Electrochimica Acta, Vol.240, 456-465, 2017
Synthesis of novel spherical Fe3O4@Ni3S2 composite as improved anode material for rechargeable nickel-iron batteries
Fe3O4@Ni3S2 microspheres as a novel alkaline anode material have been successfully fabricated through a four-step process for the first time. In this composite, Ni3S2 nanoparticles are coated tightly on the surface of Fe3O4 microspheres. Compared with the pure Fe3O4 and Fe3O4@NiO microspheres, the proposed Fe3O4@Ni3S2 delivers a significantly improved high-rate performance and enhanced cycling stability. At a high discharge rate of 1200 mA g(-1), the specific capacity of the Fe3O4@Ni3S2 is similar to 481.2 mAh g(-1) in comparison with similar to 83.7 mAh g(-1) for the pure Fe3O4. After 100 cycles at 120 mA g(-1), the Fe3O4@Ni3S2 can achieve a capacity retention of 95.1%, while the value for the pure Fe3O4 electrode is only 52.5%. The favorable electrochemical performance of the Fe3O4@Ni3S2 is mainly attributed to the beneficial impact of Ni3S2. The Ni3S2 layer as a useful additive is significantly conducive to lessening the formation of Fe (OH)(2) passivation layer, enhancing the electronic conductivity, improving the reaction reversibility and suppressing the hydrogen evolution reaction of the alkaline iron anode. Owing to its outstanding electrochemical properties, we believe that the novel Fe3O4@Ni3S2 composite is potentially a promising candidate for anode material of alkaline iron-based batteries. (C) 2017 Elsevier Ltd. All rights reserved.
Keywords:Anode material;Nickel-iron batteries;Cycling stability;Electrochemical properties;Nickel sulfide