Dual-Basicity Electrolyte for Lithium Metal Dendrite Suppression
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Lithium metal batteries face instability and reduced performance due to the formation of lithium dendrites and a weak solid electrolyte interphase, which affects the battery's capacity, efficiency, and lifespan.
Innovation Solution
An electrolyte solution comprising a lithium salt, a first solvent with high Lewis basicity (β1 ≥ 0.40), and a second solvent with low Lewis basicity (β2 ≤ 0.20) is used to create a solvation environment that promotes the formation of a mechanically strong inorganic-based solid electrolyte interphase on the lithium metal anode.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If lithium metal is used as anode material to achieve high capacity and high energy density, then the battery voltage increases and volume/weight are reduced, but lithium dendrites form and chemical reactivity with electrolyte increases
Solution Approach 1:
The patent changes the chemical composition parameters of the electrolyte by introducing a specific fluorinated cyclic carbonate compound with controlled concentration (5-50 wt% relative to total carbonate solvent). This parameter change modifies the electrolyte's chemical properties to form a stable SEI layer on lithium metal, preventing dendrite formation while maintaining high capacity.
Solution Approach 2:
The patent creates a composite electrolyte system combining fluorinated cyclic carbonate (FEC) with other cyclic carbonate solvents (EC, PC, GC). This composite approach leverages the unique properties of FEC for SEI formation while utilizing complementary properties of other carbonates for ion conductivity and overall electrolyte stability, resolving the contradiction between high capacity and stability.
2Ease of operation
If organic-based solid electrolyte interface is formed on lithium metal anode, then the battery operates, but the interface lacks mechanical strength and delaminates during volume changes
Solution Approach 1:
The patent changes the chemical structure parameter of the electrolyte by using fluorinated cyclic carbonate compounds which contain C-F bonds. This structural modification enables the formation of an inorganic-based SEI layer with enhanced mechanical strength that can withstand the volume expansion and contraction of lithium metal during cycling, preventing delamination while maintaining operational functionality.
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 proposed electrolyte solution enhances the stability of the lithium metal anode, minimizes dendrite formation, and improves the long-term performance and life characteristics of the secondary battery.
Implementation Method 1
capable of establishing a solvation environment in which negative ions exist around lithium ions (Li+) in the electrolyte solution
Data Source
AI summary
Disclosed herein an electrolyte solution and secondary battery comprising the same, the electrolyte solution comprises: a lithium salt; a first solvent; and a second solvent, in which when Lewis basicities of the Kamlet-Taft parameters of the first solvent and the second solvent are represented by β1 and β2, respectively, the β1 is 0.40 or more, and the β2 is 0.20 or less.