Reversible Electrochemical Lithium-Ion Insertion into the Rhenium Cluster Chalcogenide-Halide Re₆Se₈Cl₂

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Cluster-based materials offer unique electronic and ionic properties.
• Two-dimensional ternary materials are promising for advanced applications.
• Re₆Se₈Cl₂ exhibits cluster-cluster bonding and ion insertion capabilities.

Purpose of the Study:

• To investigate the electrochemical performance of the Re₆Se₈Cl₂ material for energy storage.
• To evaluate the electron transfer capacity and cycling stability of the Li/Re₆Se₈Cl₂ system.
• To understand the degradation mechanisms at higher electron transfer equivalents.

Main Methods:

• Electrochemical testing of the Li/Re₆Se₈Cl₂ system.
• Cyclic voltammetry and galvanostatic cycling to assess electron transfer.
• Analysis of the solid-electrolyte interface formation.

Main Results:

• Reversible electron transfer from 1 to 3 electron equivalents (ee) was achieved at high current densities (88 mA/g).
• Capacity degradation was observed upon cycling to 4 ee over 50 cycles.
• Formation of an organic solid-electrolyte interface was identified as the cause of degradation.

Conclusions:

• The cluster-based Re₆Se₈Cl₂ material shows potential for energy storage applications.
• The material exhibits structural stability and high rate capability for reversible electron transfer.
• Understanding interface formation is crucial for optimizing performance at higher capacities.