Sodium Ion Insertion in Hollow Carbon Nanowires for Battery Applications

Abstract

Hollow carbon nanowires (HCNWs) were prepared through pyrolyzation of a hollow polyaniline nanowire precursor. The HCNWs used as anode material for Na-ion batteries deliver a high reversible capacity of 251 mAh g(-1) and 82.2% capacity retention over 400 charge-discharge cycles between 1.2 and 0.01 V (vs Na(+)/Na) at a constant current of 50 mA g(-1) (0.2 C). Excellent cycling stability is also observed at an even higher charge-discharge rate. A high reversible capacity of 149 mAh g(-1) also can be obtained at a current rate of 500 mA g(-1) (2C). The good Na-ion insertion property is attributed to the short diffusion distance in the HCNWs and the large interlayer distance (0.37 nm) between the graphitic sheets, which agrees with the interlayered distance predicted by theoretical calculations to enable Na-ion insertion in carbon materials.

Multidimensional Evolution of Carbon Structures Underpinned by Temperature‐Induced Intermediate of Chloride for Sodium‐Ion Batteries

“…With improved carbonization temperature, the (002) peaks' positions were shifted toward a low angel (from 23.5 o to 22.3 o ), which are calculated as the lattice expands gradually from 0.373 to 0.397 nm, facilitating the insertion–extraction of Na + 37. In Table 1, the value of L c / d (002) is found from 4.9 to 5.9, indicating the increased interlayer in the graphitic domain,22 which agrees well with the analysis of TEM in Figure 4. The Raman spectra of CNF‐400/500/600/700 were displayed in Figure 5B, showing the improved degree of graphite form the variation of I D / I G , which is beneficial for the shuttling of sodium ions at high‐rate current densities 38.…”

Large‐Area Carbon Nanosheets Doped with Phosphorus: A High‐Performance Anode Material for Sodium‐Ion Batteries

“…[[qv: 7b,11a,23]] The bumps at ≈0.6 V during the cathodic process from second to fourth cycle should be ascribed to the reversible sodiation process in the surface functional groups 17. The cathodic peaks situated around 0.01 V is stemming from Na + insertion into carbonaceous materials 4, 7, 17. Broad anodic peaks from 0.1 to 0.6 V in all the four cycles tells desodiation process taken place in a wide potential range.…”

“…Because Na + ions cannot be easily intercalated into the layers of graphite due to larger radius of Na + , resulting in a low capacity of 31 mAh g −1 , conventional graphite might not be suitable for SIBs 3. However, various amorphous carbon materials including hollow nanostructured carbons,4 carbon nanospheres,5 carbon nanofibres,6 carbon nanosheets,7 porous carbons,8 hard carbon,9 graphene,10 and heteroatom‐doped carbon materials11 are being investigated as anode for SIBs in full swing, benefiting from disordered nanodomains with randomly oriented graphene layers and voids between these domains, which can provide rich active sites for storing Na + 9, 12. Unfortunately, lots of amorphous carbon‐based anode materials are accompanied with low initial columbic efficiency and poor specific capacity at high current density.…”

Sodium‐Ion Batteries: Improving the Rate Capability of 3D Interconnected Carbon Nanofibers Thin Film by Boron, Nitrogen Dual‐Doping

“…The peaks at about 0.01 V correspond to Na‐ion insertion in BN‐CNFs 47. The CV peaks located at about 0.01 V is ascribed to Na + insertion/extraction in the interlayer of the BN‐CNFs 47, 48. A clear peak at 0.11 V in the 1st charge process is observed, corresponding to sodium extraction from the nanopores of BN‐CNFs 11.…”