Facile green synthesis of a Co3V2O8 nanoparticle electrode for high energy lithium-ion battery applications.

In the present study, a metal-organic framework (MOF) derived from a facile water-assisted green precipitation technique is employed to synthesize phase-pure cobalt vanadate (Co3V2O8, CVO) anode for lithium-ion battery (LIB) application. The material obtained by this eco-friendly method is systematically characterized using various techniques such as powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and N2 adsorption-desorption measurements. By using as an anode, an initial discharge capacity of 1640mAhg-1 and a reversible capacity of 1194mAhg-1 are obtained at the applied current densities after the 240th cycle (2Ag-1 for 200 cycles followed by 0.2Ag-1 for 40 cycles). Moreover, a reversible capacity as high as 962mAhg-1 is retained at high current densities even after 240 cycles (4Ag-1 for 200 cycles followed by 2Ag-1 for 40 cycles), revealing the long life stability of the electrode. Significantly, CVO anode composed of fine nanoparticles (NPs) registered a substantial rate performance and reversible specific capacities of 275, 390, 543 and 699mAhg-1 at high reversibly altered current densities of 10, 5, 2, and 1Ag-1, respectively.

One-Step Pyro-Synthesis of a Nanostructured Mn3 O4 /C Electrode with Long Cycle Stability for Rechargeable Lithium-Ion Batteries.

A nanostructured Mn3 O4 /C electrode was prepared by a one-step polyol-assisted pyro-synthesis without any post-heat treatments. The as-prepared Mn3 O4 /C revealed nanostructured morphology comprised of secondary aggregates formed from carbon-coated primary particles of average diameters ranging between 20 and 40 nm, as evidenced from the electron microscopy studies. The N2 adsorption studies reveal a hierarchical porous feature in the nanostructured electrode. The nanostructured morphology appears to be related to the present rapid combustion strategy. The nanostructured porous Mn3 O4 /C electrode demonstrated impressive electrode properties with reversible capacities of 666 mAh g-1 at a current density of 33 mA g-1 , good capacity retentions (1141 mAh g-1 with 100 % Coulombic efficiencies at the 100th cycle), and rate capabilities (307 and 202 mAh g-1 at 528 and 1056 mA g-1 , respectively) when tested as an anode for lithium-ion battery applications.

Hierarchical porous anatase TiO2 derived from a titanium metal-organic framework as a superior anode material for lithium ion batteries.

Hierarchical meso-/macroporous anatase TiO2 was synthesized by the hydrolysis of a titanium metal-organic framework precursor followed by calcination in air. This unique porous feature enables the superior rate capability and excellent cycling stability of anatase TiO2 as an anode for rechargeable lithium-ion batteries.