Effects of temperatures and carbon dioxide nanobubbles on superior electric storage for anodically oxidized films of AlY10 amorphous alloy

Mikio Fukuhara,Tomoyuki Suwa,Kazuhisa Sato,Tomoyuki Kuroda,Masahiko Nishijima,Toshiyuki Hashida,Fumihiko Hasegawa,Masayoshi Takahashi,K Konno

doi:10.1063/1.5102082

Abstract

The effects of temperature and nanometer-sized bubbles (NBs) on a superior electric storage capacitor for anodically oxidized films of AlY10 amorphous alloys were determined at temperatures ranging from 275 to 298 K in 0.4 M H2SO4 solutions with NBs of ozone, oxygen, and carbon dioxide. The AAO specimen obtained by solution with carbon dioxide NBs at 278 K showed longer discharging time. The discharging time increases with increasing charging time and then saturates after around 70 s. The increment in temperature makes the structure from simple series capacitor with large capacitance to simple parallel capacitor with lower capacitance and larger resistance. The stability of NBs in water could be explained by enclosure in protonated polyhedral water clusters. The collapse of clusters with oxygen NBs result in the formation of OH− radicals and its resulting elution of Al, while carbon oxide NBs prevent the formation of OH− radicals, promoting sluggish oxidation that is required for the formation of AlO6 clusters.

Highlights

Storage of electrical energy is currently attracting a great deal of interest in the field of physics.1–6 A significant amount of attention has been given to power source devices such as batteries and fuel cells
To investigate the effects of nanometer-sized bubbles (NBs) on the anodic oxidation of amorphous alloys, we studied the oxidation behaviors for the alloys in four types of 0.4 M H2SO4 solutions: pure water and water solutions with oxygen (9.78 mg/l), ozone (2 mg/l) and carbon dioxide (50 mg/l) NBs
The charging and discharging behaviors under a constant current at 1 nA after charging at 10 V for 50 s at a direct current (DC) of 1 mA is shown in Fig. 1(b), indicating long and short discharging times for carbon dioxide and oxygen NBWs solutions, respectively, compared with pure water used in the previous papers

Summary

Introduction

Storage of electrical energy is currently attracting a great deal of interest in the field of physics. A significant amount of attention has been given to power source devices such as batteries and fuel cells. The fractal structure of an EDLC is composed of a distributed constant equivalent circuit of active carbon (R) and electrolyte (C). We found that amorphous titanium-oxides (golden, a-TiO2-x, ATO) and aluminumoxides (blackish, a–Al2O3-y, AAO), showing an RC constant larger than EDLC and switching effect of positive and negative electricity from the atmosphere, respectively, can be regarded as a superior electric storage device with nanometer-sized uneven surfaces.. We can apply rechargeable dry supercapacitors in place of practical Li ions. We termed this device a “dry” electric distributed constant capacitor (EDCC). Since the electric capacitance of these amorphous surfaces increases proportionally to the negative sixth power of the convex diameter up to 7 mF/cm, we must investigate effective method on fabrication of AAO with uneven surfaces below

Results

Discussion

Conclusion