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Electric charging/discharging characteristics of super capacitor, using de-alloying and anodic oxidized Ti-Ni-Si amorphous alloy ribbons.

Fukuhara M, Sugawara K - Nanoscale Res Lett (2014)

Bottom Line: Charging/discharging behaviors of de-alloyed and anodic oxidized Ti-Ni-Si amorphous alloy ribbons were measured as a function of current between 10 pA and 100 mA, using galvanostatic charge/discharging method.In sharp contrast to conventional electric double layer capacitor (EDLC), discharging behaviors for voltage under constant currents of 1, 10 and 100 mA after 1.8 ks charging at 100 mA show parabolic decrease, demonstrating direct electric storage without solvents.The supercapacitors, devices that store electric charge on their amorphous TiO2-x surfaces that contain many 70-nm sized cavities, show the Ragone plot which locates at lower energy density region near the 2nd cells, and RC constant of 800 s (at 1 mHz), which is 157,000 times larger than that (5 ms) in EDLC.

View Article: PubMed Central - HTML - PubMed

Affiliation: New Industry Creation Hatchery Center, Tohoku University, 3-4-1, Sakuragi, Tagajyo, Miyagi 985-8589, Japan ; Fracture and Reliability Research Institute, Tohoku University, Sendai 980-8579, Japan ; Green Device Laboratory, Institute for Nanoscience & Nanotechnology, Waseda University, Shinjuku, Tokyo 162-0041, Japan.

ABSTRACT
Charging/discharging behaviors of de-alloyed and anodic oxidized Ti-Ni-Si amorphous alloy ribbons were measured as a function of current between 10 pA and 100 mA, using galvanostatic charge/discharging method. In sharp contrast to conventional electric double layer capacitor (EDLC), discharging behaviors for voltage under constant currents of 1, 10 and 100 mA after 1.8 ks charging at 100 mA show parabolic decrease, demonstrating direct electric storage without solvents. The supercapacitors, devices that store electric charge on their amorphous TiO2-x surfaces that contain many 70-nm sized cavities, show the Ragone plot which locates at lower energy density region near the 2nd cells, and RC constant of 800 s (at 1 mHz), which is 157,000 times larger than that (5 ms) in EDLC.

No MeSH data available.


Related in: MedlinePlus

Frequency dependence of capacitance (a) and RC constant (b). For de-alloyed and anodic oxidized Ti-Ni-Si and de-alloyed Si-Al specimens in an input voltage of 10 V at room temperature.
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Figure 5: Frequency dependence of capacitance (a) and RC constant (b). For de-alloyed and anodic oxidized Ti-Ni-Si and de-alloyed Si-Al specimens in an input voltage of 10 V at room temperature.

Mentions: Capacitance as a function of frequency at room temperature is presented logarithmically in Figure 5a, along with those of the de-alloyed Si-20at%Al specimen [11]. Frequency dependent capacitances decreased parabolic from around 0.1 mF (0.54 F/cm3) to around 1.3 pF (53 μF/cm3) with increasing frequency and saturated from 0.1 to 0.4 nF in frequency region from 1 kHz to 1 MHz. The saturated values of the former are 30 times larger than those of the latter. This difference would be derived from higher absorbed electron density of the former, accessible to electron trapping. Here it should be noted that charging/discharging of electrochemical cells occurs at lower frequency regions on the whole interfaces in pores of electrodes, but does not occur at higher frequency ones in interior parts of pores [21]. Hence, by analogy we infer that that the de-alloyed and anodic oxidized Ti-Ni-Si material, which shows large frequency dependence on capacitance independent of temperature, is an assembly of canyons with the deepest recess. The whole behavior in Figure 5a implies ac current momentary (below 0.1 s) charging/discharging, with the observed decrease in capacitance come from dielectric dispersion by interfacial polarization. These results would be associated with electron storage in amorphous TiO2-x coated solid cell without solvents. Furthermore, we can store electricity in ac current using a rectifier, if we could be taken a figure up three places over capacitance at higher frequencies.


Electric charging/discharging characteristics of super capacitor, using de-alloying and anodic oxidized Ti-Ni-Si amorphous alloy ribbons.

Fukuhara M, Sugawara K - Nanoscale Res Lett (2014)

Frequency dependence of capacitance (a) and RC constant (b). For de-alloyed and anodic oxidized Ti-Ni-Si and de-alloyed Si-Al specimens in an input voltage of 10 V at room temperature.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4061119&req=5

Figure 5: Frequency dependence of capacitance (a) and RC constant (b). For de-alloyed and anodic oxidized Ti-Ni-Si and de-alloyed Si-Al specimens in an input voltage of 10 V at room temperature.
Mentions: Capacitance as a function of frequency at room temperature is presented logarithmically in Figure 5a, along with those of the de-alloyed Si-20at%Al specimen [11]. Frequency dependent capacitances decreased parabolic from around 0.1 mF (0.54 F/cm3) to around 1.3 pF (53 μF/cm3) with increasing frequency and saturated from 0.1 to 0.4 nF in frequency region from 1 kHz to 1 MHz. The saturated values of the former are 30 times larger than those of the latter. This difference would be derived from higher absorbed electron density of the former, accessible to electron trapping. Here it should be noted that charging/discharging of electrochemical cells occurs at lower frequency regions on the whole interfaces in pores of electrodes, but does not occur at higher frequency ones in interior parts of pores [21]. Hence, by analogy we infer that that the de-alloyed and anodic oxidized Ti-Ni-Si material, which shows large frequency dependence on capacitance independent of temperature, is an assembly of canyons with the deepest recess. The whole behavior in Figure 5a implies ac current momentary (below 0.1 s) charging/discharging, with the observed decrease in capacitance come from dielectric dispersion by interfacial polarization. These results would be associated with electron storage in amorphous TiO2-x coated solid cell without solvents. Furthermore, we can store electricity in ac current using a rectifier, if we could be taken a figure up three places over capacitance at higher frequencies.

Bottom Line: Charging/discharging behaviors of de-alloyed and anodic oxidized Ti-Ni-Si amorphous alloy ribbons were measured as a function of current between 10 pA and 100 mA, using galvanostatic charge/discharging method.In sharp contrast to conventional electric double layer capacitor (EDLC), discharging behaviors for voltage under constant currents of 1, 10 and 100 mA after 1.8 ks charging at 100 mA show parabolic decrease, demonstrating direct electric storage without solvents.The supercapacitors, devices that store electric charge on their amorphous TiO2-x surfaces that contain many 70-nm sized cavities, show the Ragone plot which locates at lower energy density region near the 2nd cells, and RC constant of 800 s (at 1 mHz), which is 157,000 times larger than that (5 ms) in EDLC.

View Article: PubMed Central - HTML - PubMed

Affiliation: New Industry Creation Hatchery Center, Tohoku University, 3-4-1, Sakuragi, Tagajyo, Miyagi 985-8589, Japan ; Fracture and Reliability Research Institute, Tohoku University, Sendai 980-8579, Japan ; Green Device Laboratory, Institute for Nanoscience & Nanotechnology, Waseda University, Shinjuku, Tokyo 162-0041, Japan.

ABSTRACT
Charging/discharging behaviors of de-alloyed and anodic oxidized Ti-Ni-Si amorphous alloy ribbons were measured as a function of current between 10 pA and 100 mA, using galvanostatic charge/discharging method. In sharp contrast to conventional electric double layer capacitor (EDLC), discharging behaviors for voltage under constant currents of 1, 10 and 100 mA after 1.8 ks charging at 100 mA show parabolic decrease, demonstrating direct electric storage without solvents. The supercapacitors, devices that store electric charge on their amorphous TiO2-x surfaces that contain many 70-nm sized cavities, show the Ragone plot which locates at lower energy density region near the 2nd cells, and RC constant of 800 s (at 1 mHz), which is 157,000 times larger than that (5 ms) in EDLC.

No MeSH data available.


Related in: MedlinePlus