January 21, 2016

Battery and Fuel Cell Technologies Compared



Description
Power Density
Specific Power
Energy Density
Specific Weight
kW/litre
kW/kg
Wh/litre
Wh/kg
Lead-acid (LAB)
0.12  
0.08
90
44
Zebra
0.24  
0.16
167
114
Sodium Sulphide (NaS)
0.021
0.17
170
117
Lithium-ion (LIB)
0.22  
0.11
270
120
Siemens PEMFC BZM120 fuel cell
0.257
0.13
1200
MHalblaub comment 22/1/16
Silver Zinc see
Lithium Sulfur Battery or Li-S



325
The 2008 conference paper Submarine Power and Propulsion - Trends and Opportunities by Engineers at BMT Defence Services Ltd, Bath, United Kingdom at http://www.bmtdsl.co.uk/media/1057650/BMTDSL-Submarine-Power-and-Propulsion-Conpaper-Pacific08-Jan08.pdf is very interesting. Page 8 of the paper contains Table.1 (above) - Battery & Fuel Cell Technologies.

Page 7 describes the Zebra battery [Ref 18]. ],  a sodium nickel chloride battery, developed by Rolls-Royce for marine use. See German wikipedia entry on Zebra Battery.

Page 8 comments:

“Lithium ion designs have successfully been developed for automotive applications [Ref. 19]. Their energy density is over twice that of lead acids batteries and it is less than half the weight for the same energy at the 5 hour discharge rate. A unit which is 50cm by 40cm by 40cm has energy of 21kWh and can develop 100kW continuously (i.e. five hour discharge) or 200kW for short periods of time. 

The Table looks like a good vehicle to add more recent data – post 2008.

Pete

3 comments:

MHalblaub said...

Dear Pete,

for the second batch of German Type 212A submarines a new battery type was considered but not used in the end.

It is not necessary to compare the specific power for different solutions because any solution will drain the power from the batteries. There are enough batteries on a submarine to provide full power for the electric engine and the other installations. The point is how long can the batteries sustain the power.

The specific energy density for a fuel cell system is according to the chemical ingredients: Methanol and Oxygen

Methanol has a heat of combustion of 22 MJ/kg ( 1 MJ/Kg <> 277.7 Wh)
To burn or change Methanol to energy for two Methanol molecules three O2 are required. Methanol weights 32 g/mol. O2 also about 32 g/mol. So to make the energy 1.5 more Oxygen mass is required.
Therefore the chemical energy is just 9 MJ/kg for Methanol and Oxygen.

That is still 2.500 Wh per Kg.
Fuel cell efficiency is about 50 % therefore the specific energy weight is still
around 1.200 Wh or ten times more than for any battery system.

For higher power output one would need more fuel cells.

Regards,
MHalblaub

Autumn Leaf said...

Hi Pete,
Great work on your SEA1000 related research into submarine technologies.

A report today (rumours maybe) that TKMS is losing ground in the competition:
http://hotcopper.com.au/resources/australian-submarine-tender-narrows-to-japanese-and-french-bids-germans-lose-ground-sources.1343/#.VqGOJt-qpBc

Tought you might be interested to read this.

Peter Coates said...

Hi Autumn Leaf

Thanks for your comments on my research

and for http://hotcopper.com.au/resources/australian-submarine-tender-narrows-to-japanese-and-french-bids-germans-lose-ground-sources.1343/#.VqGOJt-qpBc . I agree with much of the text but the Reuters Table in that article is getting dated.

Commentaries on the submarine contest seem to date after only about 2 weeks.

Regards

Pete