Multi-interface Combination of Bimetallic Selenide and V₄C₃T MXene for High-Rate and Ultrastable Sodium Storage...

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Sodium-ion batteries (SIBs) offer potential for energy storage but are limited by anode material performance.
• Fast charge/discharge rates and long lifetimes are critical for SIB commercialization.
• Existing anode materials often struggle with stability and durability issues.

Purpose of the Study:

• To address the limitations of current SIB anode materials.
• To develop a novel composite material with enhanced electrochemical performance.
• To improve the cycling stability and charge/discharge rates of SIBs.

Main Methods:

• A multi-interface design strategy was employed using FeSe2/CoSe2 (FCSe) nanoparticles.
• These nanoparticles were anchored on V4C3T MXene nanosheets, acting as conductive substrates.
• The heterogeneous interface between FCSe and V4C3T MXene was engineered to optimize ion transport and mechanical stability.

Main Results:

• The developed C@FCSe@V4C3 electrode demonstrated high-speed charging and discharging capabilities.
• It maintained a high specific capacity of 260.5 mAh g-1 after 15,000 cycles at 10 A g-1.
• Excellent capacity retention of 50.2% was observed at an ultrahigh current density of 20 A g-1, alongside good cycling in fast discharge/slow charge modes.

Conclusions:

• The multi-interface design strategy effectively enhances sodium-ion transport and electrode durability.
• The Fe-Co bonds at the interface mitigate mechanical stress, improving cycling stability.
• This approach offers a promising solution for the reversibility and cycling challenges in selenide anode materials for SIBs, indicating significant commercial potential.