Atomized Phosphate-Coated Cathode for Uniform Li-Ion Cycling
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Solution Overview
Problem
Existing lithium ion battery cathode materials face challenges with cracking after long cycles, leading to exposure of internal structures and reduced stability, as well as issues with coating uniformity and residual lithium affecting performance.
Innovation Solution
A composite cathode material with a phosphate compound coating layer is developed, using an atomizing coating process to improve coating uniformity and control the coating amount, enhancing the material's hardness, conductivity, and stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If liquid phase coating method is used, then coating material can be applied to cathode material surface, but coating uniformity is poor and coating amount is difficult to control
Solution Approach 1:
The patent changes the physical state parameter of the coating material from liquid to solid particles. This parameter change enables precise control of coating amount through particle size and concentration control, and achieves uniform coating through solid phase diffusion, resolving the issues of poor coating uniformity and difficult process control inherent in liquid phase methods
Solution Approach 2:
The patent employs phase transition by converting the coating material from dissolved state (liquid phase) to solid precipitate form. The solid coating material is introduced as fine particles that deposit uniformly on the cathode material surface through solid phase reaction, eliminating the coating defects associated with liquid phase methods while maintaining ease of manufacture
2Manufacturing precision
If solid phase coating is used, then coating uniformity improves, but excessive residual lithium remains affecting processing performance
Solution Approach 1:
The patent applies local quality by using solid coating particles with controlled size distribution that selectively deposit on the surface of cathode material particles. The coating process creates a localized phosphate layer on the outer surface while maintaining the bulk properties of the cathode material, achieving both uniform coating and acceptable processing performance by controlling the local composition rather than uniform throughout the entire material
3Use of energy by moving object
If nickel-rich cathode material is used, then energy density increases, but particles crack after long cycle reducing stability
Solution Approach 1:
The patent creates a composite material structure by coating nickel-rich cathode material particles with phosphate compounds. This composite structure combines the high energy density characteristics of nickel-rich materials with the structural stability and protective properties of phosphate compounds, resolving the contradiction between achieving high energy density and maintaining cycling stability by combining two materials with complementary properties
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 composite cathode material achieves improved rate performance, cycling stability, and thermal stability, while reducing production costs and avoiding filtration losses associated with conventional liquid phase coating methods.
Implementation Method 1
a coating layer distributed on a surface of the active material, where the coating layer includes a phosphate compound
Implementation Method 2
using an atomizing coating process to improve coating uniformity and control the coating amount
Data Source
AI summary
The present application relates to field of cathode material, and a cathode material and a method for preparing the same, a lithium ion battery provided, where the cathode material includes an active material having a chemical formula Lia(NixCoyRz)1-bMbO2, where 0.9≤a≤1.10, x+y+z=1, 0.8≤x≤0.99, 0≤y≤0.15, 0≤z≤0.1, 0≤b≤0.1; R includes Al and/or Mn, M includes a metal element; and a coating layer on surface of the active material, where the coating layer includes a phosphate compound; the cathode material has a particle hardness of Cs≥50 Mpa and satisfies the following: Cs10/Cs50≥0.7; where Cs10 is hardness of particles with a particle size D10, and Cs50 is hardness of particles with a particle size D50. The cathode material and method for preparing the same, lithium ion battery provided, which improve coating uniformity, precisely control coating amount, improve rate and cycling performance of lithium ion battery, and reduce production costs.