Lithium Source Material for Li-Ion Cells
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current lithium-ion battery technology falls short in meeting energy, power, and cost requirements for advanced applications due to limitations in energy density, particularly with silicon-based negative electrodes experiencing high irreversible capacity loss and safety issues with reactive lithiated materials, and existing strategies for providing additional lithium are costly and unsafe.
Innovation Solution
A lithium source material represented by the formula LiyFe1-xMxO4Rz, where M is a transition metal element and R is a halogen, is incorporated into the positive electrode to provide additional lithium, offering high capacity and stability, prepared through a method involving a slurry, drying, grinding, and two-stage firing treatments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If discharged cell materials are used to construct lithium-ion cells, then safety and manufacturing stability are improved, but energy density is limited due to low lithium content in positive electrode active material
Solution Approach 1:
The patent combines discharged positive electrode active material with additional lithium source materials (such as lithium metal powder, lithiated carbon, or other lithium-containing compounds) to create a composite positive electrode. This merging allows the electrode to maintain the stability and safety of discharged materials while incorporating additional lithium sources to increase energy density beyond what the active material alone can provide
Solution Approach 2:
The positive electrode is designed to serve multiple functions: the discharged active material provides structural stability and safety, while the added lithium source materials provide additional lithium inventory for higher capacity. This multi-functional design allows a single electrode to simultaneously achieve safety and high energy density
2Use of energy by moving object
If high capacity negative electrode materials like silicon are used, then energy density is improved, but irreversible capacity loss increases due to volume expansion
Solution Approach 1:
The patent applies pre-lithiation by incorporating lithium source materials into the positive electrode before cell assembly. This preliminary addition of lithium compensates for the irreversible capacity loss that will occur when silicon-based negative electrodes undergo volume expansion during cycling, ensuring that sufficient lithium is available throughout the battery's operational life
Solution Approach 2:
The patent changes the lithium content parameter in the positive electrode by adding lithium source materials beyond what is stoichiometrically required. This parameter change ensures that even after silicon anode expansion causes lithium loss, the cell maintains adequate lithium inventory to sustain high capacity operation
3Use of energy by moving object
If strategies like pre-lithiation or sacrificial lithium electrodes are used to provide additional lithium, then energy density is improved, but manufacturing cost and safety are compromised
Solution Approach 1:
Instead of adding lithium to the negative electrode or using sacrificial lithium electrodes (conventional approaches), the patent inverts the approach by incorporating lithium source materials directly into the positive electrode. This reversal allows lithium to be added in a stable, discharged state that can be safely handled during manufacturing, avoiding the safety and cost issues associated with handling reactive lithiated materials
Solution Approach 2:
The patent uses inexpensive lithium source materials such as lithium metal powder, lithiated carbon, or other cost-effective lithium-containing compounds that can be readily incorporated into the positive electrode. These materials provide additional lithium at low cost compared to conventional approaches requiring specialized handling facilities and procedures
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 lithium source material enhances the energy density of lithium-ion batteries by providing additional lithium without compromising stability, reducing manufacturing costs, and improving safety, while maintaining high capacity and low impedance.
Implementation Method 1
Battery systems that provide electrochemical energy conversion and storage are a practical solution to multiple energy generation applications
Implementation Method 2
subjecting the ground mixture to have a first firing treatment, and then subjecting the obtained product from the first firing treatment to have a second firing treatment; wherein a temperature of the first firing treatment is 400-650° C.; a temperature of the second firing treatment is 700-1000° C.
Data Source
AI summary
The present invention relates to Li-ion cells area, particularly relates to lithium source material and preparation method thereof and use in Li-ion cells. Wherein the lithium source material which is represented by a formula LiyFe1-xMxO4Rz, wherein M represents one or more of transition metal elements, R represents halogen element, 0≤x≤0.9, 0<z≤0.2, 3.5<y≤[5(1−x)+6x]. The lithium source material of the present invention which is lithium deficient relative to its stoichiometric lithium formulation, is a lithium source additive material to the cathode material for Li-ion cells, and exhibits high capacity and high stability.