Long-Term Cycling Studies on Electrospun Carbon Nanofibers as Anode Material for Lithium Ion Batteries

Abstract

Electrospun carbon nanofibers (CNF) have been prepared at different calcination temperatures for a prolonged time (12 h) derived from electrospun polyacrylonitrile (PAN) membranes. They are studied as anode materials in lithium ion batteries due to their high reversible capacity, improved long-term cycle performance, and good rate capacity. The fibrous morphologies of fresh electrodes and tested samples for more than 550 cycles have been compared; cyclic voltammogram (CV) has also been studied to understand the lithium intercalation/deintercalation mechanism of 1D nanomaterials. CNFs demonstrate interesting galvanostatic performance with fading capacity after the first few cycles, and the capacity increases during long-term cycling. The increasing capacity is observed accompanied by volumetric expansion on the nanofibers' edge. Results of rate capacity have also been explored for all CNF samples, and their stable electrochemical performances are further analyzed by the galvanostatic intermittent titration technique (GITT) and electrochemical impedance spectroscopy (EIS). CNF carbonized at 800 °C is found to have a larger lithium ion storage ability and better cyclic stability than that carbonized at 600 and 1000 °C.

Synthesis of Carbon Nanofibers with Maghemite via a Modified Sol-Gel Technique

“…The fabrication of CNF/ -Fe 2 O 3 with outstanding results has been demonstrated by other researches in which -Fe 2 O 3 is attached to the CNFs outer surface [9]. Nevertheless, electrospinning technique will result in CNFs with a specific morphology (solid fibers) [10]. On the other hand, the use of sol-gel technique has the flexibility to be implemented in different carbon nanomaterials (CNMs) which could bring different results depending on the CNMs used due to differences in morphology allowing the attachment of metal oxides during the synthesis on the inner and outer surfaces of the CNMs in the case of hollow CNFs.…”

“…CNFs, as well as the multiwalled nanotubes (MWNTs) and the singlewalled nanotubes (SWNTs), are the most common components of the nanocomposites [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15]. Industrial products made of reinforced polymers demand improvement of the mechanical properties to preserve the structural integrity and the electrical conductivity to dissipate static electricity [16].…”

“…Previous researches have reported the application of electrospinning technique to fabricate CNF/ -Fe 2 O 3 for Li-ion batteries as high performance anode material. On the other hand, the use of modified sol-gel technique has also been reported using MWCNTs as the base to create a nanohybrid material in order to improve the material properties of polymers [8][9][10][11][12][13][14][15][23][24][25]. Nevertheless, no researches have been reported about the implementation of the same technique using CNFs, which could result in better synthesis results due to the CNF's morphology, in addition to the low cost of the nanohybrid material.…”

Nanostructured electrode materials for lithium-ion and sodium-ion batteries via electrospinning

“…They studied the influence of carbonization temperature on the structural characteristics and electrochemical performances of CNFs, demonstrating the CNFs carbonized at 1000°C showed the highest initial capacity of 450 mA h g −1 at a current rate of 30 mA g −1 but without long-cycle performance. Afterwards, Wu et al [89] realized the long-term cycling of PAN-electrospinning derived CNFs, reaching 400 mA h g −1 after 500 cycles at 0.27 C, and provided reasonable experimental explanation of the gradually increased capacity during long cycle life of CNFs, possible continuous exfoliation of graphene layer in CNFs during Li-ion intercalation/de-intercalation. And Ramakrishna et al [90] successfully prepared free-standing PAN-electrospun CNFs by modifying the carbonization process.…”

Highly Graphitic Carbon Nanofibers Web as a Cathode Material for Lithium Oxygen Batteries

“…CNF webs are simply prepared using electrospinning method, and its graphitization degree was controlled by adjusting pyrolysis temperature [25,26]. The three dimensional network structure of CNF web enables an efficient electron transport along one dimensional geometry and provides uniform pore structure [27].…”