Shangbin Sang

A high-rate cathode material hybridized by in-site grown Ni–Fe layered double hydroxides and carbon black nanoparticles

A facile hydrothermal fabrication was applied to hybridize in-site grown flower-like Ni–Fe layered double hydroxides (Ni–Fe LDHs) and carbon black (CB) nanoparticles. The well-conductive CB particles were dispersed homogeneously onto the petals of the Ni–Fe LDH flowers via a combination of electrostatic forces and ripening growth, and remarkably promoted the charge-transfer capability of the LDHs. The hybridized Ni–Fe LDH/CB composite electrode exhibited excellent rate performance that retained both a high capacity and steady cycle life at a large charge–discharge current, and was highly competitive serving as a high-rate alkaline battery cathode.

Effect of preparation routes on activity of Ag-MnOx/C as electrocatalysts for oxygen reduction reaction in alkaline media

Abstract The effect of preparation routes on the physical characteristics and activity of the Ag-MnOx/C composites toward the oxygen reduction reaction (ORR) in alkaline media were studied by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), energy-dispersion spectroscopy (EDS) as well as scanning electron microscopy (SEM) and electrochemical techniques. The results show that more Ag and Mn species present on the surface of the Ag-MnOx/C composite prepared by two-step route (Ag-MnOx/C-2) compared to the one prepared by one-step route (Ag-MnOx/C-1), which contributes to its superior activity toward the ORR. The higher electron transfer number involved in the ORR can be observed on the Ag-MnOx/C-2 composite and its specific mass kinetic current at −0.6 V (vs Hg/HgO) is 46 mA/μg, which is 23 times that on the Ag/C. The peak power density of zinc–air battery with the Ag-MnOx/C-2 air electrode reaches up to 117 mW/cm2.

Solvothermal hybridization of LiMn1/3Ni1/3Co1/3O2 and reduced graphene oxide to promote lithium-ion cathode performance

A facile solvothermal solution has been introduced to hybridize pre-sintered LiMn1/3Ni1/3Co1/3O2 (LMNC) nanocrystals and ethylene glycol reduced graphene oxide (EGRGO) nanosheets. Compared with the liquid-based growth of metallic oxide on graphene sheets, this approach not only ensures a high crystallinity of the LMNC particles from pre-sintering, but also realizes the intimate coupling of RGO with LMNC via covalent metal–oxygen bonds. The as-prepared EGRGO/LMNC nanocomposites have been characterized and confirmed by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and thermogravimetric analysis (TGA). The fabricated EGRGO/LMNC composite electrodes have been investigated using cyclic voltammetry (CV), galvanostatic charge–discharge (GCD), and electrochemical impedance spectroscopy (EIS). The results reveal the markedly improved reversibility of the EGRGO/LMNC cathode toward lithium ion intercalation/extraction, which results in a large discharge capacity, high coulombic efficiency, and excellent rate performance. The elevated electrochemical capability of the EGRGO/LMNC cathode material is accounted for the better electrical conduction of the EGRGO nanosheets, highly stable crystal structure of the pre-sintered LMNC particles, and firm construction of the EGRGO/LMNC composite due to solvothermal hybridization.