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Abstract: The phase relationship of the TbO1.81–Mn3O4–Fe2O3 pseudo-ternary system synthesized at 1200°C was determined using X-ray and neutron diffraction method. Four solid solutions, Mn3−3 x Fe3 x O4 (0.00⩽ x ⩽0.278), Mn3−3 x Fe3 x O4 (0.291⩽ x ⩽0.667), Mn2−2 x Fe2 x O3 (0.89⩽ x ⩽1.00), and (Tb1− y Mn z Fe x )(Fe w Mn1− w )O3 (1−y + x + z ⩽1, 0.00⩽ w ⩽1.00) were found along with six two-phase regions and three three-phase regions. The boundaries were determined by several different methods such as phase disappearing, the Vigard’s law, and the lever rule. [Copyright &y& Elsevier]

The hydrogen storage alloy from spent Ni–MH batteries was regenerated by chemical and smelting method. The alloy regenerated by chemical treatment has the same CaCu5 structure, but the electrochemical capacity is lower than that of the original alloy. When the spent alloy was chemically treated and then smelted by arc-melting, its structure and electrochemical properties could be well recovered. It is found that the discharge properties and lifetime of the regenerated alloy can reach the level of the original alloy. [Copyright &y& Elsevier]

LiNi 1/3 Co 1/3 Mn 1/3 O 2 is successfully coated with MnO 2 by a chemical deposition method. The X-ray diffraction (XRD), scanning electron microscope (SEM) and high resolution transmission electron microscope (HRTEM) results demonstrate that MnO 2 forms a thin layer on the surface of LiNi 1/3 Co 1/3 Mn 1/3 O 2 without destroying the crystal structure of the core material. Compared with pristine LiNi 1/3 Co 1/3 Mn 1/3 O 2 , the MnO 2 -coated sample shows enhanced electrochemical performance especially the rate capability. Even at a current density of 750 mA g −1 , the discharge capacity of MnO 2 -coated LiNi 1/3 Co 1/3 Mn 1/3 O 2 is 155.15 mAh g −1 , while that of the pristine electrode is only 132.84 mAh g −1 in the range of 2.5–4.5 V. The cyclic voltammetry (CV) and X-ray photoelectron spectroscopy (XPS) curves show that the MnO 2 coating layer reacts with Li + during cycling, which is responsible for the higher discharge capacity of MnO 2 -coated LiNi 1/3 Co 1/3 Mn 1/3 O 2 . Electrochemical impedance spectroscopy (EIS) results confirmed that the MnO 2 coating layer plays an important role in reducing the charge transfer resistance on the electrolyte–electrode interfaces. [ABSTRACT FROM AUTHOR]