Sony Offers New, Improved Lithium-Ion Battery

(Note: Before you get too excited, it should be noted that Sony's improved battery is for motor-driven devices, not EV's)

Sony announced an improved lithium-ion battery. This battery offers a lifespan four times greater than current lithium-ion batteries, possessing a retention capacity of 80% after 2,000 charge-discharge cycles (link).

Without getting too technical about the whole thing, the new battery uses as its cathode material olivine-type lithium iron phosphate, which Sony says is ideal for the job "due to its robust crystal structure and stable performance, even at high temperatures."

The material also apparently contributes to the battery's faster charging time--it can hit 99 percent of its full capacity in 30 minutes (approximately half the charge time of Sony's current lithium ion battery line, which mainly use cobalt oxide-based cathodes).

For the moment, the batteries will just be showing up in motor-driven devices like power tools--so if you own a cordless band saw, you're in luck. Those of us who just need to worry about powering our iPods and laptops, however, will have to wait a little while.

- Brewskie

Proglonged Lithium-ion Battery Life Hangs by the Nanowire

A look at nanotechnology is touching lithium-ion batteries:

A new type of nanowire electrode developed by materials science and engineering professor Yi Cui at Stanford is a step toward that goal.

The new electrodes, discussed in last week's Nano Letters, can store six times as much charge as the graphite electrodes in current lithium batteries--that means electric cars that give more mileage per charging session.

When a lithium battery is charged, lithium ions move from the positive electrode (cathode) to the negative anode. Silicon is a promising material for anodes because it can store over 10 times as many ions as graphite at the same weight. But when silicon absorbs charge, it swells to four times its original volume, cracking after a few charging cycles.

The new nanowires exploit the properties of silicon and graphite. Cui and his colleagues make the material by depositing amorphous silicon on carbon nanowires. The wires can store a charge of about 2,000 milliamp hours per gram, while graphite anodes store less than 360 milliamp hours per gram. Meanwhile, the carbon core makes them robust. "Lithium ions can also get absorbed into carbon," says Cui, "but the volume expansion of carbon is 10 percent or smaller, so it provides a stable backbone." In tests, the nanowires performed well for more than 50 charging cycles.

- Brewskie

This EV Battery Will Outlast Your Dog

This article is from several weeks back, but it's worth noting. Read by clicking here and find out how long this bad boy lasted in a two-year test run:

When it comes to electric vehicles, critics have referred time and again to the fact that the death and replacement of batteries nullifies any savings made at the pump. With a battery’s limited lifespan, and battery prices still high, drivers may not be saving much. However, recent tests by battery provider Southern California Edison (SCE) show.

Over the past two and a half years, SCE has been testing a lithium-ion battery sub-pack. And the results are incredible. The lithium-ion battery has displayed remarkable longevity, surviving 180, 000 miles with no significant deterioration. With the average family vehicle traveling less than 15,000 miles per year, this test holds great significance. This dramatic increase in the life expectancy of an EV battery pulls the cost equation more convincingly on the EV’s side.

[...]

The battery, a Johnson Control-Saft lithium-ion battery subpack, was tested in a commercial delivery van in a laboratory setting at SCE’s Electric Vehicle Testing Center in Pomona, CA. The battery subpack is one sixth of the actual battery size used in a plug-in hybrid electric vehicle.With such remarkable test results, and testing still in progress on the subpack, the U.S. Department of Energy has asked SCE to test the battery’s viability for passenger car performance.

The Department of Energy supplied a full sized battery for further testing.

This will be one of the posts I will refer to when I (eventually - depends on the schedule) get around to doing a future post currently in mind: Why Electric Car Critics are Dead Wrong. Gotta roast Simmons again, though.

- Brewskie