Improving the Sodium Storage Behavior of Anthracite with a Tailored Interface Layer

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Coal-derived hard carbon (C-HC) is a cost-effective material for energy storage.
• Low initial coulombic efficiency (ICE) and reversible capacity limit C-HC's large-scale application.

Purpose of the Study:

• To fabricate enhanced hard carbon matrices using anthracite as a precursor.
• To improve the electrochemical performance of hard carbon for sodium-ion batteries through interface engineering.

Main Methods:

• Optimized carbonization of anthracite.
• Liquid-phase impregnation with solvated asphalt to create nanointerface layers (AN@LQ).
• Electrochemical evaluation, cyclic voltammetry, quasi-in situ EIS, and XPS analysis.

Main Results:

• AN@LQ achieved a reversible specific capacity of 283 mAh g^-1 (11% enhancement over unmodified HC).
• ICE improved from 74% to 88%, with 89% capacity retention after 100 cycles.
• Enhanced sodium ion diffusion coefficient attributed to the artificial interface layer.

Conclusions:

• The artificial interface layer effectively enhances the performance of coal-derived hard carbon.
• This cost-effective strategy offers a pathway for scaling up sodium-ion batteries.
• Novel insights into interface construction for hard carbon materials.