Calcium HMDS Electrolyte for Reversible Metal Anode Cycling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current lithium-based batteries face challenges due to limited resource availability and environmental impacts, necessitating the development of alternative battery technologies, with calcium being a promising candidate but hindered by the lack of suitable electrolytes for efficient calcium metal deposition and dissolution.
Innovation Solution
A calcium salt comprising a Ca2+ cation and hydrocarbon substituted disilazide anions, dissolved in suitable solvents like tetrahydrofuran (THF), enabling high current densities and coulombic efficiency for calcium metal deposition and dissolution, and preventing deleterious reactions with the calcium metal anode by coordinating THF in the Ca2+ coordination sphere.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional electrolytes are used for calcium batteries, then the battery structure can be established, but calcium metal deposition and dissolution cannot proceed efficiently due to lack of suitable electrolytes
Solution Approach 1:
The patent changes the chemical parameters of the electrolyte by using calcium salts with substituted disilazide anions instead of conventional electrolytes. This parameter change enables efficient calcium metal deposition and dissolution while maintaining electrolyte compatibility, directly resolving the technical contradiction between deposition efficiency and electrolyte adaptability
Solution Approach 2:
The patent employs composite electrolyte systems combining calcium salts with substituted disilazide anions and specific solvents (ether, ester, or nitrile). This composite material approach creates an electrolyte that is both compatible with calcium metal and enables efficient deposition/dissolution cycles, addressing the contradiction between reliability and adaptability
2Productivity
If lithium-based batteries are used to meet growing energy demand, then power source availability increases, but resource depletion and environmental damage worsen
Solution Approach 1:
The patent develops calcium battery technology that can serve as a universal replacement for lithium-based batteries. The calcium salt electrolyte system enables calcium batteries to fulfill the same power source function while using abundant calcium resources instead of depleted lithium, resolving the contradiction between productivity and resource loss
Solution Approach 2:
The patent changes the fundamental material parameter from lithium to calcium as the battery metal. This parameter change maintains battery productivity and power source availability while eliminating lithium resource depletion and environmental damage, as calcium is abundant and does not share lithium's environmental extraction issues
3Reliability
If calcium batteries are developed to replace lithium batteries, then resource availability and environmental impact improve, but electrochemical performance suffers due to lack of suitable electrolytes
Solution Approach 1:
The patent changes the electrolyte composition parameters by using calcium salts with substituted disilazide anions in ether, ester, or nitrile solvents. This parameter change simultaneously achieves high current densities (>30 mA/cm2) and high coulombic efficiency (>90%), while maintaining the resource sustainability and environmental compatibility benefits of calcium batteries
Solution Approach 2:
The patent creates composite electrolyte materials combining calcium salts with substituted disilazide anions and specific solvent molecules. This composite approach enables the electrolyte to provide both the environmental sustainability of calcium-based systems and the high electrochemical performance needed for practical productivity
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 calcium salt achieves current densities greater than 30 mA/cm2 and high coulombic efficiency, surpassing previous results, and is stable towards calcium metal, facilitating the use of calcium in rechargeable batteries with improved performance and reduced environmental impact.
Implementation Method 1
the calcium salt dissociates, in solution with at least one solvent, into Ca2+ and HMDS− ions or derivatives thereof
Implementation Method 2
a fraction of THF in the electrolyte that is coordinated in a coordination sphere of the Ca2+ is sufficiently high to prevent deleterious reactions with a calcium metal anode
Implementation Method 3
enabling high current densities and high coulombic efficiency for calcium metal deposition and dissolution
Data Source
AI summary
Disclosed is a calcium salt, Ca(HMDS)2, where HMDS is the hexamethyldisilazide anion (also known as bis(trimethylsilyl)amide), enables high current densities and high coulombic efficiency for calcium metal deposition and dissolution. These properties facilitate the use of this salt in batteries based on calcium metal. In addition, the salt is significant for batteries based on metal anodes, which have higher specific energies than batteries based on intercalation anodes, such as LiC6. In particular, a calcium based rechargeable battery includes Ca(HMDS)2 salt and at least one solvent, the solvent suitable for calcium battery cycling. The at least one solvent can be diethyl ether, diisopropylether, methyl t-butyl ether (MTBE), 1,3-dioxane, 1,4-dioxane, tetrahydrofuran (THF), tetrahydropyran, glyme, diglyme, triglyme or tetraglyme, or any mixture thereof.