Jianhang Huang

Zn–Al layered double oxides as high-performance anode materials for zinc-based secondary battery

In this work, Zn–Al layered double oxides (Zn–Al-LDO) were prepared via a facile hydrothermal method, followed by calcination treatment in an air atmosphere, and evaluated as anode materials of Zn/Ni batteries. The morphology and structure of as-prepared Zn–Al-LDO and its precursor Zn–Al layered double hydroxide (Zn–Al LDH) were investigated through Fourier transform infrared spectra (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Compared to the Zn–Al-LDH precursor, Zn–Al-LDO possesses higher discharge capacity, better reversibility and longer cycle life. The discharge capacity of Zn–Al-LDO remains about 460 mA h g−1 after 1000 cycles. In particular, good rate performance can be observed for a Zn–Al-LDO electrode. The superior properties could be ascribed to improved charge conductivity and the absence of carbonate anions, which make migration of hydroxyl anions smooth to meet the requirements of the electrochemical reaction of the electrode.

A novel ZnO@Ag@Polypyrrole hybrid composite evaluated as anode material for zinc-based secondary cell.

A novel ZnO@Ag@Polypyrrole nano-hybrid composite has been synthesized with a one-step approach, in which silver-ammonia complex ion serves as oxidant to polymerize the pyrrole monomer. X-ray diffraction (XRD) and infrared spectroscopy (IR) show the existence of metallic silver and polypyrrole. The structure of nano-hybrid composites are characterized by scanning electron microscope (SEM) and transmission electron microscope (TEM), which demonstrates that the surface of ZnO is decorated with nano silver grain coated with polypyrrole. When evaluated as anode material, the silver grain and polypyrrole layer not only suppress the dissolution of discharge product, but also helps to uniform electrodeposition due to substrate effect and its good conductivity, thus shows better cycling performance than bare ZnO electrode does.

Preparation and stability study of potassium ferrate (VI) coated with phthalocyanine for alkaline super-iron battery

The potassium ferrate (VI) coated with phthalocyanine (H2Pc) was successfully prepared via a facile co-precipitation process. Scanning electron microscopy and Fourier transform infrared spectrum revealed that K2FeO4 had been coated with H2Pc particles. When evaluated as cathodic material for alkaline super-ion battery, the effects of H2Pc coating on the electrochemical stability of K2FeO4 electrodes upon prolonged immersion time were investigated by galvanostatic discharge test, open-circuit potential measurements, and electrochemical impedance spectroscopy. The results show that the decomposition of K2FeO4 in electrolyte is obviously suppressed by H2Pc coating with a short immersion time, which could enhance the discharge capacity of electrodes. Furthermore, the open-circuit potential of the H2Pc-coated K2FeO4 electrode is higher than that of the bare K2FeO4 electrode, which indicates the improvement of anticorrosive ability. In addition, the ability of charge transfer between electrode and electrolyte is enhanced by H2Pc coating due to the inhibition on formation of Fe (III) layer, but the improved performance will decline upon prolonged immersion time.