Lithium Alloy Electrode With LiF Surface Layer for Dendrite Suppression
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Solution Overview
Problem
Lithium electrodes in secondary batteries face issues such as dendrite formation, volume change, and surface oxide film destruction, leading to internal shorts, leakage, and reduced lifespan.
Innovation Solution
A method involving the production of a lithium alloy electrode by melting lithium with a metal fluoride powder to form lithium fluoride (LiF) on the surface, which suppresses dendrite growth and enhances conductivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If a lithium electrode is used to improve energy density, then energy density is improved, but dendrite formation occurs causing internal shorts and reduced reliability
Solution Approach 1:
A lithium alloy electrode comprising lithium and magnesium is introduced as an intermediary solution between pure lithium and conventional electrodes. The magnesium component acts as a mediator that suppresses dendrite formation while maintaining high energy density characteristics of lithium-based electrodes
Solution Approach 2:
The invention uses a composite lithium-magnesium alloy electrode material that combines the high energy density advantage of lithium with the dendrite-suppressing properties of magnesium, creating a composite structure that resolves the contradiction between energy density and reliability
2Duration of action of stationary object
If a lithium alloy electrode is used to improve life characteristics via surface oxide film, then life characteristics are improved, but volume change occurs due to non-uniform plating/stripping
Solution Approach 1:
The invention modifies the surface composition parameters of the lithium alloy electrode by controlling the magnesium content and surface oxide film formation, thereby changing the electrochemical behavior to achieve more uniform lithium plating/stripping and reduced volume change while maintaining extended lifespan
3Duration of action of stationary object
If surface oxide film is formed on lithium alloy electrode to improve lifespan, then lifespan is improved, but side reactions and dendrite formation occur due to electrolyte reaction
Solution Approach 1:
The invention creates a non-uniform surface composition on the lithium alloy electrode with localized regions of different magnesium concentration and oxide film thickness, resulting in areas with enhanced stability that suppress side reactions and dendrite formation while maintaining overall lifespan extension
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 alloy electrode with LiF surface protection improves battery performance and extends the life characteristics of secondary batteries.
Implementation Method 1
the surface of the lithium alloy electrode is coated with a solid electrolyte interphase formed by reacting a metal fluoride with an electrolyte
Implementation Method 2
The lithium secondary battery generates electrical energy by oxidation and reduction reactions when lithium ions intercalates/de-intercalates from the positive electrode and the negative electrode
Data Source
AI summary
A method of manufacturing an electrode for secondary battery is provided. The method includes melting lithium at a first temperature to produce a first melt; stirring a metal fluoride powder together with the first melt at a second temperature to produce a second melt; and producing a lithium alloy electrode with the second melt, wherein the lithium alloy electrode includes lithium fluoride.