Electricnick, The EV Revolution

The world of battery is evolving every day as the push for electric vehicles, EV and other fuel efficient cars demand ever more powerful storage solutions.

Lead Acid Batteries. Innovations with the lead acid battery fell to wayside in the mid-70s.  However everything changed when consumer became more environmentally conscious and car batteries were found to be too heavy to made a car run on electricity alone.  This jump started another round of research to improve lead acid battery performance with new materials and technologies developed previously.

Lead Acid Battery Key Players. According to John Peterson at Seeking Alpha, Firefly Energy, Axion Power International and Australia’s Commonwealth Scientific and Industrial Research Organisation have been key players in the lead acid battery world.

The Firefly project was to use a carbon foam composite to replace lead current collector grids.  By reducing the amount of lead used in a battery, minimize lead that was not chemically active and improve energy density, as well as address the weight issue.  Their new Oasis battery should offer a 40% to 50% increase in energy density, higher power and up to 800 cycles at an 80% depth of discharge.  It should cost twice as much as a normal lead-acid battery, while offering 4 times the performance.

The Axion has worked on creating a hybrid between a lead-acid battery and a supercapacitor by replacing the lead-based negative electrodes with carbon electrode assemblies.  This is something we are especially interested here at electricnick, as these types of solutions offer some serious advances for electric vehicles, EV.  By eliminating much of the lead used and sulfates in a battery, while combining an ultracapacitor, you get the best of both world, sustained energy for the regular battery, and short bursts of energy with the ultracapacitator.

Axion’s PbC battery should offer a 400% increase in power and well over 1,200 cycles at a 90% depth of discharge.  It should cost twice as much as a normal lead-acid battery, while ofering 6 to 8 times the performance.

CSIRO has also been working on an ultrabattery that sports impressive results.  In a 100,000 mile test on a Honda Insight, the CSIRO ultrabattery got 2.8% less gas mileage because of the added battery weight; but offered a $2,000 cost savings over the factory original NiMH battery.

NiCAD & NiHM. The next advance in battery technology came through NiCad (nickel-cadmium) batteries.  Originally used for small devices, they hold more energy per pound than lead-acid batteries, and go through several hundreds of charge/discharge cycles.  Their downside is that they have a “memory effect”.  They loose their power-holding capacity if they aren’t fully discharged before being recharged.

Another big breakthrough was NiMH (nickel-metal hydride) batteries that were first tried in electric vehicles, EV.  General Motors famous EV-1 used NiMH batteries wit a range of 140 miles.  Southern California Edison drove 7 million miles on 320 electric Toyota RAV4’s, and concluded NiMH batteries could last 130,000 to 150,000 miles.

Ovonics, part of Energy Conversion Devices, which GM bought 60% of ECD, and then in 2000 Texaco bought GM’s share of ECD, and in a 50/50 partnership with ECD, created a spinoff battery company called Cobasys, which owns the patent to NiMH technology… is your head spinning?  No, continue.  Shortly thereafter, Texaco was acquired by Chevron.  And that explains the intricate dance between oil companies and battery research.

Lithium And Other Advances.

Lihtium-ion a la Sony.  When Sony came out with its original Li-ion batteries, they had densities of around 200 Wh/kg, and could deliver energy in an hour, while sustain 500 to 1,000 cycles.  Higher-end Li-phosphate and Li-titanate batteries offer less energy density at around 100 Wh/kg, while their energy be delivered in around 5 minutes but with 5,000 to 20,000 cycles.

With no standardized reporting metrics, precise comparisons are almost impossible.  However, we can conclude that lithium-cobalt batteries cost anywhere from $0.45 to $0.55 per Wh.  High-end Li-phosphate and Li-titanate batteries can cost upwards of $1.50 per Wh. About the only good price news in the group is Li-polymer batteries that cost about $0.35 per Wh.

Favorite quotes found when researching:

“After all, we Americans have never minded lugging around a few extra pounds if the heavier choice is 40% to 80% cheaper.” by John Peterson

“When your only policy is a hammer, everything looks like a nail”.  Sorry, the owner to this brilliant one escapes us.

Other resources:

Wikipedia’s electric battery, Lithium-ion battery, Ultra or Supercapacitators.