Driving Home The Future

New battery technology for automobiles offers hope for consumers worldwide, especially with energy concerns arising from the revolution in Libya and the earthquake-tsunami in Japan.

Though better batteries are emerging as alternatives to fossil fuels, the weight and size of the batteries remain issues. Car manufacturers and scientists are developing new polymeric composites to reduce weight and free space.

The composites carry structural loads and store electrochemical energy. New electrode and electrolyte materials are being synthesized to optimize these properties.

To date, research continues on the development of solvent-free structural polymer electrolytes based on vinyl ester resins, along with carbon nanotubes. These materials exhibit a combination of strength and ion conductivity.

Using new resin electrolytes, the components are being integrated using moldable, scalable, and cost-effective processing techniques.

Cheaper Carbon Composites?

Carbon composites, extremely strong and light, are used in products ranging from tennis racquets to aircraft wings. Even some exotic cars are built with this material, but it is generally too expensive for mass-produced vehicles.

With the ability to store energy, carbon composites could become a lot more attractive for the automotive industry, according to Emile Greenhalgh of Imperial College, London.

Greenhalgh is leading the research as part of a broader European Union project studying the incorporation of different battery materials into the bodywork of cars.

The study encompasses academic and industrial partners, including the British Ministry of Defense, and Volvo (owned by Ford). The military is interested in extending the range of robotic drones and other light-weight applications.

How It Works

Greenhalgh’s material consists of woven sheets of carbon fibers which are made rigid using a resin.

To enable the material to store electrical energy, two layers of woven fibers are made into a sandwich, separated by a thin layer of a glass-based insulating material.


The resin with the carbon layers is laced with lithium ions to collect in one layer when a voltage is applied. The current flows when the sandwich is placed in a circuit. All of this is encapsulated with further layers to ensure it’s electrically isolated.

The composite behaves more like a capacitor or supercapacitor than like a battery, according to Greenhalgh.

Batteries are good at storing large amounts of charge but slow at delivering it. For capacitors, the reverse is true.


Supercapacitors have a large internal surface area which allows a large amount of energy to be delivered rapidly.

These may be used in some electric cars to provide a short burst of power for rapid acceleration. In hybrids, supercapacitors are used to recover power during braking.

To get similar characteristics from composites, the carbon fibers are first chemically treated with an alkali to create tiny pits on their surface.

This dramatically increases their surface area and the amount of charge they can hold without impairing the physical strength of the material.

Conflicting Resin Needs

Another challenge lies in resolving the two conflicting requirements of the resin.

“You want it very rigid and stiff, but from an electrical point of view you also want it to allow ions to flow through the material,” Greenhalgh says, noting with traditional resins you typically get one or the other.

Greenhalgh’s solution uses a polymer gel-based resin which combines two networks of cross-linking structure. One holds the material together and the other provides a conduit for the charged particles.

If the electrical storage composites can be boosted close to that of lithium-ion batteries, then only the roof, the bonnet and the boot lid are needed to power an electric vehicle for 130 km, according to inventor Per-Ivar Sellegren.

Sellegren, a Volvo senior engineer, is credited with the company's cutting-edge body panel battery technology.

Extended Power Factors

The composites also can be used to reduce the amount of wiring in vehicles, Greenhalgh says. The rear lights could then be powered by this material.

Compared with most rechargeable batteries, super-capacitors tend to have longer working life.

That’s an obvious benefit since most drivers of electric cars have not had their vehicles long enough to incur thousands of dollars to replace worn-out batteries.

From WMB’s vantage point, if you drive an electric car, you shouldn’t have to pay higher maintenance costs to reduce your carbon footprint.

TechMan

Electric Cars May Move Us

With the continuing oil disaster in the Gulf of Mexico, many may wonder if we can wean ourselves off of fossil fuel. Part of the solution obviously resides in green technology and certainly electric vehicles are driving interest as a probable alternative to gasoline powered cars.

Three companies – General Motors, Nissan and Toyota – are gaining traction in the marketplace. GM’s Chevrolet Volt is able to travel up to 40 miles on a single battery charge through a conventional household outlet. This automobile is scheduled for sale to consumers later this year. Nissan is touting a car called the Leaf (top) that has a projected range of up to 100 miles. And Toyota has a plug-in version of the Prius which is nearing public announcement.

These cars may not even require gasoline and can represent a dramatic cutback in exhaust emissions; it's the kind of automotive breakthrough that clean energy advocates have been trying to reach for decades.

The timing couldn’t be better since manufacturers have powerful advocates in government and industry. For instance, the Obama administration is offering generous subsidies to manufacturers which produce electric vehicles and consumers who purchase them. As a result, many automakers are gearing up for electric vehicle production, and venture capitalists are willing to invest in new designs.

Still, the big question is whether consumers will embrace electric vehicles in large enough numbers to make the whole dynamic work.

Gasoline is now less than $3.00 per gallon in most areas of the country. Initial electric-powered cars will cost much more than conventional technology vehicles, even with government subsidies. Current hybrids average about 30 mpg, but until gasoline prices increase significantly more, electric cars may have to wait for consumer attitudes to catch up.

Since electric cars run purely on electrical power, mile for mile these cars will operate at significantly lower costs, given current kilowatt power rates.

GM has designed the Volt (right) with a 40-mile range on a single charge with the capability to be recharged from a 120-volt household outlet. Once the battery runs low, a gasoline- powered motor engages and charges a generator which can result in another 300 miles of driving distance.

The electric Toyota Prius (left) has a range of about 10 to 15 miles and in a similar manner to the Volt, and the Prius can produce about 300 miles. But the Nissan Leaf is slated to be a “pure electric” car able to travel about 100 miles on a single charge. On the downside, the Leaf does not have a secondary power source and that may result in what the industry calls “range anxiety.”

The potential gasoline savings for the new technology is enormous. Currently, the Toyota Prius Hybrid gets about 50 mpg. On the other hand, GM’s Volt is projected to get about 230 mpg, and the Leaf would result in an equivalent 300 mpg. This is no match for conventional gasoline cars.

Electric vehicles vs. conventional cars

One example of a high-end electric vehicle is the Tesla Roadster. It consumes about 110 watt-hours per kilometer and is able to travel about 244 miles on a single charge. The full charge takes about 3.5 hours. Analysts estimate the Roadster ranges from 135 to 400 mpg, depending on how the equivalency between gasoline and electricity is computed. As a sidebar, it should be noted that the Telsa Roadster accelerates to 60 mph in 3.9 seconds; almost instant torque is available with electric cars.

GM Volt Product Manager Tony Posawatz (right) says 100 miles of battery-powered travel will require about $2.75 worth of electricity. This means up to 3 cents per mile based on average electricity rates of about 11 cents per kilowatt hour. If drivers charge their Volt overnight, when off-peak electricity rates are lower, the cost could be as little as 1 cent per mile. Posawatz says at these rates the annual cost-savings on fuel could easily be more than $1,000 for typical driving.

There are potential problems on the horizon with electric vehicles because they require entirely new sets of hardware and software.

Lithium-ion batteries have been used in cell phones and computers for years. However, there is still uncertainty surrounding scale-up and performance requirements. There also are the issues of disposal and repair. Electric car technology will require new training and infrastructure.

The initial cost of electric vehicles also is high, especially for early adapters. Most analysts predict that, at $3.00 per gallon, it takes nearly 15 years to amortize the initial investment. That’s why some manufacturers are willing to absorb some of this cost. Even with government rebates and incentives, many consumers may be reluctant to take the early risks associated with a product without a proven track record and resale history.

Still, the possible emergence of electric vehicles as a dominant product may be just one silver lining in the gulf oil crisis. There are obvious risks associated with fossil fuel drilling. Many lives are at risk and careers are in jeopardy as a result – just some of the lessons learned while BP and the U.S. government continue to grapple with the spreading spill from the exploded rig.

This environmental calamity, with its impact for years to come, may serve to put our lifestyle in perspective … how overly dependent we still are on fossil fuels. Cheaper and greener electric car technology may be the answer for consumers, now and in the future.

This post is from TechMan, WMB co-author who blogs about trends, issues and ideas affecting business, industry, technology and consumers.