure is simple and manufacturing is easy, 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 structures) into a single electrode formulation. This composite approach allows the electrode to simultaneously achieve high energy density from the layered structure material and extended lifetime from the olivine and spinel structure materials, resolving the contradiction between structural simplicity and performance optimization.
Solution Approach 2:
The patent segments the positive electrode active material into three distinct particle types with different crystal structures and functional characteristics. Each particle type contributes specific properties: olivine structure for stability, spinel structure for conductivity, and layered structure for capacity. This segmentation enables independent optimization of each component's properties while achieving synergistic overall performance.
2Quantity of substance
If high-capacity materials are used to increase energy density, then the battery capacity increases, but the structural stability and lifetime deteriorate
Solution Approach 1:
The patent uses composite materials combining three different crystal structures where the layered structure material (Li2NiO2 or Li2CoO2) provides high lithium ion capacity, while the olivine structure material (LiFePO4 or LiMnPO4) and spinel structure material (LiMn2O4 or LiNi0.8Co0.1Mn0.1O2) provide structural stability. This composite formulation resolves the contradiction by distributing functional responsibilities across different material phases.
Solution Approach 2:
The patent applies local quality by assigning different functional roles to different material phases within the same electrode. The layered structure material locally provides high capacity in specific regions, while the olivine and spinel structure materials locally provide structural stability in other regions, allowing the overall electrode to achieve both high capacity and stability simultaneously.
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 configuration improves energy density and extends the battery's lifetime, offering a cost-effective solution for high-performance lithium batteries.
Implementation Method 1
A rechargeable lithium battery is a battery including a positive electrode and a negative electrode, both including active materials capable of intercalation and deintercalation of lithium ions
Implementation Method 2
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
AI summary
Positive electrode active materials for a rechargeable lithium battery, positive electrodes including the same, and rechargeable lithium batteries including the same are provided. A positive electrode active material includes first particles including a compound represented by Chemical Formula 1 and having an olivine structure, second particles including a compound represented by Chemical Formula 2 and having a spinel structure and third particles including a compound of Chemical Formula 3 and 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.