CoFe2O4-graphene nanocomposite as a high-capacity anode material for lithium-ion batteries

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

“…Wang [9] synthesized hollow CoFe 2 O 4 nanospheres, which deliver a capacity of 1,185 mAh g -1 after 50 cycles based on a electrode weight ratio of 55:30:15 (CoFe 2 O 4 /carbon black/polyvinylidene fluoride (PVDF)). Besides, the reported nanocomposites of CoFe 2 O 4 /carbonaceous materials (CoFe 2 O 4 /carbon nanofibers [10] or nanotubes [13], CoFe 2 O 4 /graphene [11], reduced graphene oxide/CoFe 2 O 4 -Co [12]) all exhibit excellent cycling stability and rate capability. However, the preparation methods used in these works, such as sol-gel procedure involves vacuum sublimation of a citrate precursor and a post-annealing at 1,000°C for 24 h [8], hydrothermal or solvothermal method [9,[11][12][13] and combination of sol-gel and electrospinning technique [10], are time-consuming, high-cost and difficult to be controlled, thus significantly hindering the process scale-up.…”

“…Besides, the reported nanocomposites of CoFe 2 O 4 /carbonaceous materials (CoFe 2 O 4 /carbon nanofibers [10] or nanotubes [13], CoFe 2 O 4 /graphene [11], reduced graphene oxide/CoFe 2 O 4 -Co [12]) all exhibit excellent cycling stability and rate capability. However, the preparation methods used in these works, such as sol-gel procedure involves vacuum sublimation of a citrate precursor and a post-annealing at 1,000°C for 24 h [8], hydrothermal or solvothermal method [9,[11][12][13] and combination of sol-gel and electrospinning technique [10], are time-consuming, high-cost and difficult to be controlled, thus significantly hindering the process scale-up. Moreover, it is demonstrated that the nitrogen-doped (N-doped) carbon show better electrochemical performance compared to the non-doped one by inducing more active sites for lithium storage [21,22], enhancing the electronic conductivity of carbon [23,24], and even forming more stable solid electrolyte interphase (SEI) film on N-doped carbon surface [1].…”

“…Alternatively, nano-sized Fe-based spinel metal oxides (MFe 2 O 4 , M=Fe [1][2][3][4][5][6][7], Co [8][9][10][11][12][13], Ni [8,14], Cu [15,16], Zn [17][18][19]), whose reaction mechanism involves the reduction of MFe 2 O 4 into nanoparticles of M 0 and Fe 0 (1-5 nm) [20] embedded in a Li 2 O matrix during lithiation process and reversible oxidation into MO, FeO, and Fe 2 O 3 in the delithiation process, have been intensely investigated as competitive anodes due to their low cost, much higher theoretical capacity (650-1,050 mAh g -1 ) and density (three times that of carbon) [20]. However, these materials suffer from poor capacity retention due to the large volume variation and severe particle aggregation during the conversion process, which finally lead to pulverization of the electrode and rapid capacity fading [5-7, 15, 18].…”

“…Carbonaceous materials coating has been reported to be an effective way to overcome these problems. The coated carbon or graphene act as an elastic layer to compensate for the volume change and prevent the agglomeration problem, as well as act as a conductive layer facilitating the transport of Li-ions and electrons, thus extending the cycling life of the electrode [5][6][7][10][11][12][13].…”

Synthesis of graphene–NiFe2O4 nanocomposites and their electrochemical capacitive behavior

“…Recently, much work have been done on hybrid metal hydroxides or crystalline ferrites (such as NiAl-layered double hydroxide-graphene, CoAllayered double hydroxide-graphene, MnFe 2 O 4 , CoFe 2 O 4 and so on), because of their pseudocapacities. [23][24][25][26][27][28] Besides, spinel transition metal oxides (AB 2 O 4 ) with two metal elements provide the feasibility to tune the energy density and working voltage by varying the metal content. 29,30 Among the AB 2 O 4 , it was reported that NiFe 2 O 4 had been applied as anode material for LIBs with excellent electrochemical properties.…”