Pre-Lithiated Cathode Material with Spinel Phase for First-Cycle Capacity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Lithium ion batteries suffer from irreversible capacity loss during the first charge-discharge process due to lithium extraction from the positive electrode material exceeding insertion into the negative electrode, leading to reduced energy density and safety concerns, with existing methods to enhance energy density often compromising safety performance.
Innovation Solution
A pre-lithiated lithium ion positive electrode material with a chemical formula of Li2O/[A(3-x)Me x ]1/3-LiAO2, where A includes Ni, Co, and Mn, and Me includes Al, Mg, Ti, Zr, Y, Mo, W, Na, Ce, Cr, Zn, or Fe, is prepared by a method involving a sulfate solution, precipitant, and complexing agent, followed by calcination and pre-lithiation with a naphthalene-containing conjugate, forming a spinel phase structure that enhances lithium diffusion and stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If additional lithium is added to the negative electrode to increase discharge capacity, then the energy density is improved, but the battery compatibility and safety performance are reduced
Solution Approach 1:
The patent applies inversion by reversing the conventional pre-lithiation approach. Instead of adding lithium to the negative electrode, the patent adds Li2O coating to the positive electrode material. This inverted approach achieves the same goal of compensating for lithium loss while maintaining better safety and compatibility, as the Li2O is contained within the positive electrode structure rather than adding reactive lithium metal to the negative electrode.
Solution Approach 2:
The Li2O coating acts as an intermediary between the lithium cobalt oxide core and the electrolyte. It provides a controlled source of additional lithium that can be released during charging, mediating the lithium balance without requiring direct addition of reactive lithium metal to the negative electrode, thus maintaining safety while improving capacity.
2Productivity
If a spinel phase structure is formed on the positive electrode material surface, then lithium diffusion and electrochemical activity are enhanced, but the manufacturing complexity increases
Solution Approach 1:
The patent applies composite materials by creating a Li2O/Co composite structure on the surface of lithium cobalt oxide particles. This composite coating combines Li2O (providing additional lithium source) and Co (forming spinel phase LiCoO3 during calcination that enhances lithium diffusion). The composite structure achieves improved lithium diffusion and electrochemical activity while maintaining a relatively simple manufacturing process through co-precipitation and calcination.
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 pre-lithiated material achieves a higher first discharge capacity, improved high-voltage resistance, and extended cycle life, with the spinel phase structure providing three-dimensional lithium channels and enhanced electrochemical activity, while maintaining compatibility with existing battery manufacturing processes.
Implementation Method 1
pre-lithiation with a naphthalene-containing conjugate, forming a spinel phase structure
Implementation Method 2
the spinel phase structure providing three-dimensional lithium channels and enhanced electrochemical activity
Implementation Method 3
preparation method involving a sulfate solution, precipitant, and complexing agent
Implementation Method 4
followed by calcination and pre-lithiation with a naphthalene-containing conjugate
Data Source
Figure 1~2
Figure 3~4
AI summary
Disclosed are a pre-lithiated lithium ion positive electrode material, a preparation method therefor and use thereof. The lithium ion positive electrode material has a chemical formula of Li2O/[A(3-x)Mex]1/3-LiAO2, wherein A comprises M, and wherein M is at least one of Ni, Co, and Mn; and wherein Me is at least one of Ni, Mn, Al, Mg, Ti, Zr, Y, Mo, W, Na, Ce, Cr, Zn or Fe; and wherein 0 < x < 0.1. The material is co-doped with multiple elements, and these elements act synergistically to inhibit the irreversible phase change at a high voltage and improve the stability of the structure of a substrate. The spinel phase A(3-x)MexO4 structure contains the doping elements, which work together to improve the interfacial activity of the material and introduce more electrochemically active sites.