O2-Type Cathode Mixture with Plate and Spherical Particle Balance
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Solution Overview
Problem
Positive electrode active materials with an O2-type structure have limited capacity when used in lithium-ion batteries.
Innovation Solution
A positive electrode mixture comprising a plate-like first active material and a spherical second active material with a specific diameter ratio and mass ratio, along with optional components like a solid electrolyte, conductive aid, and binder, to enhance the capacity of lithium-ion batteries.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If a positive electrode active material with an O2-type structure is used, then the battery can operate with lithium-ion technology, but the capacity is limited and needs improvement
Solution Approach 1:
The patent applies composite materials by combining plate-like O2-type particles with spherical O2-type particles in a specific size ratio (0.1 ≤ D1L/D2 ≤ 1.5). This composite structure allows the plate-like particles to provide high capacity while the spherical particles improve packing density and utilization, resolving the capacity limitation issue through material composition optimization rather than using a single material type.
Solution Approach 2:
The patent applies local quality by creating a heterogeneous particle size distribution within the positive electrode mixture. The plate-like particles (with long diameter D1L) and spherical particles (with diameter D2) have different local structural qualities that complement each other, allowing different regions of the electrode to contribute differently to overall capacity while maintaining structural integrity.
2Quantity of substance
If only plate-like O2-type particles are used, then high capacity can be achieved, but particle utilization and interaction are insufficient
Solution Approach 1:
The patent applies parameter changes by controlling the size ratio parameter (D1L/D2) between plate-like and spherical particles within a specific range (0.1 to 1.5). This parameter optimization ensures that the particles interact effectively during lithium insertion/extraction cycles, improving utilization without sacrificing the high capacity characteristics of the plate-like structure.
Solution Approach 2:
The patent uses composite materials with a mass ratio of plate-like to spherical particles between 10:90 and 90:10. This composite approach enhances particle utilization by combining the high capacity advantage of plate-like particles with the better packing and interaction properties of spherical particles, resolving the productivity issue.
3Quantity of substance
If the particle size ratio is not optimized, then manufacturing is simpler, but battery performance and capacity are reduced
Solution Approach 1:
The patent establishes specific parameter ranges for particle size ratio (0.1 ≤ D1L/D2 ≤ 1.5) and mass ratio (10-90% plate-like particles) to optimize capacity while providing clear manufacturing guidelines. These defined parameters balance performance requirements with manufacturing feasibility, avoiding overly complex control requirements.
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 mixture improves the capacity of lithium-ion batteries by optimizing the utilization and interaction of the active materials, leading to enhanced performance.
Implementation Method 1
a positive electrode active material having an O2-type structure can be obtained by ion exchange of at least a portion of Na in a Na-containing transition metal oxide having a P2-type structure with Li
Data Source
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AI summary
Disclosed is a technique that can improve capacity of a positive electrode active material having an O2-type structure when applied to a positive electrode active material layer of a lithium-ion battery. The positive electrode mixture of the present disclosure comprises a first active material and a second active material, the first active material has an O2-type structure and is plate-like, the second active material has an O2-type structure and is spherical, a ratio D1L/D2 of a long diameter D1L of the first active material to a diameter D2 of the second active material is 0.1 or greater and 1.5 or less, and a ratio of the first active material relative to a total of the first active material and the second active material is 10% by mass or greater and 90% by mass or less.