SUPERCAPACITORS OF HIGH

POWER AND ENERGY DENSITY

N. Stryzhakova, S. Zelinsky, and Y. Maletin

nstryzhakova@yunasko.com

Institute for Sorption and

Problems of Endoecology,

National Academy of

Science of Ukraine

Yunasko-Ukraine

Low internal resistance, Rin

- key advantage of SC devices in various applications

Heat generation = ʃI2Rint

(low heat generation implies simple design and safety)

Efficiency = RLoad/(RLoad + Rin)

(high efficiency is important for KERS and many other applications)

Power output ~ 1/ Rin

(high power density allows to meet customer requirements with less mass)

Also MASS and COST reduction!

Quick response (low RC-constant)

(is important for grid frequency regulation)

Working voltageElectrochemical

“window”

Capacitance

Pore structure

Ion size

ResistanceConductivity,

Ion mobility

Leakage currentSurface chemistryElectrochemically

active impurities

SupercapacitorElectrode material Electrolyte

rAl-C ~ 0.01rC ~ 0.07

Thus:relectrolyte ~ 0.9

“pore resistance” ~ 0.7

SC resistivity (in W.cm2)

total ~ 1.0

Though: relectrolyte in bulk ~ 0.2

Abstract

As pure “physical” devices, which do not involve any chemical or electrochemical transformations, any charge or mass transfer through the

electrode-electrolyte interface, SC’s must demonstrate much faster charge/discharge operations and longer cycle life than any “chemical”

batteries. Given this, SC devices can provide the key to a number of efficient power solutions that are mainly related with various backup

systems to compensate short-term voltage surges or drops or with load leveling the batteries in various combined power sources. Low

internal resistance can be one of key advantages of SC’s over all other types of energy storage devices.

Correlation of Fc+ diffusion

coefficients in-pores with

SC resistance

YUNASKO carbon-carbon EDLC performance (rated voltage 2.7V)

16 V, 200 F

ESR (dc) 1.0 mWmass 2.5 kg

equipped with voltage balancing

system and temperature sensor

Contributions to

total resistance

in bulk solution :

Deff = 10.1×10-10 m2/s

CV curves:

3-electrode cell (A), SC prototype (B)electrolyte: 1.3M TEMA BF4 in acetonitrile;

scan rate: 10 mV/s

A

B

Financial support from NAS Ukraine-STCU Project # 5500 is very much acknowledged

Charge accumulated by positive

and negative electrodes