Lead–acid battery
Nickel–metal hydride battery
Lithium–iodide battery
Top Trumps – “Energy” Edition
intern challenges its readers to a game of cards. Do you know the differences be­tween
today’s energy storage devices and those currently being explored? Which will come
up trumps, and why? Simply cut out the ten cards, start playing, and find out!
To transform the energy sector, Germany needs better media for storing
energy. However, the current market can
be confusing, and this makes it difficult
to assess the advantages and disadvantages of the different systems.
If you would like to learn about some
current and future energy storage devices
– i.e. batteries – to get a better overview,
simply cut out the ten cards and play a
game of Top Trumps. The aim of the game
is to spot the best attribute of the battery
on top of your pile and play it to win the
other players’ cards (if you’re not familiar
with the rules, click here). You’ll also
learn which storage media are the focus
of research at Jülich’s institutes in the
field of energy and climate research.
“Supercap” battery
“Supercap” battery
Metal–air battery*
Energ y densit y:
Power densit y:
Cost:
Energ y densit y:
Safety :
Power densit y:
Lifetime:
Cost:
Energ
y densit
Efficie
ncy: y:
Safety :
Power densit y:
Lifetime:
Cost:
Efficiency:
Safety :
Tested in buses
that were
recharged
€ 300-4,000/kWh
through inducTested
3-20 Wh/kg
buses
tion atinevery
++
that
buswere
stop.
2,000 -10,00 0 W/kg
500,0 00-1,0 00,00 0 cycles recharged
€ 300-4,000/kWh
throug
Potenthialinduc1,600
-8,600
95-10
0 % Wh/kg
tion
at logy
every
techno
++
333-2,000 W/kg
bus
stop.
being
explored
500,0 00-1,0 00,00 0 cycles
Not yet foreseeable
for batteries in
95-10 0 %
laptops etc.
+
3-20 Wh/kg
2,000 -10,00 0 W/kg
Lifetime:
200-1,000 cycles
Efficiency:
80 %
Subject of research at IEK-1, IEK-9
* Data from iron–zinc–air cells
Selected battery attributes
Energy density in watt hours per kilogram (Wh/kg): Energy contained in a
cell. The higher the energy density,
the more electricity can be obtained
at the same voltage.
25-50 Wh/kg
Power density:
75-300 W/kg
Cost:
€ 50-300/kWh
Safety:
+
Lifetime:
Efficiency:
Common
battery,
well-known as
a conventional
car battery.
Energy density:
40-80 Wh/kg
Power density:
100-200 W/kg
Cost:
€ 2,000/kWh
Safety:
++
200-1,500 cycles
Lifetime:
500-2,000 cycles
70-85 %
Efficiency:
70-80 %
Subject of research at IEK-3
Conventional
battery for
small electronic
devices from
the pocket torch
to the wireless
mouse.
Energy density:
240-560 Wh/kg
Power density:
245 W/kg
Cost:
€ 2,000/kWh
Safety:
++
Lifetime:
Not known
Efficiency:
Not known
Developed
for medical
devices such
as pacemakers.
To date, only
rechargeable to
a limited extent.
Subject of research at IEK-3
Lithium-ion battery
Lithium–sulfur battery
Redox flow battery (V*)
Power density in watts per kilogram
(W/kg): Measure of the weight of a
cell. The higher the power density,
the more energy can be stored per
kilogram. Current technology is
designed to have a low power density – normal batteries only store
about one watt.
Cost in euros per kilowatt hour (€/
kWh): Material and production costs
for the storage of one kilowatt hour
with the respective system.
Safety: Estimation of the risks for
humans and the environment. High
operating temperatures or the use
of toxic substances reduce safety.
Assessment scale from “--” to “o” to
“++”.
Energy density:
70-410 Wh/kg
Power density:
150-315 W/kg
Cost:
€ 200-1,800/kWh
Safety:
o
Lifetime:
300-3,000 cycles
Efficiency:
90-95 %
Common battery
in appliances
such as mobile
phones or laptops. A flammable
electrolyte and
the comparatively
high reactivity of
the electrodes
reduce its safety.
Subject of research at IEK-1, IEK-2, IEK-3, IEK-9
Energy density:
60-80 Wh/kg
Power density:
Variable
Cost:
€ 100-1,000/kWh
Safety:
o
Lifetime:
10,000 cycles
Efficiency:
70-85 %
Stationary
energy storage
device in the
test phase.
Tank size and
membrane area
determine the
power density.
Energy density:
1,000-2,500 Wh/kg
Power density:
2,000-4,000 W/kg
Cost:
€ 100 /kWh
Safety:
--
Lifetime:
50-200 cycles
Efficiency:
85 %
Potential
future battery
for electric cars.
Safety risks stem
from the short
lifetime, toxic
gases in case of
fire, and a toxic
electrolyte.
*Data from vanadium-based cells
Metal–air battery*
Sodium–sulfur battery*
Metal–metal oxide battery
Lifetime: Number of charge and
discharge cycles of a cell, until it can
be recharged to less than 60 % of its
original capacity. A cycle corresponds to a discharge of 80 %.
Efficiency: Relationship between the
amount of electricity required to fully charge the cell and the amount of
electricity released when discharging.
All data sources on IEK-9’s website:
http://www.fz-juelich.de/iek/iek-9
Images: tournee (p. 8, hand), Petair (p. 8, bus stop), zest_marina (p. 9, lead–acid battery), djama (p. 9, nickel–metal hydride
battery), AK-DigiArt (p. 9, lithium–iodide battery), ekipaj (p. 9, lithium-ion battery), ilynx_v (p. 9, lithium–sulfur battery),
WoGi (p. 9, metal–air battery/accumulator), mhristov (p. 9, metal–air battery/laptop, mobile phone, tablet)
Energy density:
intern 2 | 2014
Energy density:
1,600-8,600 Wh/kg
Power density:
333-2,000 W/kg
Cost:
Not yet foreseeable
Safety:
+
Lifetime:
Efficiency:
Potential
technology
being explored
for batteries in
laptops etc.
Energy density:
103 Wh/kg
Power density:
100 W/kg
Cost:
€ 200-900/kWh
Safety:
-
200-1,000 cycles
Lifetime:
4,500 cycles
80 %
Efficiency:
89 %
Subject of research at IEK-1, IEK-9
* Data from iron–zinc–air cells
*High-temperature battery
Stationary
storage device
based on melted
electrodes. First
commercial
batteries are
being tested.
Energy density:
1,000 Wh/kg
Power density:
1,000 W/kg
Cost:
> € 150/kWh
Safety:
-
Lifetime:
> 200 cycles
Efficiency:
70-80 %
Subject of research at IEK-1, IEK-2, IEK-9
*High-temperature battery
Vision for a
stationary
storage device:
combination of
fuel cells with
metal (oxide)
as the storage
medium.
Thermal risk.