<s>
A	O
potassium-ion	B-Algorithm
battery	I-Algorithm
or	O
K-ion	O
battery	O
(	O
abbreviated	O
as	O
KIB	O
)	O
is	O
a	O
type	O
of	O
battery	O
and	O
analogue	O
to	O
lithium-ion	O
batteries	O
,	O
using	O
potassium	O
ions	O
for	O
charge	O
transfer	O
instead	O
of	O
lithium	O
ions	O
.	O
</s>
<s>
The	O
prototype	B-Application
device	O
used	O
a	O
potassium	O
anode	O
and	O
a	O
Prussian	O
blue	O
compound	O
as	O
the	O
cathode	O
material	O
for	O
its	O
high	O
electrochemical	O
stability	O
.	O
</s>
<s>
The	O
prototype	B-Application
was	O
successfully	O
used	O
for	O
more	O
than	O
500	O
cycles	O
.	O
</s>
<s>
A	O
recent	O
review	O
showed	O
currently	O
that	O
several	O
pragmatic	O
materials	O
have	O
been	O
successfully	O
used	O
as	O
the	O
anode	O
and	O
cathode	O
for	O
the	O
new	O
generations	O
of	O
potassium-ion	B-Algorithm
batteries	I-Algorithm
.	O
</s>
<s>
For	O
example	O
,	O
the	O
conventional	O
anode	O
material	O
graphite	O
has	O
been	O
shown	O
that	O
it	O
can	O
be	O
used	O
as	O
an	O
anode	O
in	O
a	O
potassium-ion	B-Algorithm
battery	I-Algorithm
.	O
</s>
<s>
After	O
the	O
invention	O
of	O
potassium-ion	B-Algorithm
battery	I-Algorithm
with	O
the	O
prototype	B-Application
device	O
,	O
researchers	O
have	O
increasingly	O
been	O
focusing	O
on	O
enhancing	O
the	O
specific	O
capacity	O
and	O
cycling	O
performance	O
with	O
the	O
application	O
of	O
new	O
materials	O
to	O
electrode	O
and	O
electrolyte	O
.	O
</s>
<s>
A	O
general	O
picture	O
of	O
the	O
material	O
used	O
for	O
potassium-ion	B-Algorithm
battery	I-Algorithm
can	O
be	O
found	O
as	O
follows	O
:	O
</s>
<s>
Whereas	O
with	O
different	O
kinetics	O
,	O
graphite	O
anodes	O
suffer	O
from	O
low	O
capacity	O
retention	O
during	O
cycling	O
within	O
potassium-ion	B-Algorithm
batteries	I-Algorithm
.	O
</s>
<s>
Other	O
types	O
of	O
carbonaceous	O
materials	O
besides	O
graphite	O
have	O
been	O
employed	O
as	O
anode	O
material	O
for	O
potassium-ion	B-Algorithm
battery	I-Algorithm
,	O
such	O
as	O
expanded	O
graphite	O
,	O
carbon	O
nanotubes	O
,	O
carbon	O
nanofibers	O
and	O
also	O
nitrogen	O
or	O
phosphorus-doped	O
carbon	O
materials	O
.	O
</s>
<s>
Conversion	O
anodes	O
which	O
can	O
form	O
compound	O
with	O
potassium	O
ion	O
with	O
boosted	O
storage	O
capacity	O
and	O
reversibility	O
have	O
also	O
been	O
studied	O
to	O
fit	O
for	O
potassium-ion	B-Algorithm
battery	I-Algorithm
.	O
</s>
<s>
Classic	O
alloying	O
anodes	O
such	O
as	O
Si	O
,	O
Sb	O
and	O
Sn	O
that	O
can	O
form	O
alloy	O
with	O
lithium	O
ion	O
during	O
cycling	O
process	O
are	O
also	O
applicable	O
for	O
potassium-ion	B-Algorithm
battery	I-Algorithm
.	O
</s>
<s>
Polyanionic	O
compounds	O
with	O
inductive	O
defects	O
could	O
provide	O
the	O
highest	O
working	O
voltage	O
among	O
other	O
types	O
of	O
cathode	O
for	O
potassium-ion	B-Algorithm
batteries	I-Algorithm
.	O
</s>
<s>
Worth	O
noting	O
is	O
an	O
orthodox	O
approach	O
of	O
using	O
organic	O
compound	O
as	O
cathode	O
for	O
potassium-ion	B-Algorithm
battery	I-Algorithm
,	O
such	O
as	O
PTCDA	O
,	O
a	O
red	O
pigment	O
which	O
can	O
bond	O
with	O
11	O
potassium	O
ion	O
within	O
single	O
molecule	O
.	O
</s>
<s>
Recently	O
,	O
solid	O
polymer	O
electrolyte	O
for	O
all-solid-state	O
potassium-ion	B-Algorithm
battery	I-Algorithm
have	O
attracted	O
much	O
attention	O
due	O
to	O
its	O
flexibility	O
and	O
enhanced	O
safety	O
,	O
Feng	O
et	O
al	O
proposed	O
a	O
poly	O
(	O
propylene	O
carbonate	O
)	O
-KFSI	O
solid	O
polymer	O
electrolyte	O
with	O
the	O
frame	O
work	O
of	O
cellulose	O
non-woven	O
membrane	O
,	O
with	O
boosted	O
ionic	O
conductivity	O
of	O
1.3610	O
−5	O
S	O
cm−1	O
.	O
</s>
<s>
Research	O
on	O
electrolyte	O
for	O
potassium-ion	B-Algorithm
battery	I-Algorithm
is	O
focusing	O
on	O
achieving	O
fast	O
ion	O
diffusion	O
kinetics	O
,	O
stable	O
SEI	O
formation	O
as	O
well	O
as	O
enhanced	O
safety	O
.	O
</s>
<s>
Along	O
with	O
the	O
sodium	B-Algorithm
ion	I-Algorithm
,	O
potassium-ion	O
is	O
the	O
prime	O
chemistry	O
replacement	O
candidate	O
for	O
lithium-ion	O
batteries	O
.	O
</s>
<s>
Another	O
advantage	O
of	O
a	O
potassium-ion	B-Algorithm
battery	I-Algorithm
over	O
a	O
lithium-ion	O
battery	O
is	O
potentially	O
faster	O
charging	O
.	O
</s>
<s>
The	O
prototype	B-Application
employed	O
a	O
electrolyte	O
,	O
though	O
almost	O
all	O
common	O
electrolyte	O
salts	O
can	O
be	O
used	O
.	O
</s>
<s>
Potassium	O
batteries	O
have	O
been	O
proposed	O
for	O
large-scale	O
energy	O
storage	O
given	O
its	O
exceptional	O
cyclability	O
,	O
but	O
current	O
prototypes	B-Application
only	O
withstand	O
a	O
hundred	O
charging	O
cycles	O
.	O
</s>
<s>
The	O
interesting	O
and	O
unique	O
feature	O
of	O
the	O
potassium-ion	B-Algorithm
battery	I-Algorithm
in	O
comparison	O
with	O
other	O
types	B-Algorithm
of	I-Algorithm
batteries	I-Algorithm
is	O
that	O
life	O
on	O
Earth	O
is	O
based	O
on	O
biological	O
potassium-ion	B-Algorithm
batteries	I-Algorithm
.	O
</s>
<s>
This	O
is	O
not	O
only	O
an	O
iconic	O
feature	O
of	O
potassium-ion	B-Algorithm
batteries	I-Algorithm
but	O
also	O
indicates	O
how	O
important	O
it	O
is	O
to	O
understand	O
the	O
role	O
of	O
charge	O
carriers	O
to	O
understand	O
the	O
living	O
mechanism	O
of	O
plants	O
.	O
</s>
<s>
Its	O
charge/discharge	O
potential	O
gap	O
of	O
about	O
50mV	O
is	O
the	O
lowest	O
reported	O
value	O
in	O
metal−air	B-Architecture
batteries	I-Architecture
.	O
</s>
<s>
In	O
comparison	O
,	O
lithium	B-Architecture
–	I-Architecture
air	I-Architecture
batteries	I-Architecture
(	O
)	O
have	O
a	O
much	O
higher	O
overpotential	O
of	O
1	O
–	O
1.5V	O
,	O
which	O
results	O
in	O
60%	O
round-trip	O
efficiency	O
.	O
</s>
