1. Eco-Friendly Photo-Thermal Deoxygenated
Graphite and Aluminum Supercapacitor Bank for
Space Satellite Application
Amanda Arst
Daniel Pearl Magnet High School
Van Nuys, California, United States

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SECTION PAGE #
TITLE PAGE 1
TABLE OF CONTENTS 2
ABSTRACT 4
INTRODUCTION 5
OBJECTIVES 8
METHODS AND PROCEDURES 9

3. 3
DISCUSSION 16
CONCLUSION 17
FUTURE APPLICATIONS 17
FUTURE RESEARCH 18
REFERENCES 19
PHOTOGRAPHS 20

4. 4
ABSTRACT
Objective or Goal:
Currently energy storage used in space satellite technology is crucial because there
must be accumulated energy to sustain payload operations during times when no sun is
illuminating photo voltaic arrays. Supercapacitors can be used to supplement storage
battery energy since it requires short 60 seconds charge times. The goal of this study is
to design and fabricate an eco-friendly photo-thermal deoxygenation graphite and
aluminum supercapacitor bank for space satellite application with the purpose of using
the device as 1.) an energy storage supply and 2.) a method of smoothing power
transients caused by changes in payload operation .
Materials and Methods:
I designed and fabricated a light weight, eco-friendly supercapacitor bank made with
six electrode pairs. Each electrode pair was made from graphite impregnated PET,
Celgard monolayer polypropylene separator membrane, aluminum current collector,
activated with absorbent gel sodium acetate (NaC₂H₃O₂) electrolyte. The sodium
acetate (99.9 %) was mixed with Xanthan gum and water (H2O). The positive electrode
was prepared using a buffer and photographic camera flash photo-thermal
deoxygenation process using a Nikon Speedlight SB 800. Connector tabs for the
positive electrode were made of copper tape secured with Kapton tape. A Goldstar DM
7333 digital multimeter was used to monitor the current and voltage, an LED light with a
100 ohm current limiting resistor was used to test the functional application of the
supercapacitor bank.
Results:
The functional operation of this device was tested by first measuring resistance of the
electrodes prior to activation, then after activation, charging the supercapacitor with a 9
volt battery. The experimental examination of this device showed 2.7 volts across the
Supercapacitor, 43 mV (millivolts) across the 100 ohm resistor, indicating 43mA
(milliamp) of current during discharge into the LED resistor circuit. The results showed
a maximum current in the series circuit of 1mA at the beginning of discharge and
0.2mA at 1.5 minutes.
Conclusion/Discussion:
The LED light turned on indicating the supercapacitor bank was indeed storing
energy. This device can be used as an initial phase for space satellite applications in
identifying the potential for energy storage and payload applications.

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INTRODUCTION:
Supercapacitors have been emerging as an important electrical
energy storage topic in the last few years. Currently energy storage used
in space satellite technology is crucial because there must be enough
accumulated energy to sustain payload operations during times when no
sun is illuminating photo voltaic solar arrays. Batteries used for space
satellite applications today, primarily use rechargeable Nickel Hydrogen
(NiH2) or Lithium-Ion (Li-Ion) battery cells.
The service life of a communication satellite is ~ 10 to 15 years. For
GEO stationary satellites, during equinox, discharge power is needed for
up to 72 minutes out of a 24-hour time period. Supercapacitors are
needed for their higher instantaneous power density, shorter charge times,
and lower watt -hour density relative to storage batteries. Supercapacitors
can be used to supplement storage battery energy and smoothing power
systems voltage transients. Both the classic battery and supercapacitors
may require the same 10 years life expectancy for satellites however, the
supercapacitor requires short 10 seconds charge times to support higher
watt density. Although supercapacitors disadvantage is its low volumetric
energy, it is longer lasting, light weight, safe and more environmentally

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friendly than batteries. Supercapacitors will be able to stabilize power
systems and their payloads, or act in conjunction with batteries.
Function Supercapacitor
Lithium-ion
(general)
Charge time
Cycle life
Cell voltage
Specific energy
(Wh/kg)
Specific power
(W/kg)
Service life (in
satellite)
1–10 seconds
1 million or 30,000h
2.3 to 2.75V
5 (typical)
Up to 10,000
10 to 15 years
10–60 minutes
500 and higher
3.6 to 3.7V
100–200
1,000 to 3,000
5 to 10 years
Table 1: Performance comparison between supercapacitor and Li-ion
(source: batteryuniversity.com)
Supercapacitors, also called Ultracapacitors or Electric Double Layer
Capacitors (EDLC) is made up of two electrodes (in this study- graphite and
aluminum) with an ion separator that is permeable to prevent the short
circuit of the device, and electrolyte ( sodium acetate) that will be able to
connect the electrodes. Usually batteries that are used are able to store
more energy than the Supercapacitor; however it takes a long time to
charge. Capacitors may be able to have a quick charge but it doesn’t hold

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on to the charge for a long time. Therefore this is where the Supercapacitor
comes in, the Supercapacitor is able to take the capability of the battery and
store a lot of energy for a greater length of time while at the same time
using the capabilities of the capacitor to have a quick charge. Below is the
Ragone chart which shows an assessment of the energy in the various
devices. The energy density is shown in Watt-hour Kilogram (W-h/kg) and
the power density is shown in the Watt Kilogram (W/kg).
Ragone chart showing energy density vs. power
density Source: instructables.com

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Energy Density is
calculated using the
following formula :
Power Density is
calculated using
the following
formula :
Where V is the voltage (V), I is the electric current
(A), t time (s) and m mass (kg)
OBJECTIVES:
The object of this research was to design and fabricate an eco-
friendly photo-thermal deoxygenation graphite (cathode) and aluminum
(anode) super-capacitor bank for space satellite application with the
purpose of using the device as 1.) An energy storage supply and 2.) A
method of smoothing power transients caused by changes in payload
operation (i.e. loads turning on and off).

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METHODS AND PROCEDURES
I designed and fabricated a light weight, environmentally safe
supercapacitor bank made with six electrode pairs. Each electrode pair,
was made from graphene impregnated PET (MG Chemicals 416-T PET
transparency film sheet, 11" length x 8-1/2" width), Celgard monolayer
polypropylene separator membrane, aluminum current collector, activated
with absorbent gel sodium acetate (NaC₂H₃O₂) electrolyte. The sodium
acetate (99.9 %) was mixed with Xanthan gum and water (H2O). The
positive electrode was prepared using a buffer and photographic camera
flash photo-thermal deoxygenation process using a Nikon Speedlight SB
800. I used 6 aluminum sheets (11cm X 4 cm) as the one piece negative
electrode and terminal with the 6 graphene PET substrate sheets (7 cm X
4 cm) as the positive terminal. Connector tabs for the positive electrode
were made of copper tape secured with copper and space qualified Kapton
tape. During the charge and discharge cycles I used a Goldstar DM 7333
digital multimeter to monitor the current and voltage, an LED light with a
100 ohm current limiting resistor was used to test the functional application
of the supercapacitor bank.

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12. 12

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.
Charge Cycle
Time
(Seconds) Voltage
0 0.71
30 2.4
60 2.4
90 2.48
120 2.55
150 2.6
180 2.57
240 2.6
300 2.6
0.71
2.4
2.4
2.48
2.55
2.6
2.57
2.6
2.6
0
0.5
1
1.5
2
2.5
3
0
30
60
90
120
150
180
240
300
Voltage
Time (Seconds)
Charge Voltage as A Function
of Time
Voltage

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Calculations based on data collected when testing
2.4
1.95
1.86
1.86
1.5
1.6
1.7
1.8
1.9
2
2.1
2.2
2.3
2.4
2.5
315
330
360
420
Voltage
Time (Seconds)
Charge Voltage as A Function of Time
Voltage Across
SuperCapacitor…
0.015
0.033
0.045
0
0.01
0.02
0.03
0.04
0.05
315
330
360
420
AmpereSeconds
Time (Seconds)
Integrated Ampere Seconds

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Discharge Into Series LED and 100 ohm resistor
Discharge
Cycle V=Ir; I=V/r
Time
(Secon
ds)
Elapas
ed
Time
Discha
rge
(Secon
ds)
Voltage
Across
SuperCapa
citor
(V)
No
te
1
Vr
(V)
Curr
ent
Note
2
(Vr/r)
(Amp
s)
Note 3
Amp
Capacit
y Out
(Amp_s
ec)
Ener
gy
Out
(Wse
c)
Capacita
nce
A_Sec/V
Farads
315 2.4
330 15 1.95 0.1 0.001 0.015
0.02
9
360 45 1.86
0.0
6
0.000
6 0.033
0.06
3
420 105 1.86
0.0
2
0.000
2 0.045
0.08
5 0.02 F

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DISCUSSION
The functional operation of this device was tested by first measuring
resistance of the electrodes prior to activation, then after activation and
charging the supercapacitor with a 9 volt battery. The experimental
examination of this device showed 2.7 volts across the Supercapacitor, 43
mv across the 100 ohm resistor indicating 43mA of current during
discharge into the LED resistor circuit. Charging and discharging this
supercapacitor bank did not show any degradation in the cell. The first sets
of tests were graphed for Charge time and Self Discharge time. The
second set of tests was performed 24 hours after activation. I charged the
battery with an 8.6 Volt source (9 volt battery) connected directly to the
supercapacitor terminals for 5 minutes. The voltage started at 0.7V prior to
connection. Periodic voltage measurements were taken on charge and
open circuit throughout. At the end of 5 minutes the open circuit voltage
was 2.6 V. Then the Supercapacitor was discharged into a series LED and
100 ohm circuit. Voltage measurements were taken across the resistor to
determine the current and supercapacitor to determine the total system
voltage under load. The results showed a maximum current in the series

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circuit of 1mA at the beginning of discharge and 0.2mA at 1.5 minutes. The
average capacity extracted was 15u-ampere-hours.
CONCLUSION:
In conclusion, this research provided a first step in the design and
fabrication of an eco-friendly photo-thermal deoxygenation graphene and
aluminum super-capacitor bank for space satellite application. After many
hours of researching, designing and redesigning this device I was finally
able to understand that additional work is needed to obtain the desired
supercapacitor properties. I was nevertheless able to store enough energy
to light the LED. The testing of this device showed that it is possible create
an energy storage device to supplement load needs such as payloads for
space satellite application. The inexpensive and simple materials that
were used in the construction of this supercapacitor bank can be
improved. Using sodium acetate gel electrolyte over more commonly used
electrolytes will be more environmentally safe over other toxic compounds
that are released into the air.
FUTURE APPLICATIONS

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Currently supercapacitors are generally considered for use on small
electronics such as phones, alarm clocks, audio devices and flashlights.
However, supercapacitor banks can be used in the future for large energy
storage devices such as hybrid cars, space robots, military vehicles and
buses. Also, if the supercapacitor bank is used in conjunction with battery
power it will help to increase the energy storage and make the systems
more reliable.
FUTURE RESEARCH:
Future research will involve looking into developing a larger
supercapacitor bank with lower ESR capable of storing more energy
efficiently. Additionally, utilization in a lab environment where it will be
possible to test the physical characterization of the supercapacitor bank
using a Scanning Electron Microscopy (SEM) will be beneficial. Also,
testing will be done to see if a modified device operates well under harsh
weather environment.
Furthermore, analysis can be performed on different separators and
electrolytes to uncover the most efficient and environmentally friendly
elements that can be used in building an eco-friendly photo-thermal
deoxygenation graphite and aluminum super-capacitor bank for space

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satellite application. Finally, additional electrode pairs, or redesign to
flatten the electrodes are needed to produce more capacity in the
supercapacitor bank and to lower the ESR and peak current capability.

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REFERENCES:
Conway, B. E., Electrochemical Supercapacitors Scientific
Fundamentals and Technological Applications, Kluwer Academic/
Plenum, New York, 1999, Chap.
Cheng, Yingwen, Hongbo Zhang, Songtao Lu, Chakrapani V.
Varanasi, and Jie Liu. "Nanoscale." Flexible Asymmetric
Supercapacitors with High Energy and High Power Density in
Aqueous Electrolytes - (RSC Publishing). The Royal Society of
Chemistry, 2013. Web. 21 Feb. 2015.
Engineering Shock. "Let's Learn about Super Capacitors! (A Practical
Guide to Super Capacitors)." Instructables.com. N.p., 2014. Web. 21
Feb. 2015.
Shimiz, T., & Underwood, C. (2009, August 5). Power Subsystem
Design for Micro-Satellites Using SuperCapacitor Energy Storage.
Retrieved February 22, 2015.
Zhao, J.P., Pei, S.F., Ren, W.C., Gao, L.B. & Cheng, H.M. Efficient
Preparation of Large-Area Graphene Oxide Sheets for Transparent
Conductive Films. Acs Nano 4, 5245-5252 (2010).

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PHOTOS
Making Graphite Electrodes with PET substrate sheets
Measuring Graphite Powder Cutting Graphite electrodes

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Testing the graphite electrode Graphite electrodes
Nikon Speedlight SB 800 for photo-thermal deoxygenation graphite
Measuring Separators for
Supercapacitors

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Separating aluminum and copper terminals with Kapton tape
Cutting Aluminum current collector Putting the separator between the electrodes
Building the supercapacitor Supercapacitor with aluminum and copper terminals

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Testing the supercapacitor voltage Soldering wire
Charging Supercapacitor bank - LED light Putting Supercapacitors into container-parallel
Adding Sodium Acetate electrolyte Setting up for 2
nd
testts

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2nd voltage tests