Ni-Bridged Biphasic Molybdenum Carbide Interfaces: A Synergistic Catalyst for High-Performance Lithium-Selenium...

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• High-performance lithium-selenium (Li-Se) batteries require effective transition metal catalysts.
• Developing catalysts that enhance electrochemical reversibility under high current operation is crucial for advanced energy storage.

Purpose of the Study:

• To design and investigate a novel Ni-bridged biphasic molybdenum carbide (Mo2C) catalyst for Li-Se batteries.
• To enhance the catalytic activity and electrochemical reversibility of Li-Se batteries through synergistic integration of catalytic and conductive functions.

Main Methods:

• Synthesis of a Ni-bridged biphasic Mo2C catalyst with a multi-interface structure.
• Electrochemical characterization of the catalyst's performance in Li-Se batteries, including cycling stability and rate capability.
• Analysis of the synergistic effects of adsorption, desorption, and catalysis on selenium conversion pathways.

Main Results:

• The Ni-Mo2C catalyst exhibits abundant active sites and significantly improves electrochemical reversibility.
• Synergistic integration of catalytic and conductive functions facilitates rapid deposition and conversion of Se/Li2Sex, preventing electrode passivation.
• The catalyst promotes rapid conversion of long-chain polyselenides and solid-solid transformation, achieving full-process catalytic conversion.

Conclusions:

• The rationally designed Ni-Mo2C catalyst effectively enhances Li-Se battery performance, offering excellent cycling stability and high-rate capability.
• The synergistic adsorption/desorption/catalysis mechanism enables a fast solid-solid conversion pathway, crucial for advanced Li-Se battery technology.
• The catalyst demonstrates potential for high-Se loading applications, achieving 400 mAh g-1 at 0.1 C with 5.6 mg cm-2 Se loading.