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Electric-vehicle shortfalls may be solved by Hydro-Quebec battery invention

The electricity provider says it is developing a device that could outlast any car and be recharged in minutes with a fast-charging unit.

  • fast-charging

Quietly, Hydro-Quebec’s research arm is aiming for a battery revolution.

The electricity provider says it is developing a device that could outlast any car and be recharged in minutes with a fast-charging unit.

On the other hand, it would propel vehicles about one-third less distance between charges than current lithium-ion batteries.

In effect, this battery represents a new approach to range anxiety, requiring more frequent charges but accomplishing them in slightly more time than it takes to gas up a conventional car.

“Performance, service life and, most important, safety, are issues that continue to plague the development of the (lithium-ion) battery for the mass market,” states Karim Zaghib in a recent Journal of Power Sources, on behalf of his colleagues at the Institut de Recherche d’Hydro-Québec and others from universities in Paris. “We report … a battery that fulfills these requirements.”

Hydro-Québec, which has been involved in battery research for 30 years, has several partners in the project and a licensing agreement with Massachusetts-based A123 Systems, which supplies General Motors.

Although most lithium-ion batteries last only several hundred cycles of depletion and recharging, Zaghib says this one would survive 20,000: If recharged daily, that’s a 50-year lifespan.

A major catch is the cost of the fast-charging system, also known as Level Three.

(Level One means plugging into a 120-volt household socket. Level Two operates at 240 volts: This type, which costs $1,000 to $2,000 to install and replenishes batteries overnight, is becoming the standard for home charging.)

Level Three chargers are commercial-scale units that cost at least $15,000. A publicly accessible network would be required for Hydro’s battery to succeed.

The battery itself is another invention that screams the question: How do they figure this stuff out?

Each of the hundreds of cells in a battery contains two electrodes — the cathode has a positive charge, the anode is negative. Lithium ions flow between them in a liquid called electrolyte. The flow in one direction charges the battery; the other discharges.

On each trip, the ions pass through a separator, a piece of material that keeps the electrodes from touching and causing a short circuit. In most lithium batteries, the cathode is coated with a substance called lithium cobalt oxide, which is toxic and expensive.

Like many other new versions, Hydro’s employs a compound based on lithium, iron and phosphate. The ingredients must be heated, then, cooled, at precise temperatures and times.

This forms little ingots, which must be ground and milled with equal precision. The smaller the particles, the more power they supply; but too tiny, they’re hard to handle and lose energy-storage capacity.

Conventional electrode materials expand and contract as the lithium ions enter and leave: Before long, they crack and disintegrate. Zaghib and his colleagues devised a structure with particles so small it won’t change size: It means that a battery will be guaranteed for the life of the car.

For the anode, the researchers chose the impressive-sounding Li4Ti5O12, processed similar to the cathode material. This compound replaces graphite, which is heavy and, during fast charging, reacts with lithium ions to create a coating that cuts performance.

Even with its reduced range, the battery is “still more than needed for many daily uses,” and its benefits outshine any inconvenience, the researchers say.

They claim a car with this battery and a 200-kilometre range could be recharged in five minutes. So far, they’ve achieved that time only in a lightweight test car with a 32-km range and top speed of 64.

Still, it’s impressive work and holds promise of better days for EVs.

peter.gorrie@sympatico.ca

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