Facilitating Rapid Na⁺ Storage through MoWSe/C Heterostructure Construction and Synergistic Electrolyte Matching...

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Sodium-ion devices face challenges with carrier diffusion and electrode fragmentation in transition metal selenide anodes, limiting power density and cycle life.
• Developing robust anode materials is critical for advancing high-performance sodium-ion energy storage systems.

Purpose of the Study:

• To engineer Mo/W-based metal-organic frameworks and synthesize MoWSe/C heterostructures for enhanced sodium-ion anodes.
• To investigate the electrochemical performance and ion transport mechanisms of the novel MoWSe/C electrode in ether-based electrolytes.
• To provide insights into the structural design of conversion anodes for high capacity, fast kinetics, and long cycle stability.

Main Methods:

• One-step synthesis of a Mo/W-based metal-organic framework.
• Facile selenization and carbonization strategy to create MoWSe/C heterostructures.
• Physical characterization and theoretical calculations to analyze structural and electrochemical properties.
• Electrochemical testing of Na half-cells and sodium-ion capacitors.

Main Results:

• The synthesized MoWSe/C electrode exhibited significant structural advantages and excellent electrochemical performance.
• Ether-based electrolytes facilitated stable solid electrolyte interfaces and prevented electrolyte decomposition.
• The Na half-cell achieved a specific capacity of 347.3 mA h g^-1 after 2000 cycles at 10 A g^-1.
• The sodium-ion capacitor demonstrated ~80% capacity retention after 11,000 cycles at 3800 W kg^-1.

Conclusions:

• MoWSe/C heterostructures synthesized via a facile strategy offer superior rate capability and long-cycle stability for sodium-ion energy storage.
• Ether-based electrolytes are beneficial for constructing stable interfaces and enhancing the performance of conversion anodes.
• The study provides a mechanistic understanding and a design reference for developing advanced anodes in sodium-ion devices.