Lithium Metal Electrode Rolling with LiF Protective Layer Formation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for preparing lithium metal electrodes are harmful to the environment and human health due to the use of flammable and toxic lubricants, and they fail to effectively suppress dendrite formation during charge and discharge, leading to rapid degradation of battery life and stability.
Innovation Solution
A method involving a fluorine-based solvent and compound lubricant composition is used to form a protective LiF layer on the lithium metal electrode surface during rolling, preventing adhesion and reacting with lithium to form a stable protective layer that suppresses dendrite formation and side reactions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a chain saturated hydrocarbon having 8 or more carbon atoms is used as a lubricant, then adhesion between the rolling roll and lithium is prevented, but handling becomes difficult due to high flammability and it is harmful to the human body
Solution Approach 1:
The patent changes the chemical composition parameters of the lubricant from chain saturated hydrocarbons (8+ carbon atoms) to fluorinated compounds with specific molecular weight ranges (100-100,000 g/mol). This parameter change maintains the lubricating function while eliminating flammability and toxicity issues, as fluorinated compounds have different chemical properties including lower flammability and reduced human health hazards.
Solution Approach 2:
The invention uses a composite lubricant system comprising fluorinated compounds dissolved in fluorinated solvents. This composite approach combines the benefits of fluorinated compounds (non-flammable, low toxicity) with the solvent system that enables proper application and evaporation, creating a complete lubricant solution that addresses both adhesion prevention and safety concerns.
2Ease of manufacture
If a lubricant composition including a polymer having a specific structure is used, then adhesion is prevented, but an aromatic or hydrocarbon solvent with very high flammability and harmfulness is used
Solution Approach 1:
The patent fundamentally changes the solvent type from aromatic or hydrocarbon-based solvents to fluorinated solvents. This parameter change eliminates the flammability and toxicity problems associated with traditional solvents while maintaining the ability to dissolve the polymer lubricant and enable proper coating application.
Solution Approach 2:
The invention converts the previously harmful aromatic or hydrocarbon solvents into beneficial fluorinated solvents that are non-flammable and environmentally friendly. This transformation turns a harmful element into a beneficial one, maintaining the lubricant's functional performance while eliminating safety hazards.
3Ease of manufacture
If a lubricant composition is used, then adhesion is prevented, but a passivation layer including Li2CO3, Li2O, and LiOH is formed which forms dendrites and dead lithium by continuously reacting with electrolyte solution
Solution Approach 1:
The patent changes the chemical composition of the lubricant from conventional polymers to fluorinated compounds with specific molecular weights. This compositional change alters the reaction products formed during electrode preparation, preventing the formation of Li2CO3, Li2O, and LiOH that lead to dendrites, and instead forming a stable protective layer that does not continuously react with the electrolyte.
Solution Approach 2:
The fluorinated lubricant compounds are designed to form a stable, long-lasting protective layer that prevents continuous reaction between the lithium electrode and electrolyte. This stable protective layer replaces the unstable passivation layer that would otherwise form and continuously degrade, improving battery reliability and cycle life.
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 method results in a lithium metal electrode with improved resistance and life characteristics by forming a stable protective layer that prevents dendrite growth and side reactions, enhancing the performance and safety of lithium metal batteries.
Implementation Method 1
a fluorine-based compound on the lithium metal strip to obtain a coated lithium metal strip, and rolling the coated lithium metal strip to obtain the lithium metal electrode... reacting with lithium to form a stable protective layer
Implementation Method 2
rolling the coated lithium metal strip to obtain the lithium metal electrode... use a lubricant to prevent adhesion between the rolling roll and lithium during the preparation
Data Source
AI summary
A method of preparing a lithium metal electrode, wherein the method includes providing a lithium metal strip, and providing a lubricant composition including a fluorine-based solvent and a fluorine-based compound on the lithium metal strip to obtain a coated lithium metal strip; and rolling the coated lithium metal strip to obtain the lithium metal electrode.