Saft and ESMA to Cooperate on Supercapacitor Development, Production and Commercialization; Heavy Diesels First Target
11 May 2009
Saft has signed an agreement with ESMA, a Russian company, to cooperate in the development, production and commercialization of supercapacitors based on ESMA’s technology.
The agreement enables Saft to add the new supercapacitor technology to its portfolio of leading edge battery technologies. The first results will be seen later in 2009, when Saft’s US manufacturing facility in Valdosta, GA begins production of a new generation of asymmetric nickel supercapacitors that will work in combination with batteries on heavy vehicles in a large variety of markets including, but not limited to, industry or public transportation.
By providing effective and reliable starting power for large diesel engines at low temperatures or in frequent stop-start usage the supercapacitors will allow the vehicle battery to be optimized for the application.
In addition to the main cooperative agreement with ESMA, Saft has also signed a distribution agreement for the supercapacitors with KBi (Kold Ban International), a US company specializing in diesel engine starting systems that is already an established ESMA distributor for North America.
Saft manufacturers a range of advanced batteries for a large range of applications using lithium and nickel chemistries, including lithium-ion, lithium-thionyl chloride (Li-SOCl2), lithium-sulfur dioxide (Li-SO2), lithium-manganese dioxide (Li-MnO2), nickel-cadmium (Ni-Cd), nickel-hydrogen (Ni-H2), and nickel-metal hydride (NiMH).
ESMA’s patented asymmetric nickel capacitors feature one battery electrode mated with a double layer charge storage (capacitor) electrode. This combination offers a number of advantages over the standard, more common symmetric design including: improved safety; higher specific energy; more stable operating voltage; lower materials and manufacturing costs; voltage self-balancing in high-voltage strings of capacitor cells.
The design has an important synergy with Saft’s manufacturing capabilities since the construction is similar to that used in nickel-cadmium (Ni-Cd) cells, so ESMA’s supercapacitors can be manufactured on existing Saft production lines.
Since a supercapacitor stores energy electrostatically, with no physical changes taking place, it can have a service life of a million or more charge/discharge cycles, with no maintenance required. Furthermore, the performance of a supercapacitor remains stable over a very wide temperature range (typically -40 °C to +70 °C).
This makes them ideally suited for providing cranking power for starting the engines of heavy vehicles at very low temperatures, especially when fitted to vehicle fleets that need to start and stop their engines many times during a shift. Supercapacitors can also be applied in numerous other applications for peak power and energy storage.
There are also currently a number of investigations underway in pairing supercapacitor and battery technology in energy storage systems for hybrid and electric drive vehicles.
There could be significant performance gains and extended battery pack life duration with the proper capacitor-battery combination.
Stop-start, cold weather start, quick accelleration and braking power recouperation fonctions are very (too) demanding on the battery pack.
Wonder why Toyota, Honda, Ford and others with HEVs and PHEVs have not done it already?
Posted by: HarveyD | 11 May 2009 at 11:54 AM
I would say that it is the cost factor, for a car the extra cost might be prohibitive. If you extend battery life 20% but it doubles the cost, it is not a bargain.
In trucks and buses with huge surge currents and lots of stop and go usage, the caps make sense. It can probably double the life of the batteries.
Posted by: SJC | 11 May 2009 at 12:41 PM
No, it's not so much a cost factor. It takes 107Wh to accelerate a 2000 lb vehicle from 0 - 60mph. That's not enough to cover everything you want to do, but it takes a lot of wear and tear off the battery and solves a lot of performance issues. You get the point.
That's only about 10-20 cells depending on who's super cap technology you're talking about and adding another $1000-$2000 to a $20,000 battery pack is not that huge of a deal. It allows you to greatly extend the battery life and get more energy back from regen braking, etc.
The problem is the power control hardware/software. Most of them are not ready yet to deal with the compexity of the multiple sources and all the different conditions you have to account for.
How much do you pull from the super caps when you accelerate? How do you allow for the changing voltage since they change voltage as they drop energy content. How much do you put back into them as you charge them from a range extender, etc and how much spare capacity do you allow for regen braking when you're driving along? When you regen, do how much goes to the super caps and how much to the batteries? At what rates? How do you get the controller to deal with two sources with different power outputs(and inputs) and one device changes voltages while the other stays constant. And the problems go on and on.
They are all very solvable, but it takes a lot of trials and work to optimize these things and guess what? One size does not fit all so you have to tailor it to the expected driving conditions of the vehicle you're making.
We worked with a few of the battery makers and the super cap makers when we were designing the car that we want to produce. It's something they all want to do, but they're not there yet.
There was an announcement about a month ago on here that everyone pretty much ignored about a company who had integrated the electronics to allow you to work with all these different storage devices. I can tell that we're still very immature as an industry and even as a bunch of "green followers" because it didn't even get any comments and yet it is one of the most critical things going on right now.
The guys who really know how to design and test these power systems are going to be REALLY in demand soon...if they're not already.
Posted by: DaveD | 11 May 2009 at 06:56 PM
DaveD:
How much do you pull from the super caps when you accelerate? How do you allow for the changing voltage since they change voltage as they drop energy content. How much do you put back into them as you charge them from a range extender, etc and how much spare capacity do you allow for regen braking when you're driving along? When you regen, do how much goes to the super caps and how much to the batteries?
I would take the simple control strategy. Since the supercapacitors are mainly for providing the extra boost for acceleration and absorb the regenerative braking power, I would let the vehicle speed determine the charge state of the supercaps. So at 0 km/h they are full and at 120 (or 140 or whatever) km/h they are empty.
Posted by: Arne | 12 May 2009 at 02:18 AM
Controling the charge-discharge rates of the supercaps is certainly a must but it is not an impossible task.
Electronic control systems can be designed to do just that and very efficiently.
The ideal would be a lower cost, much higher performance, very quick charge, long lasting battery.
Since the technology will not be there for another 10 to 20 years, a combination super-caps + high energy density lithium batteries (like the 330-450 Wh/Kg Electrovaya) could be one of the best short to mid-term solution for extended range, extended life, BEVs.
Posted by: HarveyD | 12 May 2009 at 06:56 AM
"..why Toyota, Honda, Ford and others with HEVs...
This was the original question, so here is my guess. HEVs now use NiMH batteries in small quantities. They are lower cost and can charge and discharge quickly, so they do not need them.
Posted by: SJC | 12 May 2009 at 07:47 AM
SJC:
I heard that current Toyota-Ford NiMH equipped HEVs can only recouperate 30% to 40% of the braking energy and that SuperCaps could recouperate 2X to 2.5X more. If so, a Prius III equipped with SuperCaps could get up to 60 miles/gal in city travel. That could be important to many, specially taxis.
Posted by: HarveyD | 12 May 2009 at 03:02 PM
The batteries cost maybe $2000 and now add $2000 for supercapacitors. Again, it comes down to cost. Regenerative braking only provides 5% of the fuel savings so adding 3% fuel savings for another $4000 end user price may not be what people are looking for.
Posted by: SJC | 12 May 2009 at 03:40 PM
sjc it will be very intresting to share some tech information with u , do you have a blog ? twiter account?
Posted by: sm | 13 May 2009 at 02:47 AM
Nope, I do not even know what a blog or a twitter is.
Posted by: SJC | 13 May 2009 at 07:29 AM
SJC:
If rgenerative braking only recouperates 5% fuel savings, why is it that vehicles without it, take a 25% to 40% reduction in mpg in city driving and many hybrids so equipped don't, and even to better in city driving than on highways?
I know that there are other factors such as stop-start but isn't regenerative braking one the main one?
Posted by: HarveyD | 14 May 2009 at 02:31 PM
Regen-braking makes best out of the slow/fast,slow/fast traffic patterns that is typical in city and urban traffic areas. This is not stopping and idling as such but is still straining car and truck motors using more fuel. This is highly dependent on driver behavior but still out does fuel use on highway cruising cars. Hope this helps SJC.
Posted by: tunafin | 28 May 2009 at 03:01 AM
Regen-braking makes best out of the slow/fast,slow/fast traffic patterns that is typical in city and urban traffic areas. This is not stopping and idling as such but is still straining car and truck motors using more fuel. This is highly dependent on driver behavior but still out does fuel use on highway cruising cars. Hope this helps SJC.
Posted by: tunafin | 28 May 2009 at 03:01 AM