<s>
A	O
sodium	B-Architecture
–	I-Architecture
sulfur	I-Architecture
battery	I-Architecture
is	O
a	O
type	O
of	O
molten-salt	B-Architecture
battery	I-Architecture
that	O
uses	O
liquid	O
sodium	O
and	O
liquid	O
sulfur	O
electrodes	O
.	O
</s>
<s>
Despite	O
their	O
low	O
cost	O
,	O
molten	O
sodium-sulfur	B-Architecture
batteries	I-Architecture
suffer	O
from	O
safety	O
and	O
durability	O
issues	O
,	O
such	O
as	O
a	O
short	O
cycle	O
life	O
of	O
fewer	O
than	O
1000	O
cycles	O
on	O
average	O
.	O
</s>
<s>
A	O
similar	O
type	O
of	O
battery	O
called	O
the	O
ZEBRA	B-Algorithm
battery	I-Algorithm
,	O
which	O
uses	O
a	O
/	O
cathode	O
in	O
place	O
of	O
sulfur	O
,	O
has	O
had	O
greater	O
commercial	O
interest	O
in	O
the	O
past	O
,	O
but	O
as	O
of	O
2023	O
there	O
are	O
no	O
commercial	O
manufacturers	O
of	O
ZEBRA	O
.	O
</s>
<s>
Typical	O
batteries	O
have	O
a	O
solid	O
electrolyte	O
membrane	O
between	O
the	O
anode	O
and	O
cathode	O
,	O
compared	O
with	O
liquid-metal	B-Architecture
batteries	I-Architecture
where	O
the	O
anode	O
,	O
the	O
cathode	O
and	O
the	O
membrane	O
are	O
liquids	O
.	O
</s>
<s>
The	O
entire	O
cell	O
is	O
enclosed	O
by	O
a	O
steel	O
casing	O
that	O
is	O
protected	O
,	O
usually	O
by	O
chromium	B-Language
and	O
molybdenum	O
,	O
from	O
corrosion	O
on	O
the	O
inside	O
.	O
</s>
<s>
An	O
essential	O
part	O
of	O
the	O
cell	O
is	O
the	O
presence	O
of	O
a	O
BASE	O
(	O
beta-alumina	B-Algorithm
solid	I-Algorithm
electrolyte	I-Algorithm
)	O
membrane	O
,	O
which	O
selectively	O
conducts	O
Na+	O
.	O
</s>
<s>
The	O
sodium	O
is	O
separated	O
by	O
a	O
beta-alumina	B-Algorithm
solid	I-Algorithm
electrolyte	I-Algorithm
(	O
BASE	O
)	O
cylinder	O
from	O
the	O
container	O
of	O
molten	O
sulfur	O
,	O
which	O
is	O
fabricated	O
from	O
an	O
inert	O
metal	O
serving	O
as	O
the	O
cathode	O
.	O
</s>
<s>
To	O
tackle	O
this	O
challenge	O
,	O
case	O
studies	O
to	O
couple	O
sodium-sulfur	B-Architecture
batteries	I-Architecture
to	O
thermal	O
solar	O
energy	O
systems	O
.	O
</s>
<s>
Early	O
on	O
the	O
morning	O
of	O
September	O
21	O
,	O
2011	O
,	O
a	O
2000	O
kilowatt	O
NaS	B-Architecture
battery	I-Architecture
system	O
manufactured	O
by	O
NGK	O
,	O
owned	O
by	O
Tokyo	O
Electric	O
Power	O
Company	O
used	O
for	O
storing	O
electricity	O
and	O
installed	O
at	O
the	O
Tsukuba	O
,	O
Japan	O
Mitsubishi	O
Materials	O
Corporation	O
plant	O
caught	O
fire	O
.	O
</s>
<s>
Following	O
the	O
incident	O
,	O
NGK	O
temporarily	O
suspended	O
production	O
of	O
NaS	B-Architecture
batteries	I-Architecture
.	O
</s>
<s>
In	O
2014	O
researchers	O
identified	O
a	O
liquid	O
sodium-caesium	O
alloy	O
that	O
operates	O
at	O
150°C	O
and	O
produces	O
420	O
milliampere-hours	O
per	O
gram	O
.	O
</s>
<s>
The	O
lower	O
operating	O
temperature	O
allowed	O
the	O
use	O
of	O
a	O
less-expensive	O
polymer	B-Language
external	O
casing	O
instead	O
of	O
steel	O
,	O
offsetting	O
some	O
of	O
the	O
increased	O
cost	O
associated	O
with	O
using	O
caesium	O
.	O
</s>
<s>
The	O
NaS	B-Architecture
battery	I-Architecture
was	O
one	O
of	O
four	O
battery	B-Algorithm
types	I-Algorithm
selected	O
as	O
candidates	O
for	O
intensive	O
research	O
by	O
MITI	O
as	O
part	O
of	O
the	O
"	O
Moonlight	O
Project	O
"	O
in	O
1980	O
.	O
</s>
<s>
The	O
other	O
three	O
were	O
improved	O
lead	B-Device
–	I-Device
acid	I-Device
,	O
redox	O
flow	O
(	O
vanadium	O
type	O
)	O
,	O
and	O
zinc-bromide	B-Algorithm
batteries	I-Algorithm
.	O
</s>
<s>
A	O
consortium	O
formed	O
by	O
TEPCO	O
(	O
Tokyo	O
Electric	O
Power	O
Co	O
.	O
)	O
and	O
NGK	O
(	O
NGK	O
Insulators	O
Ltd	O
.	O
)	O
declared	O
their	O
interest	O
in	O
researching	O
the	O
NaS	B-Architecture
battery	I-Architecture
in	O
1983	O
,	O
and	O
became	O
the	O
primary	O
drivers	O
behind	O
the	O
development	O
of	O
this	O
type	O
ever	O
since	O
.	O
</s>
<s>
TEPCO	O
chose	O
the	O
NaS	B-Architecture
battery	I-Architecture
because	O
all	O
its	O
component	O
elements	O
(	O
sodium	O
,	O
sulfur	O
and	O
ceramics	O
)	O
are	O
abundant	O
in	O
Japan	O
.	O
</s>
<s>
The	O
commercial	O
NaS	B-Architecture
battery	I-Architecture
bank	O
offers	O
:	O
</s>
<s>
A	O
demonstration	O
project	O
used	O
NaS	B-Architecture
battery	I-Architecture
at	O
Japan	O
Wind	O
Development	O
Co.	O
’	O
s	O
Miura	O
Wind	O
Park	O
in	O
Japan	O
.	O
</s>
<s>
In	O
2010	O
Xcel	O
Energy	O
announced	O
that	O
it	O
would	O
test	O
a	O
wind	O
farm	O
energy	O
storage	O
battery	O
based	O
on	O
twenty	O
50kW	O
sodium	B-Architecture
–	I-Architecture
sulfur	I-Architecture
batteries	I-Architecture
.	O
</s>
<s>
Since	O
then	O
,	O
NGK	O
announced	O
several	O
large	O
scale	O
deployments	O
including	O
a	O
virtual	O
plant	O
distributed	O
on	O
10	O
sites	O
in	O
UAE	B-Device
totaling	O
108	O
MW/648	O
MWh	O
in	O
2019	O
.	O
</s>
<s>
NaS	B-Architecture
batteries	I-Architecture
can	O
be	O
deployed	O
to	O
support	O
the	O
electric	O
grid	O
,	O
or	O
for	O
stand-alone	O
renewable	O
power	O
applications	O
.	O
</s>
<s>
Under	O
some	O
market	O
conditions	O
,	O
NaS	B-Architecture
batteries	I-Architecture
provide	O
value	O
via	O
energy	O
arbitrage	O
(	O
charging	O
battery	O
when	O
electricity	O
is	O
abundant/cheap	O
,	O
and	O
discharging	O
into	O
the	O
grid	O
when	O
electricity	O
is	O
more	O
valuable	O
)	O
and	O
voltage	O
regulation	O
.	O
</s>
<s>
NaS	B-Architecture
batteries	I-Architecture
are	O
a	O
possible	O
energy	O
storage	O
technology	O
to	O
support	O
renewable	O
energy	O
generation	O
,	O
specifically	O
wind	O
farms	O
and	O
solar	O
generation	O
plants	O
.	O
</s>
<s>
These	O
types	B-Algorithm
of	I-Algorithm
batteries	I-Algorithm
present	O
an	O
option	O
for	O
energy	O
storage	O
in	O
locations	O
where	O
other	O
storage	O
options	O
are	O
not	O
feasible	O
.	O
</s>
<s>
In	O
2016	O
,	O
the	O
Mitsubishi	O
Electric	O
Corporation	O
commissioned	O
the	O
world	O
's	O
largest	O
sodium	B-Architecture
–	I-Architecture
sulfur	I-Architecture
battery	I-Architecture
in	O
Fukuoka	O
Prefecture	O
,	O
Japan	O
.	O
</s>
<s>
Because	O
of	O
its	O
high	O
energy	O
density	O
,	O
the	O
NaS	B-Architecture
battery	I-Architecture
has	O
been	O
proposed	O
for	O
space	O
applications	O
.	O
</s>
<s>
The	O
first	O
large-scale	O
use	O
of	O
sodium	B-Architecture
–	I-Architecture
sulfur	I-Architecture
batteries	I-Architecture
was	O
in	O
the	O
Ford	O
"	O
Ecostar	O
"	O
demonstration	O
vehicle	O
,	O
an	O
electric	O
vehicle	O
prototype	O
in	O
1991	O
.	O
</s>
<s>
One	O
of	O
the	O
main	O
shortcomings	O
of	O
traditional	O
sodium-sulfur	B-Architecture
batteries	I-Architecture
is	O
that	O
they	O
require	O
high	O
temperatures	O
to	O
operate	O
.	O
</s>
<s>
Research	O
and	O
development	O
of	O
sodium-sulfur	B-Architecture
batteries	I-Architecture
that	O
can	O
operate	O
at	O
room	O
temperature	O
is	O
ongoing	O
.	O
</s>
<s>
The	O
shuttle	O
effect	O
in	O
sodium-sulfur	B-Architecture
batteries	I-Architecture
leads	O
to	O
a	O
loss	O
of	O
capacity	O
,	O
which	O
can	O
be	O
defined	O
as	O
a	O
reduction	O
in	O
the	O
amount	O
of	O
energy	O
that	O
can	O
be	O
extracted	O
from	O
the	O
battery	O
.	O
</s>
