Amorphous carbon a promising material for sodium ion battery anodes: a first principles study

TL;DR

This study uses first principles calculations to compare sodium and lithium storage in amorphous carbon and graphite, revealing amorphous carbon's potential as a sodium-ion battery anode due to favorable sodium insertion sites.

Contribution

It demonstrates that amorphous carbon can host sodium ions effectively, a novel insight for sodium-ion battery anode development.

Findings

Li insertion is thermodynamically favored in both graphite and amorphous carbon.

Na insertion is thermodynamically unfavored in graphite but favorable in amorphous carbon.

Amorphous carbon has multiple strong sodium binding sites, making it suitable for Na-ion batteries.

Abstract

We present a comparative ab initio computational study of sodium and lithium storage in amorphous (glassy) carbon (a-C) vs. graphite. Amorphous structures are obtained by fitting stochastically generated structures to a reference radial distribution function. Li insertion is thermodynamically favored in both graphite and a-C. While sodium insertion is thermodynamically unfavored in graphite, a-C possesses multiple insertion sites with binding energies stronger than Na cohesive energy, making it usable as anode material for Na-ion batteries.