Effect of Pores in Hollow Carbon Nanofibers on Their Negative Electrode Properties for a Lithium Rechargeable Battery

Abstract

The effect of pores in hollow carbon nanofibers (HCNFs) on their electrochemical performance is investigated because the carbon shell itself acts as a reservoir for accommodating Li-ions through intercalation and simultaneously becomes a transport medium through which Li-ions migrate into the core materials in HCNFs. Porous HCNFs (pHCNFs) are prepared by the coaxial electrospinning of a sacrificial core solution and an emulsified shell solution containing sacrificial islands for pore generation. After a thermal treatment, a systematic study is carried out to relate the resulting pore size in pHCNFs to the sacrificial islands in the emulsified shell. As the pores are introduced in pHCNFs, their initial capacity and reversible capacity rate are proved to increase significantly to 1003 mAhg(-1) and 61.8%, respectively, compared to those (653 mAhg(-1) and 53.9%) of nonporous HCNFs. The increased pore size and expanded graphene layers are believed to facilitate lithium insertion/extraction behavior.

Large-scale synthesis of ordered mesoporous carbon fiber and its application as cathode material for lithium–sulfur batteries

“…The major stream of Li-S research has focused on the design "inside" the cathode, confining sulfur within various kinds of porous matrixes, such as porous carbon [10][11][12][13][14][15][16] or graphene [17][18][19], or applying surface coatings of conductive polymer [20][21] or metal oxides such as TiO2 [22] or Al2O3 [23] to act as a physical barrier to prevent the soluble polysulfides from dissolving in the organic electrolyte.…”

Electrospun carbon-based nanostructured electrodes for advanced energy storage – A review

“…Using sacrificial components has been regarded as an efficient way to create nanostructured pores in the final materials where the size of these pores can be easily controlled by tailoring the corresponding parameters of the original components. These sacrificial components can be classified to two typical categories: (i) sacrificial inorganic phases such as SiO 2 [71] and Ni particles [15] and (ii) sacrificial polymers such as PMMA [72], PLLA [73], Styrene-co-Acrylonitrile (SAN) [74], and Nafion [75]. The first is to use suitable precursors for producing inorganic nanoparticles, followed by an etching process to mainly produce micro-and meso-pores.…”

Porous hollow carbon nanofibers derived from multi-walled carbon nanotubes and sucrose as anode materials for lithium-ion batteries

“…23,24 Meanwhile, fabrication of thin hollow CNFs is still rare, 25 since most of the reported hollow CNFs have a relatively large particle size of over 100 nm. 4,[26][27][28] Therefore, coating a non-graphitic carbon layer on MWCNTs to construct thin hollow CNFs with diameters less than 100 nm is highly expected to enhance the electrochemical properties.…”