The corrosion behavior of tantalum in tetraethyl ammonium chloride （TEA） ethanol solutions was investigated using potentiodynamic polarization, cyclic voltammetry, and impedance techniques along with scanning electr...The corrosion behavior of tantalum in tetraethyl ammonium chloride （TEA） ethanol solutions was investigated using potentiodynamic polarization, cyclic voltammetry, and impedance techniques along with scanning electron microscopy （SEM）. At the early stage of scanning, the current density in the cyclic voltammetry curves very slowly increased because of the presence of a thin oxide film on the electrode surface. Pitting corrosion then occurred as a result of the passivity breakdown caused by the aggressive attack of the Cl^- anions. SEM images showed the growth process of the pits on the electrode surface. The pitting potential decreased with the increase in TEA concentration but increased with the increase in water concentration. The apparent activation energy of the electrochemical reaction was 36 kJ/mol. The impedance spectra exhibited two time constants for all the potentials. Both the passive layer resistance and the charge transfer resistance decreased with the increase in the potential.展开更多
Hydrogel electrolyte is especially suitable for solid-state Al-air batteries targeted for various portable applications, which may, however, lead to continuous Al corrosion during battery standby. To tackle this issue...Hydrogel electrolyte is especially suitable for solid-state Al-air batteries targeted for various portable applications, which may, however, lead to continuous Al corrosion during battery standby. To tackle this issue, an ethanol gel electrolyte is developed for Al-air battery for the first time in this work, by using KOH as solute and polyethylene oxide as gelling agent. The ethanol gel is found to effectively inhibit Al corrosion compared with the water gel counterpart, leading to stable Al storage. When assembled into an Al-air battery, the ethanol gel electrolyte achieves a much improved discharge lifetime and specific capacity, which are 5.3 and 4.1 times of the water gel electrolyte at 0.1 mA cm^(-2), respectively.By studying the gel properties, it is found that a lower ethanol purity can improve the battery power output, but at the price of decreased discharge efficiency. On the contrary, a higher polymer concentration will decrease the power output, but can bring extra benefit to the discharge efficiency. As for the gel thickness, a moderate value of 1 mm is preferred to balance the power output and energy efficiency. Finally, to cater the increasing market of flexible electronics, a flexible Al-air battery is developed by impregnating the ethanol gel into a paper substrate, which can function normally even under serious deformation or damage.展开更多
文摘The corrosion behavior of tantalum in tetraethyl ammonium chloride （TEA） ethanol solutions was investigated using potentiodynamic polarization, cyclic voltammetry, and impedance techniques along with scanning electron microscopy （SEM）. At the early stage of scanning, the current density in the cyclic voltammetry curves very slowly increased because of the presence of a thin oxide film on the electrode surface. Pitting corrosion then occurred as a result of the passivity breakdown caused by the aggressive attack of the Cl^- anions. SEM images showed the growth process of the pits on the electrode surface. The pitting potential decreased with the increase in TEA concentration but increased with the increase in water concentration. The apparent activation energy of the electrochemical reaction was 36 kJ/mol. The impedance spectra exhibited two time constants for all the potentials. Both the passive layer resistance and the charge transfer resistance decreased with the increase in the potential.
基金the SZSTI of Shenzhen Municipal Government (JCYJ20170818141758464)the CRCG grant of the University of Hong Kong (201910160008)。
文摘Hydrogel electrolyte is especially suitable for solid-state Al-air batteries targeted for various portable applications, which may, however, lead to continuous Al corrosion during battery standby. To tackle this issue, an ethanol gel electrolyte is developed for Al-air battery for the first time in this work, by using KOH as solute and polyethylene oxide as gelling agent. The ethanol gel is found to effectively inhibit Al corrosion compared with the water gel counterpart, leading to stable Al storage. When assembled into an Al-air battery, the ethanol gel electrolyte achieves a much improved discharge lifetime and specific capacity, which are 5.3 and 4.1 times of the water gel electrolyte at 0.1 mA cm^(-2), respectively.By studying the gel properties, it is found that a lower ethanol purity can improve the battery power output, but at the price of decreased discharge efficiency. On the contrary, a higher polymer concentration will decrease the power output, but can bring extra benefit to the discharge efficiency. As for the gel thickness, a moderate value of 1 mm is preferred to balance the power output and energy efficiency. Finally, to cater the increasing market of flexible electronics, a flexible Al-air battery is developed by impregnating the ethanol gel into a paper substrate, which can function normally even under serious deformation or damage.
