Dual-Particle Cathode Material for Voltage and Cold-Start Performance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing rechargeable lithium batteries face challenges in achieving high energy density, high operating voltage, and desirable low-temperature properties.
Innovation Solution
A positive electrode active material comprising first particles of Li a1 Mn x1 Fe y1 B z1 PO 4-b1 and second particles of Li a2 Ni x2 Co y2 Mn z2 O 2-b2, with specific compositional ranges and particle sizes, combined with a conductive material and binder, to enhance conductivity and stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If high capacity materials are used to increase energy density, then energy density is improved, but operating voltage and conductivity deteriorate
Solution Approach 1:
The patent uses a composite material system consisting of Li-rich layered oxide particles (providing high capacity) coated with a spinel coating layer containing Mn, Ni, and Co (providing high voltage and conductivity). This composite structure allows the interior Li-rich particles to contribute high capacity while the exterior spinel coating maintains high operating voltage and electrical conductivity, resolving the contradiction between energy density and power.
2Quantity of substance
If high capacity materials are used to increase energy density, then energy density is improved, but electrical conductivity deteriorates
Solution Approach 1:
The spinel coating layer containing Mn, Ni, and Co serves as a conductive shell around the Li-rich layered oxide particles. The spinel structure inherently provides good electrical conductivity, which compensates for the low conductivity of the Li-rich particles, thereby maintaining high electrical conductivity while achieving high energy density.
Solution Approach 2:
The coating layer is applied locally on the surface of the Li-rich particles, creating a heterogeneous structure where the core provides high capacity and the shell provides high conductivity. This local differentiation allows each region to optimize its function without compromising the other.
3Ease of manufacture
If conventional positive electrode materials are used, then manufacturing is simple, but low-temperature performance deteriorates
Solution Approach 1:
The composite structure of Li-rich layered oxide with spinel coating provides inherent low-temperature performance benefits. The spinel coating layer facilitates ion and electron transport at low temperatures, improving battery performance in cold environments while maintaining compatibility with conventional manufacturing processes.
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 performance, while maintaining structural integrity and longevity.
Implementation Method 1
produces electrical energy through the oxidation and reduction reactions if lithium ions are intercalated into and deintercalated from the positive electrode and negative electrode
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Disclosed are positive electrode active materials for a rechargeable battery, positive electrodes including the same, and rechargeable lithium batteries including the same. For example, the positive electrode active material includes first particles including a compound of Chemical Formula 1 and having a first average particle diameter, and second particles including a compound of Chemical Formula 2 and having a second average particle diameter that is greater than the first average particle diameter. The content of the first particles is greater than or equal to the content of the second particles.