<s>
A	O
sugar	B-Algorithm
battery	I-Algorithm
is	O
an	O
emerging	O
type	O
of	O
biobattery	O
that	O
is	O
fueled	O
by	O
maltodextrin	O
and	O
facilitated	O
by	O
the	O
enzymatic	O
catalysts	O
.	O
</s>
<s>
The	O
sugar	B-Algorithm
battery	I-Algorithm
generates	O
electric	O
current	O
by	O
the	O
oxidation	B-Operating_System
of	O
the	O
glucose	O
unit	O
of	O
maltodextrin	O
.	O
</s>
<s>
The	O
oxidation	B-Operating_System
of	O
the	O
organic	O
compound	O
produces	O
carbon	O
dioxide	O
and	O
electrical	O
current	O
.	O
</s>
<s>
The	O
experimental	O
results	O
have	O
shown	O
that	O
the	O
sugar	B-Algorithm
battery	I-Algorithm
of	O
the	O
same	O
mass	O
can	O
store	O
at	O
least	O
two	O
times	O
,	O
up	O
to	O
ten	O
times	O
electrical	O
energy	O
than	O
the	O
traditional	O
lithium-ion	O
battery	O
can	O
.	O
</s>
<s>
The	O
sugar	B-Algorithm
battery	I-Algorithm
is	O
expected	O
to	O
be	O
the	O
next	O
general	O
type	O
of	O
mobile	O
electric	O
power	O
source	O
and	O
the	O
possible	O
power	O
source	O
for	O
electric	O
cars	O
.	O
</s>
<s>
But	O
the	O
sugar	B-Algorithm
battery	I-Algorithm
's	O
output	O
voltage( 	O
0.5V	O
)	O
is	O
lower	O
than	O
that	O
of	O
the	O
lithium-ion	O
battery	O
(	O
3.6V	O
)	O
,	O
which	O
causes	O
its	O
electric	O
power	O
(	O
the	O
rate	O
of	O
electrical	O
energy	O
transfer	O
)	O
to	O
be	O
low	O
.	O
</s>
<s>
Sony	O
,	O
a	O
Japanese	O
corporation	O
,	O
first	O
published	O
the	O
theory	O
of	O
sugar	B-Algorithm
battery	I-Algorithm
in	O
2007	O
.	O
</s>
<s>
Sony	O
,	O
a	O
Japanese	O
corporation	O
,	O
first	O
published	O
the	O
theory	O
of	O
sugar	B-Algorithm
battery	I-Algorithm
in	O
2007	O
.	O
</s>
<s>
This	O
type	O
of	O
sugar	B-Algorithm
battery	I-Algorithm
is	O
air-breathing	O
and	O
utilizes	O
the	O
oxygen	O
as	O
the	O
oxidizing	O
agent	O
.	O
</s>
<s>
Then	O
the	O
company	O
shifted	O
its	O
researching	O
direction	O
in	O
2012	O
to	O
the	O
paper	B-Algorithm
battery	I-Algorithm
,	O
which	O
uses	O
paper	O
as	O
fuel	O
.	O
</s>
<s>
Percival	O
Zhang	O
at	O
Virginia	O
Tech	O
started	O
the	O
project	O
of	O
the	O
sugar	B-Algorithm
battery	I-Algorithm
in	O
2009	O
.	O
</s>
<s>
In	O
2014	O
,	O
they	O
published	O
their	O
research	O
on	O
the	O
sugar	B-Algorithm
battery	I-Algorithm
that	O
utilizes	O
enzymes	O
in	O
oxidization	O
.	O
</s>
<s>
This	O
type	O
of	O
sugar	B-Algorithm
battery	I-Algorithm
reached	O
a	O
high	O
energy	O
density	O
.	O
</s>
<s>
The	O
sugar	B-Algorithm
battery	I-Algorithm
was	O
expected	O
to	O
be	O
realized	O
in	O
an	O
application	O
in	O
3	O
years	O
.	O
</s>
<s>
Since	O
then	O
,	O
Virginia	O
Tech	O
stopped	O
publishing	O
the	O
result	O
of	O
the	O
sugar	B-Algorithm
battery	I-Algorithm
study	O
.	O
</s>
<s>
Since	O
2014	O
,	O
Several	O
Chinese	O
universities	O
,	O
including	O
Zhejiang	O
University	O
and	O
Tianjin	O
University	O
,	O
started	O
working	O
on	O
researches	O
on	O
the	O
sugar	B-Algorithm
battery	I-Algorithm
.	O
</s>
<s>
Compared	O
to	O
the	O
currently	O
widely	O
used	O
lithium-ion	O
battery	O
,	O
the	O
sugar	B-Algorithm
battery	I-Algorithm
has	O
potential	O
benefits	O
in	O
many	O
aspects	O
.	O
</s>
<s>
Compared	O
to	O
the	O
traditional	O
lithium-ion	O
battery	O
,	O
sugar	B-Algorithm
battery	I-Algorithm
does	O
not	O
require	O
toxic	O
metals	O
in	O
manufacturing	O
and	O
releases	O
only	O
carbon	O
dioxide	O
gases	O
.	O
</s>
<s>
The	O
production	O
of	O
the	O
standard	O
lithium-ion	O
battery	O
would	O
require	O
several	O
metals	O
,	O
including	O
but	O
not	O
limited	O
to	O
lead	O
(	O
Pd	O
)	O
,	O
Cadmium	O
(	O
Cd	O
)	O
,	O
and	O
Chromium	B-Language
(	O
Cr	O
)	O
.	O
</s>
<s>
The	O
primary	O
fuel	O
of	O
the	O
sugar	B-Algorithm
battery	I-Algorithm
,	O
maltodextrin	O
,	O
can	O
be	O
enzymatically	O
derived	O
from	O
any	O
starch	O
,	O
such	O
as	O
corn	O
and	O
wheat	O
.	O
</s>
<s>
The	O
products	O
of	O
oxidation	B-Operating_System
reaction	I-Operating_System
inside	O
the	O
sugar	B-Algorithm
battery	I-Algorithm
are	O
mainly	O
water	O
,	O
carbon	O
dioxide	O
,	O
and	O
recyclable	O
adenosine	O
triphosphate	O
(	O
ATP	O
)	O
.	O
</s>
<s>
The	O
carbon	O
dioxide	O
produced	O
by	O
the	O
sugar	B-Algorithm
battery	I-Algorithm
does	O
not	O
contribute	O
to	O
the	O
crisis	O
of	O
greenhouse	O
gas	O
,	O
because	O
the	O
sugar	B-Algorithm
battery	I-Algorithm
uses	O
bio-fuel	O
that	O
is	O
carbon-neutral	O
.	O
</s>
<s>
The	O
complete	O
oxidation	B-Operating_System
reaction	I-Operating_System
of	O
unit	O
glucose	O
in	O
15%	O
maltodextrin	O
solution	O
enables	O
the	O
sugar	B-Algorithm
battery	I-Algorithm
to	O
have	O
an	O
energy	O
density	O
of	O
596	O
Ah	O
kg−1	O
,	O
which	O
is	O
over	O
twice	O
as	O
high	O
as	O
that	O
of	O
the	O
widely	O
used	O
lithium-ion	O
battery( 	O
~	O
270	O
Ah	O
kg−1	O
)	O
.	O
</s>
<s>
As	O
a	O
newly	O
invented	O
idea	O
,	O
the	O
sugar	B-Algorithm
battery	I-Algorithm
is	O
not	O
well	O
developed	O
yet	O
.	O
</s>
<s>
Though	O
the	O
output	O
voltage	O
of	O
sugar	B-Algorithm
battery	I-Algorithm
(	O
0.5V	O
)	O
exceeds	O
that	O
of	O
former	O
enzymatic	O
fuel	O
batteries	O
by	O
the	O
use	O
of	O
various	O
enzymatic	O
catalysts	O
,	O
it	O
is	O
still	O
much	O
lower	O
than	O
that	O
of	O
the	O
commonly	O
used	O
lithium-ion	O
battery	O
(	O
3.6V	O
)	O
.	O
</s>
<s>
In	O
application	O
,	O
it	O
means	O
that	O
the	O
sugar	B-Algorithm
battery	I-Algorithm
takes	O
more	O
time	O
to	O
charge	O
the	O
appliance	O
than	O
the	O
lithium-ion	O
battery	O
does	O
.	O
</s>
<s>
The	O
production	O
of	O
the	O
fuel	O
of	O
the	O
sugar	B-Algorithm
battery	I-Algorithm
and	O
the	O
reaction	O
inside	O
the	O
sugar	B-Algorithm
battery	I-Algorithm
require	O
water	O
to	O
complete	O
.	O
</s>
<s>
The	O
design	O
of	O
the	O
sugar	B-Algorithm
battery	I-Algorithm
is	O
based	O
on	O
the	O
theory	O
of	O
the	O
primary	B-Algorithm
cell	I-Algorithm
.	O
</s>
<s>
The	O
main	O
components	O
of	O
a	O
sugar	B-Algorithm
battery	I-Algorithm
are	O
an	O
anode	O
,	O
a	O
cathode	O
,	O
a	O
membrane	O
,	O
and	O
a	O
synthetic	O
pathway	O
.	O
</s>
<s>
The	O
oxidation	B-Operating_System
reaction	I-Operating_System
happens	O
in	O
the	O
anode	O
side	O
where	O
the	O
fuel	O
,	O
maltodextrin	O
,	O
is	O
oxidized	O
.	O
</s>
<s>
The	O
redox	B-Operating_System
reaction	I-Operating_System
that	O
produces	O
the	O
electrical	O
current	O
happens	O
in	O
the	O
synthetic	O
pathway	O
,	O
where	O
13	O
enzymes	O
,	O
such	O
as	O
glucose	O
6-phosphate	O
and	O
phosphoglucomutase	O
,	O
act	O
as	O
catalysts	O
(	O
the	O
substance	O
that	O
is	O
both	O
reactant	O
and	O
product	O
)	O
.	O
</s>
<s>
The	O
fuel	O
,	O
maltodextrin	O
,	O
is	O
divided	O
from	O
polymer	B-Language
to	O
monomer	O
and	O
then	O
oxidized	O
into	O
carbon	O
dioxide	O
and	O
hydrogen	O
ions	O
during	O
four	O
reactions	O
.	O
</s>
<s>
The	O
synthetic	O
pathway	O
is	O
composed	O
of	O
13	O
enzymes	O
to	O
ensure	O
the	O
redox	B-Operating_System
reaction	I-Operating_System
goes	O
into	O
completion	O
(	O
that	O
is	O
,	O
24	O
electrons	O
produced	O
per	O
glucose	O
unit	O
)	O
.	O
</s>
<s>
Theoretically	O
,	O
one	O
maltodextrin	O
's	O
glucose	O
unit	O
(	O
C6H10O5	O
)	O
generates	O
24	O
electrons	O
,	O
which	O
makes	O
the	O
sugar	B-Algorithm
battery	I-Algorithm
's	O
maximum	O
current	O
density	O
35%	O
higher	O
than	O
the	O
maximum	O
current	O
density	O
of	O
a	O
similar	O
system	O
based	O
on	O
2	O
dehydrogenases	O
.	O
</s>
<s>
Practically	O
,	O
the	O
researchers	O
at	O
Virginia	O
Tech	O
measures	O
the	O
faraday	O
efficiency	O
(	O
the	O
percent	O
of	O
measured	O
output	O
against	O
theoretical	O
output	O
)	O
of	O
the	O
sugar	B-Algorithm
battery	I-Algorithm
's	O
redox	B-Operating_System
reaction	I-Operating_System
.	O
</s>
<s>
As	O
a	O
result	O
,	O
the	O
sugar	B-Algorithm
battery	I-Algorithm
does	O
not	O
depend	O
on	O
the	O
use	O
of	O
complex	O
organic	O
chemicals	O
(	O
for	O
example	O
,	O
adenosine	O
triphosphate	O
)	O
,	O
which	O
are	O
expensive	O
and	O
unstable	O
.	O
</s>
<s>
The	O
researchers	O
developed	O
the	O
design	O
of	O
the	O
sugar	B-Algorithm
battery	I-Algorithm
from	O
the	O
prototyped	O
enzymatic	O
fuel	O
cells	O
,	O
which	O
use	O
enzymes	O
as	O
catalysts	O
in	O
the	O
redox	B-Operating_System
reaction	I-Operating_System
.	O
</s>
<s>
Based	O
on	O
the	O
design	O
of	O
regular	O
enzymatic	O
fuel	O
cells	O
,	O
the	O
sugar	B-Algorithm
battery	I-Algorithm
employs	O
several	O
methods	O
to	O
enlarge	O
the	O
effect	O
produced	O
by	O
the	O
enzymes	O
so	O
that	O
the	O
overall	O
efficiency	O
of	O
the	O
battery	O
is	O
improved	O
.	O
</s>
<s>
The	O
enzymes	O
in	O
sugar	B-Algorithm
battery	I-Algorithm
are	O
no	O
more	O
fixed	O
to	O
the	O
electrode	O
,	O
nor	O
entrapped	O
in	O
a	O
limited	O
space	O
near	O
the	O
electrode	O
.	O
</s>
<s>
The	O
enzymes	O
in	O
the	O
sugar	B-Algorithm
battery	I-Algorithm
can	O
move	O
freely	O
in	O
a	O
larger	O
space	O
and	O
retain	O
the	O
enzymatic	O
activity	O
.	O
</s>
<s>
The	O
corresponding	O
experiments	O
suggest	O
that	O
the	O
non-immobilization	O
method	O
helps	O
the	O
sugar	B-Algorithm
battery	I-Algorithm
to	O
reach	O
a	O
higher	O
and	O
more	O
stable	O
energy	O
density	O
level	O
than	O
the	O
regular	O
enzyme	O
fuel	O
cells	O
with	O
immobilized	O
enzymes	O
.	O
</s>
<s>
Hence	O
,	O
the	O
energy	O
density	O
of	O
the	O
sugar	B-Algorithm
battery	I-Algorithm
increased	O
so	O
that	O
the	O
battery	O
life	O
extended	O
.	O
</s>
<s>
In	O
the	O
sugar	B-Algorithm
battery	I-Algorithm
,	O
the	O
thermo	O
enzymes	O
are	O
produced	O
by	O
Escherichia	O
coli	O
,	O
a	O
kind	O
of	O
bacterium	O
.	O
</s>
<s>
The	O
oxidation	B-Operating_System
reaction	I-Operating_System
inside	O
the	O
sugar	B-Algorithm
battery	I-Algorithm
happens	O
in	O
a	O
synthetic	O
catabolic	O
pathway	O
,	O
which	O
contains	O
13	O
enzymes	O
.	O
</s>
<s>
This	O
pathway	O
is	O
constructed	O
as	O
air-breathing	O
rather	O
than	O
closed	O
so	O
that	O
the	O
researchers	O
ensure	O
the	O
air	O
pressure	O
inside	O
the	O
battery	O
stable	O
and	O
the	O
oxidation	B-Operating_System
reaction	I-Operating_System
goes	O
into	O
completion	O
.	O
</s>
<s>
According	O
to	O
the	O
lab	O
experiments	O
,	O
the	O
sugar	B-Algorithm
battery	I-Algorithm
reaches	O
an	O
electron-transmission	O
efficiency	O
of	O
almost	O
24	O
electrons	O
per	O
monomer	O
glucose	O
,	O
which	O
is	O
the	O
basic	O
unit	O
of	O
organic	O
fuels	O
.	O
</s>
<s>
In	O
comparison	O
,	O
the	O
oxidation	B-Operating_System
reaction	I-Operating_System
in	O
the	O
prototyped	O
enzymatic	O
fuel	O
cells	O
could	O
only	O
generate	O
2	O
electrons	O
per	O
glucose	O
unit	O
,	O
resulting	O
in	O
low	O
energy	O
density	O
.	O
</s>
