can anyone tell me what type of battery is most likely to be used on electric vehicles in the future and where could I find a reference source for this, any help would be greatly appreciated.

Let's see, wher'd I put my crystal ball....

The path ahead is not clear, to be more exact there are many paths, and it is impossible right now to know which ones will ultimately be successful.
In general variations on Lithium are the front runners. In far left field is EEStor with its mythical super capacitors that can store several times more power than to-days batteries. This is the only non-lithium possibility I know of.

Lithium-Air batteries have the highest energy to weight, but no-body so far has figured out how to make these re-chargeable. Theoretically you might get 1000 miles out of one of these, but then you have to throw it away when discharged. There are several companies and universities working on variants trying to solve this issue including IBM, AIST http://newenergyandfuel.com/http:/newenergyandfuel/com/2009/08/06/a-battery-so-good-and-its-real/
University of St Andrews, UK
http://gow.epsrc.ac.uk/ViewGrant.aspx?GrantRef=EP/E03649X/1

I think the most likely winner will be Dr. Nazar's Lithium-Sulfur battery,
Lithium-Sulfur has long been considered the second most energetic variation next to lithium-air, and again the problem has been how to make it re-chargeable. Lynda Nazar has solved that problem.
http://www.nserc-crsng.gc.ca/Media-Media/NewsbulletinStory-ArticleAnterieur_eng.asp?Id=1026

There have been several breakthroughs in making the currently best type, Lithium-polymer-manganese as used in the Volt, much better see Yi Cui's silicon nanowire discovery http://news-service.stanford.edu/news/2008/january9/nanowire-010908.html
There are several variants on his discovery such as http://www.today.colostate.edu/story.aspx?id=2849
and
http://www.greencarcongress.com/2008/11/3d-porous-silic.html

For more information on the best state-of-the-art Li-poly-manganese see http://www.electrovaya.com/products/master/Default.aspx

There are a great number of others claiming to have made breakthroughs although I don't believe any are better than the preceding ones. In no particular order:
http://www.amprius.com/
http://www.superlatticepower.com/20080602/
http://esciencenews.com/articles/2009/03/11/mit.battery.material.could.lead.rapid.recharging.m any.devices
http://www.sionpower.com/
http://web.mit.edu/newsoffice/2006/batt-side.html
http://www.seeo.com/
http://www.greencarcongress.com/2009/10/koller-20091029.html#more
http://www.revolttechnology.com/
http://web.mit.edu/newsoffice/2006/virus-battery.html
http://www.a123systems.com/
http://www.altairnano.com/profiles/investor/fullpage.asp?f=1&BzID=546&to=cp&Nav=0&LangID=1&s=0&ID=10724
http://www.ecolocap.com/site/en/mbt-cnt-battery.html

What happens to batteries when these two ideas are combined?

Amprius - anode;

In the 18 months since Amprius was founded, researchers at the company have built on Cui's research and have demonstrated that the silicon anodes can be used in practical batteries. Silicon nanowires, which are vertically arrayed and tethered but flexible, are used to make the battery anodes.

As the nanowires take in lithium, they can swell and bend to accommodate it, without breaking. However, this isn't mechanically stable enough. Amprius has addressed this problem by giving the nanowires a thin, reinforcing metal core that the company likens to rebar (the steel strut used to reinforce concrete structures). This "rebar" prevents the anode from expanding and contracting too much. In testing, the silicon anodes can store three times more energy than carbon anodes by weight.





Envia - cathode;


A California company called Envia Systems is developing a battery that promises to store twice the energy of lithium-ion batteries—the kind typically used in electric cars.

Envia has received investment from General Motors, which could be one of the biggest buyers of lithium-ion batteries for cars in coming years thanks to a planned lineup of plug-in cars including the Chevy Volt. The automaker's venture capital arm, GM Ventures, announced a $7 million investment in the startup last month.

Envia has also begun working on more higher energy density anodes, with a $4 million grant from the U.S. Department of Energy's Advanced Research Projects Agency-Energy. Last year, in partnership with Argonne, Envia set out to develop silicon-carbon nanocomposite anodes with the idea of integrating them with high-capacity cathodes, and devising processes for scaling up production to high volumes.



And ultracaps


Researchers at Nanotek Instruments in Dayton, Ohio, have now made graphene electrodes that could lead to ultracapacitors with more than five times the energy density of commercial devices. By using graphene--atom-thick sheets of carbon--Nanotek increases the surface area of the electrodes in the ultracapacitors, boosting the amount of charge that they can store.


Dileep Agnihotri, the CEO of Graphene Energy, a graphene ultracapacitor startup based in Austin, Texas, says that his company has achieved similar energy densities with a better cycle life. Its cells lose 3 percent of their charge storage after 10,000 cycles. "We are in the range of lead-acid batteries with a charge-discharge every second," he says.


batteries are typically operated in the middle range of their full charge cycle, often using only about 20-50 percent of their total charge capacity, says Joel Schindall, an MIT electrical engineering and computer science professor. This means that an ultracapacitor with about 20 percent of the energy density of a rechargeable battery, but with a rapid recharge time and almost unlimited lifetime should be competitive for some electric vehicles.


Meanwhile, FastCAP Systems, a spinoff based on technology developed at Schindall's lab, is making ultracapacitor electrodes with vertically grown arrays of carbon nanotubes. Schindall says the company has already achieved energy densities of 20 to 25 watt-hours per kilogram. The target is 25 to 30, and it should be at least two years before FastCAP can deliver a market-ready product.

From artcles on energy by Technology Review magazine.

I'm still crossing my fingers for EEscam. Not.