Diamine-Modified Lithium Salt Electrolyte for Dendrite Suppression
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Lithium-ion batteries with a lithium metal anode face lifetime issues due to dendrite formation, which limits their energy density and safety, and existing solutions like solid electrolytes compromise ionic conductivity and safety.
Innovation Solution
An electrolyte composition comprising a lithium salt, a non-aqueous solvent, and a reaction product of a diamine and a saturated hydroxylated carboxylic acid, which reduces dendrite formation and improves battery safety and performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If a lithium metal anode is used to increase energy density, then the battery capacity increases from 350 mAh/g (graphite) to 3860 mAh/g (lithium metal), but dendrite formation occurs during charging which causes short circuits and reduces battery lifetime
Solution Approach 1:
The patent introduces a diamine compound as an intermediary substance in the electrolyte that mediates between the lithium metal anode and the electrolyte solvent. This diamine forms a protective interface layer that prevents direct harmful interactions while allowing ionic conduction, thereby preventing dendrite formation and enabling the use of high-capacity lithium metal anodes
Solution Approach 2:
The patent modifies the electrolyte composition by adding specific diamine compounds (such as ethylenediamine, diethylenediamine, or triethylenediamine) to change the chemical and physical parameters of the electrolyte system. This alters the decomposition behavior at the anode interface, forming stable protective films that suppress dendrite growth while maintaining high ionic conductivity
2Reliability
If solid electrolytes are used to prevent dendrite formation, then battery safety improves, but ionic conductivity decreases and battery performance is compromised
Solution Approach 1:
The patent creates a composite electrolyte system combining liquid electrolyte components (lithium salt in organic solvent) with diamine compounds that form protective solid-like interface layers. This composite structure maintains the high ionic conductivity of liquid electrolytes in the bulk while forming dendrite-resistant protective films at the electrode interface
3Power
If liquid electrolytes are used to maintain high ionic conductivity, then battery performance is achieved, but safety issues arise due to leakage of flammable and volatile solvents
Solution Approach 1:
The diamine compound acts as an intermediary that forms a protective barrier between the flammable liquid electrolyte and the lithium metal anode. This interface layer prevents direct contact and potential thermal runaway while maintaining ionic conduction, thereby reducing safety hazards associated with flammable solvents
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 electrolyte composition effectively delays or reduces dendrite growth, enhancing battery lifetime and safety while maintaining high ionic conductivity, suitable for lithium-ion batteries with lithium metal anodes.
Implementation Method 1
a reaction product of a mixture comprising: a) at least one diamine; and/or a C 6 to C 18 cycloaliphatic diamine; and/or an aromatic diamine; b) at least one C 3 -C 36 saturated hydroxylated carboxylic acid;
Data Source
Figure 1
AI summary
The present invention relates to an electrolyte composition comprising: - i) at least one lithium salt; - ii) at least one non-aqueous solvent; and - iii) at least one reaction product of a mixture comprising: a) at least one diamine selected from: a1) a C2 to C24 linear aliphatic diamine; and/or a2) a C6 to C18 cycloaliphatic diamine; and/or a3) an aromatic diamine, preferably a C6 to C24 aromatic diamine; b) at least one C3-C36 saturated hydroxy carboxylic acid; c) at least one monoacid selected from the C2 to C18 saturated non-hydroxy linear carboxylic acids; the composition being characterised in that it has a viscosity measured at 23°C of between 101 and 107 mPa.s.