Electrochemical Performance of Hybrid Cationic Aqueous-Based Rechargeable Battery with Different Current Collectors and Electrolytes

Different zinc foils as anode current collectors by electrowinning in various electrolytes with additives were prepared, which were evaluated through X-ray diffraction (XRD), scanning electron microscopy (SEM), float charge, and Tafel curve tests. The effect of different cathode current collectors, electrolytes, and the as-prepared zinc foils as the anode on the coulombic efficiency and the cycling performance of aqueous batteries were investigated. The results indicate that the initial coulombic efficiency and discharge capacity of the battery with 1 mol/L ZnSO4 and 2 mol/L Li2SO4 are 94.31% and 105.7 mAh/g using graphite as the current collector, which are much higher than 68.20% and 71.0 mAh/g using conductive polyethylene, respectively, attributed to the smaller polarization and electrochemical transfer impedance (Rct) of the former. However, the capacity retention of the latter is much higher than that of the former, especially using the high-concentration-lithium-based hybrid electrolyte, of which it is up to 74.63% even after 500 cycles. Moreover, the cycling performance of a battery with as-prepared zinc foil adding thiourea and gelatin into electrolyte during electrowinning is much better than that without additives, which is due to the smaller corrosion rate and side reaction.

Photoluminescence and electrical properties of bidirectional ZnO nanowires on Zn foils via a thermal oxidation method

ZnO nanowires were directly grown on ductile zinc foils through a two-step process. Zn foils were fabricated from a mixture of Zn and ZnO powders; and ZnO NWs were produced using thermal oxidation at temperatures of 300–600 °C.

ROOM-TEMPERATURE FERROMAGNETIC PROPERTIES OF Co-DOPED ZnO NAOROD ARRAYS

Co -doped ZnO rod arrays were fabricated on zinc foils by a hydrothermal method. X-ray diffraction results indicate that the samples have wurtzite crystalline structure without metallic Co or other secondary phases detected. The nanorod arrays exhibit room-temperature ferromagnetic behavior for different Co concentration. The influence of Co on the magnetic properties of ZnO was studied by the first-principles calculations. The exchange interaction between local spin-polarized electrons and conductive electrons is proposed as a cause of the room-temperature ferromagnetism.

HIERARCHICAL Zn5(OH)6(CO3)2 STRUCTURE ASSEMBLED IN AN AQUEOUS SOLUTION

Hydrothermal technique is demonstrated for achieving Zn 5( OH )6( CO 3)2 microstructure consisting of nanosheets on zinc foils in the presence of formamide. Formamide concentration and reaction temperature have significant influences on the size and shape of hierarchical Zn 5( OH )6( CO 3)2 structures. A self-assembly mechanism is proposed to explain the growth of Zn 5( OH )6( CO 3)2 microstructure, which can be transformed into sheet-like dense ZnO architectures without loss of the shape features by calcining in air.