<s>
Aluminium	B-Algorithm
–	I-Algorithm
air	I-Algorithm
batteries	I-Algorithm
(	O
Al	B-Algorithm
–	I-Algorithm
air	I-Algorithm
batteries	I-Algorithm
)	O
produce	O
electricity	O
from	O
the	O
reaction	O
of	O
oxygen	O
in	O
the	O
air	O
with	O
aluminium	O
.	O
</s>
<s>
Aluminium	B-Algorithm
–	I-Algorithm
air	I-Algorithm
batteries	I-Algorithm
are	O
primary	B-Algorithm
cells	I-Algorithm
,	O
i.e.	O
,	O
non-rechargeable	O
.	O
</s>
<s>
Such	O
recycling	O
would	O
be	O
essential	O
if	O
aluminium	B-Algorithm
–	I-Algorithm
air	I-Algorithm
batteries	I-Algorithm
were	O
to	O
be	O
widely	O
adopted	O
.	O
</s>
<s>
Other	O
metals	O
can	O
be	O
used	O
in	O
a	O
similar	O
way	O
,	O
such	O
as	O
lithium-air	B-Architecture
,	O
zinc-air	B-Algorithm
,	O
manganese-air	O
,	O
and	O
sodium-air	O
,	O
some	O
with	O
a	O
higher	O
energy	O
density	O
.	O
</s>
<s>
Technical	O
problems	O
remain	O
to	O
be	O
solved	O
to	O
make	O
Al	B-Algorithm
–	I-Algorithm
air	I-Algorithm
batteries	I-Algorithm
suitable	O
for	O
electric	O
vehicles	O
.	O
</s>
<s>
Modern	O
air	O
cathodes	O
consist	O
of	O
a	O
reactive	O
layer	O
of	O
carbon	O
with	O
a	O
nickel-grid	O
current	O
collector	O
,	O
a	O
catalyst	O
(	O
e.g.	O
,	O
cobalt	B-Algorithm
)	O
,	O
and	O
a	O
porous	O
hydrophobic	O
PTFE	O
film	O
that	O
prevents	O
electrolyte	O
leakage	O
.	O
</s>
<s>
Traditional	O
Al	B-Algorithm
–	I-Algorithm
air	I-Algorithm
batteries	I-Algorithm
had	O
a	O
limited	O
shelf	O
life	O
,	O
because	O
the	O
aluminium	O
reacted	O
with	O
the	O
electrolyte	O
and	O
produced	O
hydrogen	O
when	O
the	O
battery	O
was	O
not	O
in	O
use	O
;	O
this	O
is	O
no	O
longer	O
the	O
case	O
with	O
modern	O
designs	O
.	O
</s>
<s>
These	O
batteries	O
can	O
be	O
used	O
as	O
reserve	B-Algorithm
batteries	I-Algorithm
in	O
telephone	O
exchanges	O
and	O
as	O
backup	O
power	O
sources	O
.	O
</s>
<s>
Aluminium	B-Algorithm
–	I-Algorithm
air	I-Algorithm
batteries	I-Algorithm
may	O
become	O
an	O
effective	O
solution	O
for	O
marine	O
applications	O
due	O
to	O
their	O
high	O
energy	O
density	O
,	O
low	O
cost	O
,	O
and	O
the	O
abundance	O
of	O
aluminum	O
,	O
with	O
no	O
emissions	O
at	O
the	O
point	O
of	O
use	O
in	O
boats	O
and	O
ships	O
.	O
</s>
