Lithium Metal Anode Halide Coating for Dendrite Suppression
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Solution Overview
Problem
Lithium metal anodes in lithium-ion batteries face challenges with dendrite growth and instability, leading to reduced charge capacity and cycle life, which existing protective layers fail to adequately address.
Innovation Solution
A lithium metal anode protective layer comprising lithium iodide or lithium fluoride, deposited through thermal evaporation, is used to prevent dendrite growth, with specific thickness ranges and deposition conditions optimizing the layer's effectiveness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a protective layer is added to the lithium metal anode, then dendrite growth is prevented and cycle life is improved, but the device complexity and manufacturing process become more complex
Solution Approach 1:
The patent applies preliminary action by depositing the lithium halide protective layer on the lithium metal anode before battery operation begins. This pre-formed protective layer prevents dendrite growth from the start, eliminating the need for complex active dendrite suppression mechanisms during operation. The layer is deposited through thermal evaporation in a vacuum environment, creating a uniform protective barrier that simplifies the overall battery design while maintaining high reliability over extended cycle life.
2Stability of the object's composition
If a protective layer is deposited on the lithium metal anode, then stability is improved, but the manufacturing precision and deposition control become more challenging
Solution Approach 1:
The patent employs parameter changes by carefully controlling the deposition temperature (250-400°C for lithium iodide, 500-900°C for lithium fluoride) and thickness (5-800 nm for LiI, 50-200 nm for LiF) during thermal evaporation. These optimized parameters ensure uniform layer formation with precise thickness control, enhancing anode stability while maintaining manufacturability. The specific temperature and thickness ranges are critical for achieving the desired protective effect without compromising deposition control.
3Reliability
If existing protective layers are used, then some protection is provided, but they fail to adequately prevent dendrite growth and maintain charge capacity
Solution Approach 1:
The patent applies the principle of using a thin, sacrificial protective layer of lithium halide that can be deposited at low cost through thermal evaporation. This thin layer (5-800 nm) acts as a disposable barrier that prevents dendrite growth and maintains charge capacity without requiring thick or complex multi-layer structures. The simplicity and low cost of the lithium halide material make it an effective solution compared to existing protective layers that fail to adequately prevent dendrite growth.
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 protective layer significantly enhances the stability and cycle life of lithium-ion batteries, maintaining specific charge capacity for a larger number of charging/discharging cycles compared to reference batteries without the layer.
Implementation Method 1
depositing the lithium metal anode protective layer comprising the coating composition on the lithium metal anode by conducting a thermal evaporation
Data Source
AI summary
A lithium metal anode protective layer (a single layer or multi layers) including one or more selected from the group consisting of a halide of lithium, such as lithium iodide and lithium fluoride, a lithium metal anode including an anode active layer including lithium metal and the lithium metal anode protective layer including one or more selected from the group consisting of lithium iodide and lithium fluoride, and a method of depositing a lithium metal anode protective layer (a single layer or multi layers) on a lithium metal anode, the method including providing a coating composition including one or more selected from the group consisting of lithium iodide and lithium fluoride on the lithium metal anode, and depositing the lithium metal anode protective layer including the coating composition on the lithium metal anode by conducting a thermal evaporation.