Download - Www.covalentassociates.com SBIR Grant No. DE-FG02-06ER84598 K. K. Tikhonov, W.A. Cataldo and V. R. Koch (P.I.) Covalent Associates, Inc. 10 State Street.

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SBIR Grant No. DE-FG02-06ER84598

K. K. Tikhonov, W.A. Cataldo and V. R. Koch (P.I.)

Covalent Associates, Inc.10 State Street

Woburn, MA 01801

Thermally Robust Capacitors for the Drilling Industry


Drilling Industry Market for Down Hole Power Sources

• Li/SOCl2 battery sales >$200M/year

• A Li/SOCl2:EDLC hybrid power source that provides pulse power from the EDLC would capture half of the market

• At present, 95% of this market requires power sources that operate between 100ºC and 150ºC; 5% requires performance between 150ºC and 225ºC


Phase I Objectives

• Synthesize, purify and electrochemically characterize a number of new IL electrolyte materials

• Evaluate the new electrolytes in EDLC coin cells and in wound AA-size cells (Redox Engineering) at temps ranging from 150ºC to 225ºC

Electrolyte Specific Conductance

0

10

20

30

40

50

60

70

80

0 50 100 150 200T (

oC)

Co

nd

uct

ivit

y (m

S/c

m)

IL2

1M TEABF4/PCIL1

IL3


EDLC Hardware


Redox EngineeringBonita Springs, FL

0

10

20

30

0 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000

cycle #

Ca

pa

cit

an

ce

(F/

g)

Coin Cells: 150oC at 1.75V

0

10

20

30

0 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000

cycle #

Ca

pa

cit

an

ce

(F/

g)

IL 1, 10 mA/cm2

IL 2, 10 mA/cm2


Self-discharge at 150oC

0.0

0.5

1.0

1.5

2.0

2.5

0 20 40 60 80 100 120 140 160

Time (min)

Vo

lta

ge

(V

)

fresh

after 20 cycles

after 600 cycles

2 hours, OCV


0

5

10

15

20

25

30

35

0 1000 2000 3000 4000 5000 6000cycle #

Ca

pa

cita

nce

(F

)Unoptimized Wound AA Cell

Performance at 150oC

IL 2


IL3 Cyclability to 2V at 225oC


0

5

10

15

20

0 5 10 15 20 25 30

cycle #

Ca

pa

cit

an

ce

(F

/g)

0.01

0.1

1

10

100

1000

10 100 1000 10000

Ragone Plot


EDLC current pulses: 10 to 250 mA/cm2

at 150ºC with IL2

Summary• The new ionic liquid electrolytes have been shown to be thermo-

chemically and electrochemically compatible with commercially available electrodes and cell packaging at elevated temperatures.

• EDLC cycle life (>103 cycles) and calendar life (>103 hr) are more than adequate for down hole applications.

• Safe and reliable high temp EDLCs can be manufactured and sold for less than either bobbin or wound Li/SOCl2 batteries.

• Phase I objectives have been met; Phase II will advance high temp EDLC technology by testing hermetically sealed wound capacitors down hole in a pulser tool.
