Dual-Particle Cathode Composition for Low-Temperature High-Voltage Cells
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Solution Overview
Problem
Existing rechargeable lithium batteries face challenges in achieving high energy density, high operating voltage, and low-temperature performance.
Innovation Solution
A positive electrode active material comprising first particles with a compound of Chemical Formula 1 and second particles with a compound of Chemical Formula 2, where the first particles are in a single particle form and have a higher content, and the second particles are in a single particle form, enhancing conductivity and stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If a single positive electrode active material is used, then the battery structure is simple, but the energy density and operating voltage are limited
Solution Approach 1:
The patent employs a composite positive electrode active material consisting of two distinct compounds: LiFe0.4Mn0.5Ti0.1PO4 (first particles) and Li1.3Ni0.3Mn0.4Co0.05Al0.05O2 (second particles). This composite structure combines the advantages of both materials - the olivine structure provides stability and safety while the layered structure contributes high voltage and capacity, thereby achieving high energy density without excessive structural complexity
Solution Approach 2:
The patent applies local quality by assigning different functional roles to different particle types within the composite. The first particles (LiFe0.4Mn0.5Ti0.1PO4) primarily provide structural stability and safety, while the second particles (Li1.3Ni0.3Mn0.4Co0.05Al0.05O2) contribute high operating voltage and capacity. This functional differentiation allows each component to optimize its local performance characteristics
2Power
If high voltage materials are used to increase operating voltage, then the energy density improves, but the low-temperature performance deteriorates
Solution Approach 1:
The patent modifies the chemical composition parameters of the positive electrode active material by incorporating specific ratios of transition metals (Fe, Mn, Ti, Ni, Co, Al) and adjusting the stoichiometry of both compounds. The presence of Ti in the olivine structure and Al in the layered structure specifically enhances ionic conductivity at low temperatures, while maintaining high operating voltage through the synergistic combination of both materials
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 solution results in a rechargeable lithium battery with improved energy density, operating voltage, and low-temperature properties, ensuring efficient lithium ion intercalation and deintercalation.
Implementation Method 1
The battery produces electrical energy through the oxidation and reduction reactions if (e.g., when) lithium ions are intercalated into and deintercalated from the positive electrode and the negative electrode
Data Source
AI summary
A positive electrode active material for a rechargeable lithium battery, a positive electrode including the positive electrode active material, and a rechargeable lithium battery including the positive electrode are disclosed. For example, the positive electrode active material may include first particles including a compound of Chemical Formula 1 and second particles including a compound of Chemical Formula 2. The content (e.g., amount) of the first particles may be greater than the content (e.g., amount) of the second particles, and the second particles may have (e.g., be in) a single particle form.