Capacitors: Energy Storage and Conversion

Capacitors: Energy Storage and Conversion

Steven C. Tidrow

Kazuo Inamori School of Engineering Alfred University

Alfred, NY 14802

Comparison of Energy Storage Technologies

DOI: 10.1098/rsta.2010.0113

Comparison of Energy Storage Technologies

0 50 100 150 200 250 300 350 400 450 500 550 100

10000 1000000 1E8 1E10 1E12

x=0 x=0.010 x=0.025 x=0.050

Resistivity (.m)

Temperature (^oC)

Enhancing Energy Storage and

Enabling Capacitive Energy Conversion

Maximum capacitor energy density:

𝐸

𝐴𝑑 _𝑚𝑎𝑥 = 𝜺_𝒓𝜺_𝟎

𝟐 𝜷 ^𝟐

Material breakdown strength: 𝜷 = 𝑽_𝒎𝒂𝒙 𝒅_𝒎𝒊𝒏 Self-discharge Time Constant: 𝑅𝐶 = 𝝆_𝒓𝜺_𝒓𝜺_𝟎

Breakdown Strength

Ba(Ga_y-Ta_y)Ti_1-2yO₃: 5 to 10 MV/m BaTiO₃: 1 MV/m

BaTiO₃

Through dilute dipole engineering

(Capacitor)

Thermoelectric Energy Conversion Gain and Efficiency

∆𝑊

𝑊₀

=

^{𝑊𝑓−𝑊0}

𝑊₀

= 𝜀

_𝑟𝐶 ^{𝜀𝑟𝐶−𝜀𝑟𝐻}

𝜀_𝑟𝐻𝜀_𝑟𝐶

=

^{𝜀𝑟𝐶−𝜀𝑟𝐻}

𝜀_𝑟𝐻

≈ 𝟒

The device efficiency is:

𝜀

_𝑒𝑓𝑓

= 1 − 𝑄

_𝐶

𝑄

_𝐻

= 1 − 𝜀

_{𝑟 ℎ𝑜𝑡}

𝜀

_{𝑟(𝑐𝑜𝑙𝑑)}

 0.80

and is significantly higher efficiency than thermoelectric Peltier, Thomson, Seeback effect

Factor of energy increase between capacitive states: