Pre-Lithiated Electrode Material With Inorganic Lithium Protective Layer
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Solution Overview
Problem
Secondary batteries face challenges in maintaining high energy density and cycling performance due to irreversible loss of active lithium ions during the formation process and capacity degradation from SEI film rupture.
Innovation Solution
An electrode material with a pre-lithiated substrate and a first inorganic lithium compound layer, comprising lithium oxide, nitride, carbonate, fluoride, or sulfide, forms a stable protective film to compensate for lithium ion loss and enhance chemical stability, reducing irreversible capacity loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If a lithium metal layer is directly compounded on the surface of the negative electrode plate, then lithium supplementation is achieved, but uniformity of lithium supplementation is poor
Solution Approach 1:
The patent introduces an inorganic lithium compound layer as an intermediary between the lithium metal layer and the electrode active material. This intermediary layer mediates the lithium supplementation process, enabling more uniform distribution of lithium ions to the electrode active material while maintaining the lithium supplementation function. The inorganic lithium compound layer has different lithium ion conductivity characteristics compared to direct lithium metal contact, which promotes uniform lithium ion transport.
2Ease of manufacture
If the substrate is exposed to air, then manufacturing is simplified, but chemical stability deteriorates
Solution Approach 1:
The inorganic lithium compound layer serves as a protective barrier that creates an inert environment for the substrate, preventing direct contact with air and other external environments. This protective layer maintains chemical stability by blocking reactive substances in the air from reaching the substrate, while still allowing for relatively simple manufacturing processes through methods like atomic layer deposition, chemical vapor deposition, or electrochemical deposition.
3Duration of action of moving object
If SEI film ruptures during cycling, then electrode flexibility is maintained, but capacity degradation occurs
Solution Approach 1:
The inorganic lithium compound layer acts as a pre-established protective barrier that cushions against the harmful effects of SEI film rupture. When the SEI film ruptures during battery cycling, this pre-formed protective layer prevents direct exposure of the substrate to harmful substances, thereby reducing capacity degradation and extending cycle life. The layer provides beforehand protection against the inevitable SEI film rupture that occurs during battery operation.
4Ease of manufacture
If active lithium ions are lost during formation, then battery formation is complete, but energy density decreases
Solution Approach 1:
The inorganic lithium compound layer is formed in advance during the electrode manufacturing process, before battery formation. This preliminary formation of the protective layer prevents excessive loss of active lithium ions during the subsequent battery formation process. By having this protective barrier in place beforehand, the system minimizes irreversible lithium ion consumption during formation, thereby preserving energy density while still completing the necessary formation process.
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 electrode material improves energy density and extends cycle life by uniformly supplementing lithium ions and forming a stable protective film, mitigating capacity degradation.
Implementation Method 1
The first inorganic lithium compound layer can isolate the substrate from contact with air, enhancing the chemical stability of the substrate
Implementation Method 2
During the first charge or discharge process, the pre-lithiated electrode active material may release active lithium ions, thereby compensating for the loss of active lithium ions during the battery formation process
Implementation Method 3
the first inorganic lithium compound layer can form a dense, uniform, and stable protective film on the surface of the electrode plate
Data Source
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AI summary
This application provides an electrode material and a preparation method thereof, an electrode plate and a preparation method thereof, a battery, and an electric apparatus. The electrode material includes a substrate and a first inorganic lithium compound layer coated on at least a portion of the surface of the substrate, where the substrate includes a pre-lithiated electrode active material; and the first inorganic lithium compound layer includes at least one of lithium oxide, lithium nitride, lithium carbonate, lithium fluoride, lithium sulfide, or lithium phosphide.