Recharging Vehicles: Japan demo shows electricity entering EV through tires

Electric vehicles' future continues to tease scientists to devise promising and practical ideas to keep these cars moving along the highways without having to pull over and wait for a battery recharge.

Solutions for the so called “charging and range problem” took yet another twist this month when a Japanese university team demonstrated how electricity can be transmitted to a pair of tires through a four-inch-thick block of concrete, the type of concrete used on some roads. 

The team took its demo to WTP (Wireless Technology Park) 2012, a trade show on wireless technologies, earlier this month in Yokohama.

 

Their solution is in the form of a wireless power prototype that can successfully transmit electricity through the concrete block. They consider the prototype as an early step to improve on, and that such an approach can be used one day to keep electric vehicles on the move.

Takashi Ohira, an electrical engineering professor at the Toyohashi University of Technology, who leads the team, has developed his electric field coupling system to supply a charge to a car through its tires. The goal is to enable power transmission as the vehicle’s tires travel along the road with suitable efficiency and power transfers.

In the demo, a metal plate was placed along with a four-inch layer of concrete, representing the road surface. Electricity between 50 and 60 watts was transmitted to actual-size automobile tires. The demo also showed a light bulb, attached between the two demo car tires, turning on.

The university team’s project is called EVER (Electric Vehicle on Electrified Roadway). The focus is research aimed at using wireless power transmission technologies based on electric field coupling for transmitting power to a running vehicle.

The July demo is the latest of similar past efforts by the researchers. Last year, Toyota Central R&D Labs and Ohira reported on their work to allow electric cars to drive unlimited distances on an electrified roadway.

They reported a system that similarly transmits electric power through steel belts inside the two tires and a metal plate in the road.

They presented their work at a workshop in Kyoto. To test how much energy would be lost as electricity traveled through the tire rubber, the researchers also set up a lab experiment with metal plates.

"Less than 20 percent of the transmitted power is dissipated in the circuit," said Ohira at that time. With enough power the system could run typical passenger cars, he added.

To make their present technology useful, the electric power needs to be increased by 100 times. But, moving ahead, the group said that they are up to the task of meeting the project's challenges.

Car Batteries That Can Multitask

THERE’S more than meets the eye in the battery-powered model car sitting in Emile Greenhalgh’s laboratory at Imperial College London.

The model has been modified by the researcher’s team to increase the amount of electrical energy it can store — but not by installing a bigger battery. Instead, the team added body components that double as capacitors, devices that hold an electrical charge until they are tapped.

“Although the energies they provide are fairly modest,” Dr. Greenhalgh, a composites expert, said, “they have shown that our material could be used to smooth the demands on the battery, thus enhancing its life.”

Designers of full-scale electric vehicles are working toward the same goal: battery reserves need to be extended because today’s technology typically delivers only enough power for about 100 miles of driving.

Larger batteries are not necessarily the solution, either. Even the most advanced designs weigh hundreds of pounds, reducing the vehicle’s range.

To help cut weight and increase driving distances, engineers are developing car frames and bodies made of carbon fibre-reinforced composites, plastic materials that can be 50 percent lighter than steel but provide superior strength and rigidity. Although used in a handful of exotic sports cars, carbon composites remain too costly for mass-market cars.

One potential solution is to build autos with carbon composites that can also serve as batteries. The dual-function materials could make E.V.’s and hybrid vehicles lighter as they simultaneously provide extra electricity.

“Structural power technology combines mechanical structure and energy storage capabilities,” said Dr. Greenhalgh, who heads a group at the college working on the concept. “This could allow us to have our cake and eat it too.”

To enable the composite materials to store electricity, the resin that binds the carbon fibres is laced with lithium ions; the fibres serve as conductive electrodes for this type of charge-holding capacitor.

It is different from a battery, which produces electricity from a chemical reaction. Another research group, at the Swedish Institute of Composites, is working on a structural battery.

Dr. Greenhalgh also leads a wider European Union project, which includes Volvo Cars, to study the innovative materials. “Volvo says that structural power technology will be key to the E.V.’s they’re developing,” he said.

Redox-Flow batteries to power 2,000 households

Above is a schematic of a redox-flow cell detailing the technology.

The energy storage units operate in conjunction with an electrolyte tank for each of the two electrodes.

The liquid electrolytes (e.g., vanadium) contain metal ions that flow through electrodes made of porous graphite fleece, separated by a membrane which is proton-permeable.

During this exchange of charge a current flows over the electrodes which can be utilised.

The battery can provide unlimited capacity simply by using larger and larger storage tanks, and it can be left completely discharged for long periods with no ill effects. And because both electrolytes contain the same materials they do not contaminate the cells and the tanks if the electrolytes become mixed. They only need to differ in terms of ion charge or oxidation stage.

“This makes it possible to build very robust and durable batteries – a decisive advantage of this battery technology,” emphasizes Fraunhofer’s Dr. Tom Smolinka.

On the downside, redox flow battery technology has relatively poor energy-to-volume ratio, and the system is more complex than standard storage batteries. For instance, insuring that the vanadium fluid flows smoothly through the large membranes and past the felt-like carbon electrodes in the cells themselves is a challenge, according to the researchers.

Fraunhofer researchers are convinced that the advantages of redox flow batteries will drive development, and in the next five years larger demo systems will be built and quickly followed by commercial redox-flow batteries.

Eventually, the focus will move on to the development of redox-flow batteries as a feasible technology for electric cars.


Giant futuristic batteries to power 2,000 households | ZDNet

Volvo 660-Pound Auto Battery Crash Test

What happens when a 660-pound electric car battery hits an offset wall while traveling at 40 mph?

Without a conventional engine under the hood, and with 660 pounds of extra weight in the back and center, Volvo engineers had to rethink the way they designed the C30 Electric.

They had to add some extra reinforcement to the front end crumple zones. Which they did, before crash testing the car:

"The test produced exactly the results we expected," Jan Ivarsson, Volvo safety senior manager, said in a statement. "The C30 Electric offers the very same high safety level as a C30 with a combustion engine. The front deformed and distributed the crash energy as we expected. Both the batteries and the cables that are part of the electric system remained entirely intact after the collision."

The successful test doesn't mean Volvo is going to jump on the EV bandwagon immediately. Other car manufacturers e.g. Chevy and Nissan, have their Volt and Leaf respectively, heading into consumer hands relatively soon, but Volvo's plans for a demo fleet of it's C30, will be delayed until later in 2011.

Reisman, Bowen Complete First STS-132 Spacewalk

Reisman, Bowen Complete First STS-132 Spacewalk

Astronauts Garrett Reisman and Steve Bowen completed a seven hour, 25 minute spacewalk at 3:19 p.m. EDT.

The new space-to-ground antenna they installed will increase the space station's ability to conduct two-way data, voice, and video communications.

They put into place a new tool platform for the Dextre robot, and Bowen prepared six batteries that will be installed during the second and third spacewalks by loosening the bolts that hold the batteries in place. The batteries weigh approximately 2,200 pounds.

Meanwhile, the space shuttle's robotic arm has successfully grappled the Mini Research Module-1 for relocation to the space station on flight day 5. It will provide additional storage space and a new docking port for Russian spacecraft.

This was the first of three STS-132 spacewalks, 237th conducted by U.S. astronauts, the second for Reisman and the fourth for Bowen. It was the 144th in support of International Space Station assembly and maintenance, totaling 900 hours, 58 minutes. First Spacewalk of STS-132 Complete

Mission Specialists Garrett Reisman and Stephen Bowen completed the first spacewalk of the STS-132 mission at 3:19 p.m. EDT. They installed a second station space-to-ground Ku-band antenna and a spare parts platform on Dextre, the two-armed robotic Special Purpose Dexterous Manipulator. The spacewalk lasted 7 hours, 25 minutes.