Safe and recyclable lithium-ion capacitors using sacrificial organic lithium salt

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Lithium-ion capacitors (LICs) integrate lithium-ion battery anodes (graphite) with electric double-layer cathodes (activated carbon).
• A key limitation of current LICs is the absence of an intrinsic lithium-ion source, necessitating a preliminary charging step.
• Existing solutions to this limitation have significant drawbacks.

Purpose of the Study:

• To introduce a novel, self-sufficient lithium-ion source for lithium-ion capacitors.
• To develop a greener and more efficient hybrid energy storage device.
• To explore the potential of lithiated organic materials in energy storage applications.

Main Methods:

• Utilized a novel lithiated organic material, 3,4-dihydroxybenzonitrile dilithium salt, as the lithium-ion source.
• Incorporated this material into a lithium-ion capacitor device.
• Conducted operando charging experiments to assess lithium-ion delivery and device performance.

Main Results:

• The lithiated organic material irreversibly supplied lithium cations to the graphite electrode during initial charging.
• This process did not negatively impact subsequent device operation.
• The method successfully eliminated the need for a separate preliminary charging step.

Conclusions:

• The developed approach restores the low CO2 footprint of lithium-ion capacitors.
• This strategy offers a pathway for designing a broader range of sustainable hybrid energy devices.
• The use of entirely recyclable components in future designs is a significant advantage.