3D Hierarchical Graphene‐CNT Anode for Sodium‐Ion Batteries: a First‐Principles Assessment

Abstract

A thermodynamically and kinetically stable 3D hierarchical carbonaceous nanostructure is constructed to examine its potential as an anode for sodium-ion batteries (SIBs). Heptagonal and quadrilateral staggered carbon rings are formed where the graphite layers and the CNT interconnect vertically. Based on first-principles calculations, such a graphite-CNT hybrid with expanded interlayer spacing allows effective binding to Na atoms and contributes a high specific capacity of 324.3 mAh g −1 . It maintains a great electronic conductivity for both pristine and Na-adsorbed graphite-CNT along the expanded graphite layers, and constructs a 3D electronic transport network when a large number of Na atoms are adsorbed. This hierarchical nanostructure predicts a fast inner 3D Na-ion transport network, with energy barriers of 0.56 and 0.50 eV along the expanded graphite layer and the CNT channel, respectively. This research manifests the feasibility of obtaining well-performed graphite-based anodes for SIBs through purposeful microcosmic morphology modification.

C-57 nanotube: electronic, optical, and mechanical properties by DFT calculations

“…Where n indicates the number of adsorbed Li or Na atoms on C-57 nanotubes, F is Faraday constant (26801 mAh g −1 ), and M represents the molar mass of C-57 nanotubes. The suitable theoretical Li or Na storage capacity of 278.92 mAh g −1 has been obtained, which is more than compared to the pseudo hexagonal Nb 2 O 5 -decorated carbon nanotubes (203 mAh g −1 ) [34], the nanocarbon spheres (230 mAh g −1 ) [35], and less than the straight carbon nanotubes (370 mAh g −1 ) [36,37] and the BC 2 N/Blu-Pn system (763 mAh g −1 ) [38].…”