Search

Abstract In the present study, V3O5 microcrystals that synthesized via vacuum calcination are employed as anodes for lithium‐ion batteries (LIBs) for the first time. Despite the widely observed sluggish reaction kinetics and poor cycling stability in most micro‐sized transition metal oxides, the V3O5 microcrystals exhibit excellent rate capability (specific capacities of 144 and 125 mAh g−1 are achieved at extremely high current densities of 20 and 50 A g−1, respectively) and long‐term cycling performance (specific capacity of 117 mAh g−1 is sustained over 2000 cycles at 50 A g−1). It is ascribed to the three‐dimensional open‐framework structure of the V3O5 microcrystals as a major factor in dictating the fast reaction kinetics (lithium diffusion coefficient: ~10−9 cm2 s−1). In addition, significant insight into the reaction mechanism of the V3O5 microcrystals in concomitant its phase evolution are obtained from ex‐situ XRD study, revealing that the V3O5 microcrystals undergo intercalation reaction with insignificant structural change in response to lithiation/delithiation.

We report the synthesis of ultrathin S-doped MoSe[sub 2] nanosheets demonstrating enhanced HER catalysis with a low onset overpotential of 90 mV and a Tafel slope of 58 mV per decade. We attribute the improved catalytic effects to the proliferation of unsaturated HER active sites in MoSe[sub 2] resulting from S-doping. [ABSTRACT FROM AUTHOR]

Transition metal-nitrogen/carbon (M-N/C, M = Fe, Co) catalysts are synthesized using environmentally friendly histidine-tag-rich elastin protein beads, metal sulfate and water soluble carbon nanotubes followed by post-annealing and acid leaching processes. The obtained catalysts are used as cathode materials in lithium-O2 batteries. It has been discovered that during discharge, Li2O2 nanoparticles first nucleate and grow around the bead-decorated CNT regions (M-N/C centres) and coat on the catalysts at a high degree of discharge. The Fe-N/C catalyst-based cathodes deliver a capacity of 12 441 mAh g−1 at a current density of 100 mA g−1. When they were cycled at a limited capacity of 800 mAh g−1 at current densities of 200 or 400 mA g−1, these cathodes showed stable charge voltages of ∼3.65 or 3.90 V, corresponding to energy efficiencies of ∼71.2 or 65.1%, respectively. These results are considerably superior to those of the cathodes based on bare annealed CNTs, which prove that the Fe-N/C catalysts developed here are promising for use in non-aqueous lithium-O2 battery cathodes. [ABSTRACT FROM AUTHOR]