<s>
An	O
organic	B-Algorithm
radical	I-Algorithm
battery	I-Algorithm
(	O
ORB	O
)	O
is	O
a	O
type	O
of	O
battery	O
first	O
developed	O
in	O
2005	O
.	O
</s>
<s>
For	O
example	O
,	O
the	O
nitroxide	O
radical	O
in	O
(	O
2	O
,	O
2	O
,	O
6	O
,	O
6-tetramethylpiperidin-1-yl	O
)	O
oxyl	O
(	O
TEMPO	B-Application
)	O
,	O
the	O
most	O
common	O
subunit	O
used	O
in	O
ORBs	O
,	O
is	O
a	O
stable	O
oxygen-centered	O
molecular	O
radical	O
.	O
</s>
<s>
TEMPO	B-Application
radicals	O
can	O
be	O
attached	O
to	O
polymer	O
backbones	O
to	O
form	O
poly(2,2,6,6-tetramethyl- piperidenyloxyl-4-yl methacrylate )	O
(	O
PTMA	O
)	O
.	O
</s>
<s>
Organic	B-Algorithm
radical	I-Algorithm
batteries	I-Algorithm
were	O
first	O
researched	O
and	O
developed	O
by	O
NEC	O
in	O
2005	O
with	O
the	O
intent	O
of	O
being	O
widely	O
used	O
to	O
power	O
tiny	O
gadgets	O
in	O
the	O
near	O
future	O
.	O
</s>
<s>
Since	O
the	O
beginning	O
of	O
development	O
,	O
smart	O
cards	O
and	O
RFID	B-Application
tags	I-Application
were	O
the	O
main	O
targets	O
for	O
ORB	O
usage	O
.	O
</s>
<s>
Given	O
the	O
fast	O
redox	B-Operating_System
chemistry	O
of	O
nitroxide	O
radicals	O
,	O
ORBs	O
have	O
been	O
shown	O
useful	O
in	O
keeping	O
a	O
computer	O
running	O
momentarily	O
following	O
a	O
power	O
outage	O
.	O
</s>
<s>
Radical	O
polymer	O
batteries	O
rely	O
on	O
a	O
redox	B-Operating_System
reaction	I-Operating_System
of	O
an	O
organic	O
radical	O
to	O
generate	O
an	O
electrochemical	O
potential	O
.	O
</s>
<s>
The	O
most	O
studied	O
example	O
of	O
such	O
an	O
organic	O
radical	O
redox	B-Operating_System
reaction	I-Operating_System
is	O
that	O
of	O
nitroxide	O
radicals	O
,	O
such	O
as	O
the	O
one	O
found	O
on	O
a	O
molecule	O
called	O
(	O
2	O
,	O
2	O
,	O
6	O
,	O
6-Tetramethylpiperidin-1-yl	O
)	O
oxyl	O
,	O
also	O
known	O
as	O
TEMPO	B-Application
.	O
</s>
<s>
The	O
positive	O
electrode	O
uses	O
the	O
nitroxide	O
-	O
oxammonium	O
cation	O
redox	B-Operating_System
pair	O
to	O
create	O
an	O
electrochemical	O
potential	O
,	O
i.e.	O
</s>
<s>
The	O
redox	B-Operating_System
potentials	O
for	O
nitroxide	O
show	O
some	O
variation	O
and	O
for	O
the	O
TEMPO	B-Application
nitroxide	O
for	O
this	O
redox	B-Operating_System
pair	O
has	O
an	O
oxidation	O
potential	O
of	O
+	O
0.87	O
V	O
.	O
The	O
positive	O
electrode	O
often	O
takes	O
the	O
shape	O
of	O
a	O
gel	O
made	O
of	O
organic	O
radical	O
solids	O
and	O
graphite	B-Application
,	O
permeated	O
with	O
electrolytes	O
.	O
</s>
<s>
Graphite	B-Application
is	O
mixed	O
with	O
the	O
polymer	O
to	O
increase	O
the	O
conductivity	O
.	O
</s>
<s>
The	O
negative	O
electrode	O
uses	O
the	O
nitroxide	O
-	O
hydroxylamine	O
anion	O
redox	B-Operating_System
pair	O
to	O
create	O
an	O
electrochemical	O
potential	O
,	O
i.e.	O
</s>
<s>
This	O
half-reaction	O
has	O
an	O
oxidation	O
potential	O
of	O
-0.11	O
V	O
.	O
Since	O
this	O
half-reaction	O
is	O
not	O
readily	O
reversible	O
as	O
the	O
half-reaction	O
at	O
the	O
positive	O
electrode	O
,	O
several	O
research	O
groups	O
have	O
steered	O
away	O
from	O
using	O
pure	O
organic	B-Algorithm
radical	I-Algorithm
batteries	I-Algorithm
and	O
instead	O
use	O
metal/ORB	O
hybrid	O
batteries	O
usually	O
consist	O
of	O
a	O
radical	O
polymer	O
cathode	O
and	O
the	O
same	O
anode	O
found	O
in	O
rechargeable	O
Li-ion	O
batteries	O
.	O
</s>
<s>
Much	O
like	O
a	O
traditional	O
battery	O
such	O
as	O
a	O
Li-ion	O
battery	O
,	O
an	O
organic	B-Algorithm
radical	I-Algorithm
battery	I-Algorithm
consists	O
of	O
a	O
cathode	O
and	O
an	O
anode	O
that	O
are	O
separated	O
by	O
a	O
porous	O
film	O
and	O
submerged	O
in	O
an	O
electrolyte	O
.	O
</s>
<s>
In	O
a	O
pure	O
organic	B-Algorithm
radical	I-Algorithm
battery	I-Algorithm
,	O
both	O
terminals	O
are	O
made	O
of	O
organic	O
radical	O
polymers	O
(	O
a	O
p-type	O
and	O
an	O
n-type	O
polymer	O
)	O
,	O
while	O
a	O
metal/ORB	O
hybrid	O
battery	O
usually	O
has	O
a	O
radical	O
polymer	O
cathode	O
and	O
a	O
Li-ion/graphite	O
anode	O
.	O
</s>
<s>
Several	O
synthetic	O
approaches	O
have	O
been	O
utilized	O
in	O
the	O
synthesis	O
of	O
polyradical	O
species	O
for	O
use	O
in	O
organic	B-Algorithm
radical	I-Algorithm
batteries	I-Algorithm
.	O
</s>
<s>
The	O
decreased	O
number	O
of	O
nitroxide	O
groups	O
negatively	O
impacts	O
the	O
charge	O
capacity	O
of	O
the	O
polymer	O
and	O
limits	O
its	O
efficacy	O
in	O
organic	B-Algorithm
radical	I-Algorithm
batteries	I-Algorithm
.	O
</s>
<s>
Not	O
only	O
are	O
there	O
fewer	O
nitroxide	O
groups	O
present	O
,	O
but	O
also	O
side	O
reactions	O
between	O
non-oxidized	O
groups	O
and	O
oxammonium	O
cations	O
diminishes	O
the	O
redox	B-Operating_System
reversibility	O
of	O
the	O
compound	O
.	O
</s>
<s>
Rhodium-catalyzed	O
polymerization	O
of	O
TEMPO-bearing	O
monomers	O
avoids	O
some	O
of	O
the	O
challenges	O
free-radical	O
polymerization	O
poses	O
because	O
an	O
oxidation	O
step	O
to	O
generate	O
the	O
radical	O
is	O
not	O
needed	O
.	O
</s>
<s>
The	O
structure	O
of	O
(	O
2	O
,	O
2	O
,	O
6	O
,	O
6-Tetramethylpiperidine-1-yl	O
)	O
oxyl	O
or	O
TEMPO	B-Application
is	O
shown	O
below	O
.	O
</s>
<s>
The	O
following	O
monomers	O
(	O
1-3	O
)	O
can	O
be	O
synthesized	O
by	O
condensation	O
reaction	O
between	O
carboxyl	O
groups	O
with	O
the	O
amino	O
or	O
hydroxyl	O
group	O
of	O
acetylene	O
derivatives	O
and	O
various	O
TEMPO	B-Application
derivatives	O
.	O
</s>
<s>
Rhodium	O
catalyzed	O
synthesis	O
of	O
TEMPO	B-Application
containing	O
polymers	O
has	O
been	O
performed	O
with	O
high	O
quantitative	O
yield	O
.	O
</s>
<s>
Preparation	O
of	O
the	O
monomer	O
,	O
4-methacryloxyloxy-TEMPO	O
can	O
be	O
accomplished	O
by	O
acylation	O
of	O
4-hydroxy-TEMPO	O
with	O
methacryloyl	O
chloride	O
.	O
</s>
<s>
Organic	B-Algorithm
radical	I-Algorithm
batteries	I-Algorithm
are	O
much	O
more	O
environmentally	O
friendly	O
than	O
Li-ion	O
batteries	O
because	O
ORBs	O
do	O
not	O
contain	O
any	O
metals	O
that	O
pose	O
the	O
problem	O
of	O
proper	O
disposal	O
.	O
</s>
<s>
This	O
disadvantage	O
arises	O
because	O
the	O
redox	B-Operating_System
reaction	I-Operating_System
of	O
the	O
negative	O
electrode	O
is	O
not	O
fully	O
reversible	O
.	O
</s>
