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Batteries for phones and laptops could soon recharge ten times faster and hold a charge ten times larger than current technology allows.

Engineers at Northwestern University in the US have changed the materials in lithium-ion batteries to boost their abilities. One change involves poking millions of minuscule holes in the battery. Batteries built using the novel technique could be in the shops within five years, estimate the scientists.

A mobile phone battery built using the Northwestern techniques would charge from flat in 15 minutes and last a week before needing a recharge. The density and movement of lithium ions are key to the process. The recharging speed has been accelerated using a chemical oxidation process which drills small holes - just 20-40 nanometers wide - in the atom-thick sheets of graphene that batteries are made of. This helps lithium ions move and find a place to be stored much faster.

The downside is that the recharging and power gains fall off sharply after a battery has been charged about 150 times. "Even after 150 charges, which would be one year or more of operation, the battery is still five times more effective than lithium-ion batteries on the market today," said lead scientist Prof Harold Kung from the chemical and biological engineering department at Northwestern.

So far, the work done by the team has concentrated on making improvements to anodes - where the current flows into the batteries when they are providing power.The group now plans to study the cathode - where the current flows out - to make further improvements.

Chemists have solved the 150 year-old mystery of what gives the lead-acid battery, found under the hood of most cars, its unique ability to deliver a surge of current. Lead-acid batteries are able to deliver the very large currents needed to start a car engine because of the exceptionally high electrical conductivity of the battery anode material, lead dioxide. However, even though this type of battery was invented in 1859, up until now the fundamental reason for the high conductivity of lead dioxide has eluded scientists.

‘The unique ability of lead acid batteries to deliver surge currents in excess of 100 amps to turn over a starter motor in an automobile depends critically on the fact that the lead dioxide which stores the chemical energy in the battery anode has a very high electrical conductivity, thus allowing large current to be drawn on demand,’ said Professor Russ Egdell of Oxford University’s Department of Chemistry, an author of the paper. ‘However the origin of conductivity in lead oxide has remained a matter of controversy. Other oxides with the same structure, such as titanium dioxide, are electrical insulators.’

Through a combination of computational chemistry and neutron diffraction, the team has demonstrated that lead dioxide is intrinsically an insulator with a small electronic band gap, but invariably becomes electron rich due to the loss of oxygen from the lattice, causing the material to be transformed from an insulator into a metallic conductor.

The researchers believe these insights could open up new avenues for the selection of improved materials for modern battery technologies. Professor Egdell said: ‘The work demonstrates the power of combining predictive materials modelling with state-of-the-art experimental measurements.’

The five-year-old company today is expected to disclose technical details of its batteries which executives say could lead to cutting EV battery pack prices in half in three or four years. Envia Systems' batteries are being evaluated by a number of automakers, including its largest investor General Motors, according to CEO Atul Kapadia.

TheAntiDoomer wrote:Actually we are talking about a 300 mile range for around 20,000$.

TheAntiDoomer wrote:

The five-year-old company today is expected to disclose technical details of its batteries which executives say could lead to cutting EV battery pack prices in half in three or four years. Envia Systems' batteries are being evaluated by a number of automakers, including its largest investor General Motors, according to CEO Atul Kapadia.

NATIONAL HARBOR, Md.—A company founded in the Palo Alto public library has taken a dose of government money and technology and turned it into the most energy-dense battery ever. Envia System's new lithium-ion battery packs roughly twice as much energy per gram as present batteries, the company will announce here at the third annual summit of the Advanced Research Projects Agency—Energy (ARPA–e).

"We achieved 400 watt-hours per kilogram," explains materials scientist Sujeet Kumar, Envia co-founder and chief technology officer. "We have made a 40 ampere cell in a large format that automakers can recognize and use," and one that has been validated by independent energy density tests at the Naval Surface Warfare Center in Crane, Ind.

TheAntiDoomer wrote:Actually we are talking about a 300 mile range for around 20,000$.

Revi wrote:We use our small electric car every day. It cost around $5000, and it's made in the USA.

TheAntiDoomer wrote:New Energy-Dense Battery Could Enable Long-Distance Electric Cars

http://www.scientificamerican.com/artic ... ctric-cars

NATIONAL HARBOR, Md.—A company founded in the Palo Alto public library has taken a dose of government money and technology and turned it into the most energy-dense battery ever. Envia System's new lithium-ion battery packs roughly twice as much energy per gram as present batteries, the company will announce here at the third annual summit of the Advanced Research Projects Agency—Energy (ARPA–e).

"We achieved 400 watt-hours per kilogram," explains materials scientist Sujeet Kumar, Envia co-founder and chief technology officer. "We have made a 40 ampere cell in a large format that automakers can recognize and use," and one that has been validated by independent energy density tests at the Naval Surface Warfare Center in Crane, Ind.

ian807 wrote:There's about 7 gallons worth in a cubic foot, or about 924 megajoules per cubic foot.