A facile nitrogen-doped carbon encapsulation of CoFe2O4 nanocrystalline for enhanced performance of lithium ion battery anodes

Abstract

Nitrogen-doped (N-doped) carbon encapsulation of CoFe 2 O 4 nanocrystalline is achieved by a simple pressureassisted pyrrole pyrolysis method. The CoFe 2 O 4 /N-doped carbon nanocomposite (CFO/NC) delivers a capacity of 646.2 mAh g -1 after 80 cycles at 0.1 C, exhibits stable cycling performance at various rates from 0.2 to 1.6 C and retains a capacity of 662.8 mAh g -1 as the rate returns back to 0.1 C, showing significantly improved lithium storage reversibility compared to the bare CFO. A different lithiation mechanism of CFO/NC above and below the plateau relative to CFO in the first discharge is analyzed in detail based on the potential profiles and cyclic voltammogram curves. Morphology characterization of the cycled electrodes confirms much better integrity of CFO/NC electrode due to the buffer effect of N-doped carbon coating. Electronic conductivity and electrochemical impedance spectroscopy measurements indicate enhanced electrode reaction kinetics of CFO/NC. All the results contribute to its improved electrochemical performance.

Ultradispersed Cobalt Ferrite Nanoparticles Assembled in Graphene Aerogel for Continuous Photo-Fenton Reaction and Enhanced Lithium Storage Performance

“…On the other hand, the lithium-insertion/extraction properties of the CoFe 2 O 4 /GAs composites as anode material were investigated by galvanostatic charge/discharge measurements over a voltage range of 0.01–3.0 V. Figure 6a shows the charge/discharge curve of CoFe 2 O 4 /GAs at a current density of 0.1 A g −1 . In the first discharge step, the CoFe 2 O 4 /GAs composites present an extended/long voltage plateau at about 0.8 V, followed by a sloping curve down to the cut off voltage of 0.01 V, which is a typical characteristic of voltage trend for the CoFe 2 O 4 electrode 31 46 . A high initial reversible capacity of 1905 mA h g −1 can be derived in the first discharge step, with a corresponding charge capacity of 1037 mA h g −1 based on the weight of the CoFe 2 O 4 /GAs composites.…”

Superior Electrochemical Properties of Nanofibers Composed of Hollow CoFe2O4 Nanospheres Covered with Onion‐Like Graphitic Carbon

“…Multicomponent transition metal oxidesa re converted to fine nanocomposites of single-metalo xides and Li 2 Oi mmediatelya fter the first electrochemical conversion reaction. [5][6][7][8][9][10][26][27][28][29] These singlemetal oxideso ffer ab uffering effect, accommodating the volumec hange during the charge/discharge process. [5][6][7][8][9][10][11][26][27][28] In addition, composition tuning of multicomponent transition metal oxidese nables control of the energy densities and working voltages of electrodes composed of these materials.…”

“…[5][6][7][8][9][10][26][27][28][29] These singlemetal oxideso ffer ab uffering effect, accommodating the volumec hange during the charge/discharge process. [5][6][7][8][9][10][11][26][27][28] In addition, composition tuning of multicomponent transition metal oxidese nables control of the energy densities and working voltages of electrodes composed of these materials. [5,6,[12][13][14]26,[30][31][32][33] Binary transition metal oxide systemsh aving single and multiple phases have been the subjecto fp revious studies, mainly in search of efficient anode materials for lithium storage applications.…”

“…Solid solutions of oxideso fc obalt and iron components have also been studied in the preparation processes of ceramic materials, because cobalt oxides and iron oxides are both promising anode materials for lithium ion batteries (LIBs). [5][6][7][8][9][10][11][12][13][14]24,25,[28][29][30][31][32][33] Nanostructured cobalt ferrite material geometries such as nanotubes, [12] nanosheets, [30] hollow shells, [10,45] and yolk-shells [11,25] have been studied previously, and their cycling performances have been improved by enhancingt he structural stability during repeatedl ithium insertion and desertion processes. Carbon materials such as graphene, [46][47][48][49][50] amorphous carbon, [51] graphitic carbon, [32,52] and carbon nanotubes [53] have also been combined with nanostructured materials to furtheri mprove their electrochemical properties by enhancing their electrical conductivities and structural stabilities.…”

“…Binary transition metal oxide systems having single and multiple phases have been the subject of previous studies, mainly in search of efficient anode materials for lithium storage applications 5–32,34–56. Solid solutions of oxides of cobalt and iron components have also been studied in the preparation processes of ceramic materials, because cobalt oxides and iron oxides are both promising anode materials for lithium ion batteries (LIBs) 5–14,24,25,28–33. Nanostructured cobalt ferrite material geometries such as nanotubes,12 nanosheets,30 hollow shells,10,45 and yolk‐shells11,25 have been studied previously, and their cycling performances have been improved by enhancing the structural stability during repeated lithium insertion and desertion processes.…”