YbCl₃ electrode in alkaline aqueous electrolyte with high pseudocapacitance

Area of Science:

• Materials Science
• Electrochemistry
• Inorganic Chemistry

Background:

• Inorganic pseudocapacitors typically use synthetic solid electrodes, leading to poor utilization of pseudocapacitive metal cations.
• Developing electrode materials with high cation utilization is crucial for improving pseudocapacitor performance.

Purpose of the Study:

• To investigate the crystallization transformation of Ytterbium(III) chloride (YbCl3) in alkaline electrolytes for pseudocapacitor applications.
• To explore the effect of crystallization kinetics on the electrochemical performance of YbCl3-based pseudocapacitors.
• To demonstrate a novel strategy for crystallizing electrochemically active compounds with enhanced reactivity.

Main Methods:

• Crystallization of electrochemically reactive Ytterbium oxyhydroxide (YbOOH) colloids via chemical coprecipitation.
• Induction of Faradaic redox reactions to facilitate crystallization.
• Direct utilization of commercial YbCl3 salts as pseudocapacitor electrodes in aqueous electrolytes.

Main Results:

• Achieved a high cation utilization ratio in YbCl3 pseudocapacitor electrodes.
• Demonstrated an ultrahigh specific capacitance of 2210 F/g for YbCl3 pseudocapacitors.
• Simplified electrode fabrication by directly using commercial YbCl3 salts, bypassing complex synthesis.

Conclusions:

• The crystallization transformation strategy offers a novel route to create electrochemically active compounds with high reactivity.
• YbCl3 pseudocapacitors exhibit promising performance for advanced energy storage applications.
• This work advances the understanding of redox mechanisms in ion-based pseudocapacitors.