<s>
A	O
zinc	B-Algorithm
–	I-Algorithm
carbon	I-Algorithm
battery	I-Algorithm
(	O
or	O
carbon	B-Algorithm
zinc	I-Algorithm
battery	I-Algorithm
in	O
U.S.	O
English	O
)	O
is	O
a	O
dry	B-Algorithm
cell	I-Algorithm
primary	B-Algorithm
battery	I-Algorithm
that	O
provides	O
direct	O
electric	O
current	O
from	O
the	O
electrochemical	O
reaction	O
between	O
zinc	B-Application
and	O
manganese	O
dioxide	O
(	O
MnO2	O
)	O
in	O
the	O
presence	O
of	O
an	O
electrolyte	O
.	O
</s>
<s>
It	O
produces	O
a	O
voltage	O
of	O
about	O
1.5	O
volts	O
between	O
the	O
zinc	B-Application
anode	O
,	O
which	O
is	O
typically	O
constructed	O
as	O
a	O
cylindrical	O
container	O
for	O
the	O
battery	O
cell	O
,	O
and	O
a	O
carbon	O
rod	O
surrounded	O
by	O
a	O
compound	O
with	O
a	O
higher	O
Standard	O
electrode	O
potential	O
(	O
positive	O
polarity	O
)	O
,	O
known	O
as	O
the	O
cathode	O
,	O
that	O
collects	O
the	O
current	O
from	O
the	O
manganese	O
dioxide	O
electrode	O
.	O
</s>
<s>
The	O
name	O
"	O
zinc-carbon	O
"	O
is	O
slightly	O
misleading	O
as	O
it	O
implies	O
that	O
carbon	O
is	O
acting	O
as	O
the	O
oxidizing	O
agent	O
rather	O
than	O
the	O
manganese	O
dioxide	O
.	O
</s>
<s>
General-purpose	O
batteries	O
may	O
use	O
an	O
acidic	O
aqueous	O
paste	O
of	O
ammonium	O
chloride	O
(	O
NH4Cl	O
)	O
as	O
electrolyte	O
,	O
with	O
some	O
zinc	B-Application
chloride	O
solution	O
on	O
a	O
paper	O
separator	O
to	O
act	O
as	O
what	O
is	O
known	O
as	O
a	O
salt	O
bridge	O
.	O
</s>
<s>
Heavy-duty	O
types	O
use	O
a	O
paste	O
primarily	O
composed	O
of	O
zinc	B-Application
chloride	O
(	O
ZnCl2	O
)	O
.	O
</s>
<s>
Zinc	B-Algorithm
–	I-Algorithm
carbon	I-Algorithm
batteries	I-Algorithm
were	O
the	O
first	O
commercial	O
dry	O
batteries	O
,	O
developed	O
from	O
the	O
technology	O
of	O
the	O
wet	O
Leclanché	B-Algorithm
cell	I-Algorithm
.	O
</s>
<s>
They	O
are	O
still	O
useful	O
in	O
low-drain	O
or	O
intermittent-use	O
devices	O
such	O
as	O
remote	B-Protocol
controls	I-Protocol
,	O
flashlights	O
,	O
clocks	O
or	O
transistor	O
radios	O
.	O
</s>
<s>
Zinc	B-Application
–	O
carbon	O
dry	B-Algorithm
cells	I-Algorithm
are	O
single-use	O
primary	B-Algorithm
cells	I-Algorithm
.	O
</s>
<s>
Zinc-carbon	B-Algorithm
batteries	I-Algorithm
today	O
have	O
been	O
mostly	O
replaced	O
by	O
the	O
more	O
efficient	O
and	O
safe	O
alkaline	B-Algorithm
batteries	I-Algorithm
.	O
</s>
<s>
By	O
1876	O
,	O
the	O
wet	O
Leclanché	B-Algorithm
cell	I-Algorithm
was	O
made	O
with	O
a	O
compressed	O
block	O
of	O
manganese	O
dioxide	O
.	O
</s>
<s>
In	O
1886	O
,	O
Carl	O
Gassner	O
patented	O
a	O
"	O
dry	O
"	O
version	O
by	O
using	O
a	O
casing	O
made	O
of	O
zinc	B-Application
sheet	O
metal	O
as	O
the	O
anode	O
and	O
a	O
paste	O
of	O
plaster	O
of	O
Paris	O
(	O
and	O
later	O
,	O
graphite	B-Application
powder	O
)	O
.	O
</s>
<s>
In	O
1900	O
,	O
Gassner	O
demonstrated	O
dry	B-Algorithm
cells	I-Algorithm
for	O
portable	O
lighting	O
at	O
the	O
World	O
's	O
Fair	O
in	O
Paris	O
.	O
</s>
<s>
Continual	O
improvements	O
were	O
made	O
to	O
the	O
stability	O
and	O
capacity	O
of	O
zinc	B-Algorithm
–	I-Algorithm
carbon	I-Algorithm
cells	I-Algorithm
throughout	O
the	O
20th	O
century	O
;	O
by	O
the	O
end	O
of	O
the	O
century	O
the	O
capacities	O
had	O
increased	O
fourfold	O
over	O
the	O
1910	O
equivalent	O
.	O
</s>
<s>
Improvements	O
include	O
the	O
use	O
of	O
purer	O
grades	O
of	O
manganese	O
dioxide	O
,	O
the	O
addition	O
of	O
graphite	B-Application
powder	O
to	O
the	O
manganese	O
dioxide	O
to	O
lower	O
internal	O
resistance	O
,	O
better	O
sealing	O
,	O
and	O
purer	O
zinc	B-Application
for	O
the	O
negative	O
electrode	O
.	O
</s>
<s>
Zinc-chloride	O
cells	O
(	O
usually	O
marketed	O
as	O
"	O
heavy	O
duty	O
"	O
batteries	O
)	O
use	O
a	O
higher	O
concentration	O
of	O
anolyte	O
(	O
or	O
anode	O
electrolyte	O
)	O
which	O
is	O
primarily	O
composed	O
of	O
zinc	B-Application
chloride	O
,	O
which	O
can	O
produce	O
a	O
more	O
consistent	O
voltage	O
output	O
in	O
high	O
drain	O
applications	O
.	O
</s>
<s>
Side	O
reactions	O
between	O
impurities	O
in	O
the	O
zinc	B-Application
metal/zinc	O
chloride	O
anode	O
,	O
and	O
the	O
ammonium	O
chloride	O
electrolyte	O
can	O
increase	O
the	O
self-discharge	O
rate	O
and	O
promote	O
corrosion	O
of	O
the	O
cell	O
.	O
</s>
<s>
Formerly	O
,	O
the	O
zinc	B-Application
was	O
coated	O
with	O
mercury	O
(	O
Hg	O
)	O
to	O
form	O
an	O
amalgam	O
,	O
protecting	O
it	O
.	O
</s>
<s>
Manufacturers	O
must	O
now	O
use	O
more	O
highly	O
purified	O
zinc	B-Application
to	O
prevent	O
local	O
action	O
and	O
self-discharge	O
.	O
</s>
<s>
zinc	B-Algorithm
–	I-Algorithm
carbon	I-Algorithm
batteries	I-Algorithm
accounted	O
for	O
20%	O
of	O
all	O
portable	O
batteries	O
in	O
the	O
United	O
Kingdom	O
and	O
18%	O
in	O
the	O
E.U.	O
</s>
<s>
The	O
container	O
of	O
the	O
zinc	B-Application
–	O
carbon	O
dry	B-Algorithm
cell	I-Algorithm
is	O
a	O
zinc	B-Application
can	O
(	O
anode	O
)	O
.	O
</s>
<s>
The	O
paper	O
separator	O
prevents	O
a	O
short	O
circuit	O
from	O
forming	O
by	O
protecting	O
the	O
zinc	B-Application
can	O
from	O
making	O
contact	O
with	O
the	O
cathode	O
,	O
which	O
is	O
a	O
mixture	O
of	O
powdered	O
carbon	O
(	O
usually	O
graphite	B-Application
powder	O
)	O
and	O
manganese	O
(	O
IV	O
)	O
oxide	O
(	O
MnO2	O
)	O
,	O
which	O
is	O
packed	O
around	O
a	O
carbon	O
rod	O
.	O
</s>
<s>
Early	O
types	O
,	O
and	O
low-cost	O
cells	O
,	O
use	O
a	O
separator	O
consisting	O
of	O
a	O
layer	O
of	O
starch	B-Application
or	O
flour	O
.	O
</s>
<s>
A	O
layer	O
of	O
starch-coated	O
paper	O
is	O
used	O
in	O
modern	O
cells	O
,	O
which	O
is	O
thinner	O
and	O
allows	O
more	O
manganese	O
dioxide	O
to	O
be	O
used	O
.	O
</s>
<s>
Flat	O
cells	O
are	O
stacked	O
and	O
the	O
whole	O
assembly	O
is	O
coated	O
in	O
wax	O
to	O
prevent	O
electrolyte	O
evaporation	B-Algorithm
.	O
</s>
<s>
Zinc	B-Algorithm
–	I-Algorithm
carbon	I-Algorithm
batteries	I-Algorithm
are	O
a	O
reliable	O
source	O
of	O
power	O
for	O
appliances	O
that	O
consume	O
little	O
energy	O
,	O
like	O
remote	B-Protocol
controls	I-Protocol
for	O
television	O
,	O
clocks	O
,	O
smoke	O
detectors	O
and	O
flashlights	O
.	O
</s>
<s>
Zinc-carbon	B-Algorithm
batteries	I-Algorithm
were	O
in	O
common	O
use	O
with	O
hand-cranked	O
telephone	B-Algorithm
magneto	I-Algorithm
phones	O
,	O
powering	O
the	O
microphone	O
and	O
speaker	O
.	O
</s>
<s>
In	O
a	O
zinc	B-Application
–	O
carbon	O
dry	B-Algorithm
cell	I-Algorithm
,	O
the	O
outer	O
zinc	B-Application
container	O
is	O
the	O
negatively	O
charged	O
terminal	O
.	O
</s>
<s>
The	O
zinc	B-Application
is	O
oxidised	B-Operating_System
by	O
the	O
charge	O
carrier	O
,	O
chloride	O
anion	O
(	O
Cl−	O
)	O
into	O
ZnCl2	O
,	O
via	O
the	O
following	O
half-reactions	B-Operating_System
:	O
</s>
<s>
If	O
zinc	B-Application
chloride	O
is	O
substituted	O
for	O
ammonium	O
chloride	O
as	O
the	O
electrolyte	O
,	O
the	O
anode	O
reaction	O
remains	O
the	O
same	O
:	O
</s>
<s>
and	O
the	O
cathode	O
reaction	O
produces	O
zinc	B-Application
hydroxide	O
and	O
manganese(III )	O
oxide	O
.	O
</s>
<s>
The	O
anode	O
(	O
zinc	B-Application
)	O
reaction	O
is	O
comparatively	O
simple	O
with	O
a	O
known	O
potential	O
.	O
</s>
<s>
The	O
zinc-chloride	O
cell	O
,	O
frequently	O
referred	O
to	O
as	O
a	O
heavy-duty	O
,	O
extra-heavy-duty	O
,	O
super-heavy-duty	O
,	O
or	O
super-extra-heavy-duty	O
battery	O
,	O
is	O
an	O
improvement	O
on	O
the	O
original	O
zinc	B-Algorithm
–	I-Algorithm
carbon	I-Algorithm
cell	I-Algorithm
,	O
using	O
purer	O
chemicals	O
and	O
giving	O
a	O
longer	O
service	O
life	O
and	O
steadier	O
voltage	O
output	O
as	O
it	O
is	O
used	O
and	O
offering	O
about	O
twice	O
the	O
service	O
life	O
of	O
general-purpose	O
zinc	B-Algorithm
–	I-Algorithm
carbon	I-Algorithm
cells	I-Algorithm
,	O
or	O
up	O
to	O
four	O
times	O
in	O
continuous-use	O
or	O
high-drain	O
applications	O
.	O
</s>
<s>
This	O
is	O
still	O
a	O
fraction	O
of	O
the	O
output	O
of	O
an	O
alkaline	B-Algorithm
cell	I-Algorithm
,	O
however	O
.	O
</s>
<s>
Alkaline	B-Algorithm
batteries	I-Algorithm
offer	O
up	O
to	O
eight	O
times	O
the	O
battery	O
life	O
of	O
zinc	B-Algorithm
–	I-Algorithm
carbon	I-Algorithm
batteries	I-Algorithm
,	O
especially	O
in	O
continuous-use	O
or	O
high-drain	O
applications	O
.	O
</s>
<s>
Manufacturers	O
recommend	O
storage	O
of	O
zinc	B-Algorithm
–	I-Algorithm
carbon	I-Algorithm
batteries	I-Algorithm
at	O
room	O
temperature	O
;	O
storage	O
at	O
higher	O
temperatures	O
reduces	O
the	O
expected	O
service	O
life	O
.	O
</s>
<s>
Zinc	B-Algorithm
–	I-Algorithm
carbon	I-Algorithm
batteries	I-Algorithm
may	O
be	O
frozen	O
without	O
damage	O
;	O
manufacturers	O
recommend	O
that	O
they	O
be	O
returned	O
to	O
normal	O
room	O
temperature	O
before	O
use	O
,	O
and	O
that	O
condensation	O
on	O
the	O
battery	O
jacket	O
must	O
be	O
avoided	O
.	O
</s>
<s>
By	O
the	O
end	O
of	O
the	O
20th	O
century	O
,	O
the	O
storage	O
life	O
of	O
zinc	B-Algorithm
–	I-Algorithm
carbon	I-Algorithm
cells	I-Algorithm
had	O
improved	O
fourfold	O
over	O
expected	O
life	O
in	O
1910	O
.	O
</s>
<s>
Zinc	B-Algorithm
–	I-Algorithm
carbon	I-Algorithm
cells	I-Algorithm
have	O
a	O
short	O
shelf	O
life	O
,	O
as	O
the	O
zinc	B-Application
is	O
attacked	O
by	O
ammonium	O
chloride	O
.	O
</s>
<s>
The	O
zinc	B-Application
container	O
becomes	O
thinner	O
as	O
the	O
cell	O
is	O
used	O
,	O
because	O
zinc	B-Application
metal	O
is	O
oxidized	O
to	O
zinc	B-Application
ions	O
.	O
</s>
<s>
When	O
the	O
zinc	B-Application
case	O
thins	O
enough	O
,	O
zinc	B-Application
chloride	O
begins	O
to	O
leak	O
out	O
of	O
the	O
battery	O
.	O
</s>
<s>
The	O
old	O
dry	B-Algorithm
cell	I-Algorithm
is	O
not	O
leak-proof	O
and	O
becomes	O
very	O
sticky	O
as	O
the	O
paste	O
leaks	O
through	O
the	O
holes	O
in	O
the	O
zinc	B-Application
case	O
.	O
</s>
<s>
The	O
zinc	B-Application
casing	O
in	O
the	O
dry	B-Algorithm
cell	I-Algorithm
gets	O
thinner	O
even	O
when	O
the	O
cell	O
is	O
not	O
being	O
used	O
,	O
because	O
the	O
ammonium	O
chloride	O
inside	O
the	O
battery	O
reacts	O
with	O
the	O
zinc	B-Application
.	O
</s>
<s>
An	O
"	O
inside-out	O
"	O
form	O
with	O
a	O
carbon	O
cup	O
and	O
zinc	B-Application
vanes	O
on	O
the	O
interior	O
,	O
while	O
more	O
leak-resistant	O
,	O
has	O
not	O
been	O
manufactured	O
since	O
the	O
1960s	O
.	O
</s>
<s>
This	O
picture	O
shows	O
the	O
zinc	B-Application
container	O
of	O
fresh	O
batteries	O
at	O
(	O
a	O
)	O
,	O
and	O
discharged	O
batteries	O
at	O
(	O
b	O
)	O
and	O
(	O
c	O
)	O
.	O
</s>
<s>
The	O
battery	O
shown	O
at	O
(	O
c	O
)	O
had	O
a	O
polyethylene	O
protection	O
film	O
(	O
mostly	O
removed	O
in	O
the	O
photo	O
)	O
to	O
keep	O
the	O
zinc	B-Application
oxide	O
inside	O
the	O
casing	O
.	O
</s>
<s>
Thousands	O
of	O
tons	O
of	O
zinc	B-Algorithm
–	I-Algorithm
carbon	I-Algorithm
batteries	I-Algorithm
are	O
discarded	O
every	O
year	O
around	O
the	O
world	O
and	O
are	O
often	O
not	O
recycled	O
.	O
</s>
<s>
In	O
Europe	O
,	O
battery	O
disposal	O
is	O
controlled	O
by	O
the	O
WEEE	O
Directive	O
and	O
Battery	O
Directive	O
regulations	O
,	O
and	O
as	O
such	O
zinc	B-Algorithm
–	I-Algorithm
carbon	I-Algorithm
batteries	I-Algorithm
must	O
not	O
be	O
thrown	O
out	O
with	O
domestic	O
waste	O
.	O
</s>
