LTO Anode Coating Suppresses Gas Generation
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Solution Overview
Problem
Lithium titanate oxide (LTO) anode materials in lithium-ion batteries generate significant quantities of gas, particularly hydrogen, at elevated temperatures, which is undesirable for commercial use due to safety and longevity concerns.
Innovation Solution
Applying a thin surface coating, such as fluoride-based, carbide-based, or nitride-based coatings with a thickness of less than or equal to 30 nm, via non-aqueous processes like atomic layer deposition, chemical vapor deposition, or physical vapor deposition, to suppress gas formation by minimizing reactions with electrolyte components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If LTO anode material is used in lithium-ion batteries, then cycling stability and rate capability are improved, but gas generation increases significantly
Solution Approach 1:
A thin coating layer (5-50 nm) of aluminum oxide, aluminum fluoride, or lithium fluoride is applied to the LTO surface to act as an intermediary barrier. This coating prevents direct contact between LTO and electrolyte, thereby suppressing gas-generating side reactions while maintaining lithium ion transport capability, thus resolving the contradiction between cycling stability and gas generation.
Solution Approach 2:
A thin film coating (5-50 nm) is applied to the LTO surface to suppress gas generation. The thin film is sufficiently thin to allow lithium ion diffusion while providing enough barrier function to prevent electrolyte decomposition and gas formation, effectively resolving the contradiction between maintaining electrochemical performance and suppressing harmful gas generation.
2Object-generated harmful factors
If coating thickness is increased to suppress gas formation, then gas generation is reduced, but lithium ion transport resistance increases
Solution Approach 1:
The coating thickness is optimized to a specific range (5-50 nm) that balances gas suppression and ion transport. This parameter optimization ensures the coating is thick enough to prevent electrolyte decomposition and gas formation, yet thin enough to maintain low resistance to lithium ion diffusion, resolving the contradiction between gas suppression and energy loss.
3Ease of manufacture
If conventional coating methods are used, then coating application is simple, but coating thickness control precision is insufficient
Solution Approach 1:
Conventional mechanical coating methods are replaced with atomic layer deposition (ALD) technology. ALD uses sequential chemical vapor deposition to achieve atomic-level thickness control (5-50 nm) of the coating layer, precisely controlling coating thickness while maintaining manufacturability, thus resolving the contradiction between ease of manufacture and manufacturing precision.
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 surface coatings significantly reduce gas generation by over 99.5%, extending the battery's life and ensuring safety by maintaining minimal gas levels within the battery for thousands of cycles or up to 3 years, even at elevated temperatures.
Implementation Method 1
The surface coating suppresses gas formation by minimizing reactions with electrolyte components
Implementation Method 2
fluoride-based, carbide-based, or nitride-based coatings... to suppress gas formation by minimizing reactions with electrolyte components
Implementation Method 3
via non-aqueous processes like atomic layer deposition, chemical vapor deposition, or physical vapor deposition
Implementation Method 4
via non-aqueous processes like atomic layer deposition, chemical vapor deposition, or physical vapor deposition
Data Source
AI summary
An electroactive material for use in an electrochemical cell, like a lithium-ion battery, is provided. The electroactive material comprises lithium titanate oxide (LTO) and has a surface coating with a thickness of less than or equal to about 30 nm that suppresses formation of gases within the electrochemical cell. Methods for making such materials and using such materials to suppress gas formation in electrochemical cells are likewise provided.