Lithium Metal Composite Electrode Framework Against Dendrite Growth
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Lithium metal-based secondary batteries face issues with electrolyte consumption, lithium dendrite formation, and structural instability due to high lithium activity and uneven solid electrolyte interface reactions, leading to reduced cycle efficiency and safety concerns such as thermal runaway.
Innovation Solution
A lithium metal composite electrode material is developed, incorporating lithium metal particles coated with a lithium-containing conductive layer comprising an inorganic lithium compound and a lithium alloy, which serves as a supporting framework to inhibit irreversible reactions and dendrite growth, enhancing structural and cycle stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If lithium metal is used as negative electrode material to achieve high energy density, then the theoretical specific capacity increases to 3860 mAh/g, but the high activity of lithium metal causes irreversible reactions with electrolyte, consuming electrolyte and reducing cycle efficiency
Solution Approach 1:
A conductive layer comprising carbon material and lithium compound is introduced as an intermediary between the lithium metal particles and the electrolyte. This conductive layer acts as a protective mediator that prevents direct contact between highly active lithium metal and the electrolyte, thereby reducing irreversible reactions and electrolyte consumption while maintaining electrical conductivity for efficient charge transfer.
Solution Approach 2:
The negative electrode is designed as a composite structure consisting of lithium metal particles embedded in a conductive layer that contains both carbon material and lithium compound. This composite material approach combines the high capacity advantage of lithium metal with the protective and conductive properties of the carbon-lithium compound matrix, achieving both high specific capacity and improved cycle efficiency.
2Quantity of substance
If lithium metal is used as negative electrode material to achieve high energy density, then the theoretical specific capacity increases to 3860 mAh/g, but lithium dendrites form during cycling, causing safety issues such as thermal runaway and explosion
Solution Approach 1:
The conductive layer comprising carbon material and lithium compound serves as a protective intermediary that uniformizes lithium ion deposition during charging. This intermediary layer prevents localized stress concentration and uneven plating that lead to dendrite formation, thereby eliminating the safety hazards of thermal runaway and explosion while preserving the high capacity benefits of lithium metal.
Solution Approach 2:
The conductive layer acts as a flexible protective shell surrounding the lithium metal particles. This thin film structure accommodates volume changes during lithium insertion and extraction while maintaining structural integrity, preventing dendrite penetration and providing mechanical protection against safety failures.
3Quantity of substance
If lithium metal is used as negative electrode material to achieve high energy density, then the theoretical specific capacity increases to 3860 mAh/g, but the deposition and dissolution of lithium metal involve significant change in electrode thickness, affecting the stability of battery structure
Solution Approach 1:
The negative electrode is constructed as a composite where lithium metal particles are embedded in a rigid conductive layer containing carbon material and lithium compound. This composite structure provides a stable framework that constrains the lithium metal particles, preventing excessive thickness changes during deposition and dissolution cycles, thereby maintaining electrode structural stability while enabling high capacity.
Solution Approach 2:
The lithium metal is segmented into discrete particles rather than used as a continuous foil. This segmentation, combined with embedding in the conductive layer, distributes volume expansion and contraction stresses across multiple small particles and the surrounding matrix, reducing overall electrode thickness fluctuation and improving structural stability.
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 metal composite electrode material significantly improves the cycle stability and safety of lithium metal secondary batteries by reducing electrolyte consumption and preventing dendrite formation, thereby enhancing both electrical performance and structural integrity.
Implementation Method 1
due to the high activity of lithium metal and the unevenness of a solid electrolyte interface film formed on the surface, an irreversible reaction with an electrolyte easily occurs during the cycle
Implementation Method 2
the lithium metal easily forms dendrites during the cycle. The lithium dendrites separated from a substrate cannot form electronic pathways but form 'dead lithium'
Implementation Method 3
the deposition and dissolution of the lithium metal involve significant change in electrode thickness, which will affect the stability of a battery structure
Data Source
AI summary
Disclosed are a lithium metal composite electrode material for a lithium metal battery, a preparation method for the same, and an electrode, battery, battery module, battery pack and apparatus comprising the same. The lithium metal composite electrode material comprises: lithium metal particles and a lithium-containing conductive layer serving as a supporting framework, the supporting framework being filled with the lithium metal particles; wherein the lithium-containing conductive layer comprises an inorganic lithium compound and a lithium alloy. The lithium metal composite electrode material can solve the problems that, when lithium metal is used as a negative electrode, the electrolyte is easily consumed, and lithium dendrites are easily produced, deposited and dissolved to change electrode thickness, which in turn affects the cycle stability, electrical performance and structural stability of the battery, so as to achieve the purpose of improving the structural stability and cycle stability of the lithium metal electrode.