Modern Lead Battery Systems
(BU6A)
With the efforts of going green, there is renewed interest in finding new battery systems for wheeled mobility and automotive applications to lower our dependency of hydrocarbon. This page summarizes the work done with lead-based chemistries.
When compiling data of new battery system, the battery inventors are leaning towards publishing the positive attributes and the negatives are kept under wraps. This is why much hyped systems that show great potential on paper do not always make it to commercial applications but quietly die.
Firefly Energy
The composite plate material of the Firefly Energy battery is based on a lead acid system that is lighter, longer living and has higher active material utilization than current lead acid systems. The first battery reaching the market will include foam electrodes for the negative plates. The performance is comparable to NiMH with possible lower manufacturing costs. A design concern is microtubule blockage caused by PbSO4 crystal growth that will be dominant during low discharge conditions. In addition, crystal expansion could cause surface area reduction. Firefly Energy is a spin-off of Caterpillar.
Axion Power
The Axion Power e3 Supercell is a hybrid battery/ultracapacitor in which the positive electrode is standard lead dioxide and the negative electrode is activated carbon. The assembly process is similar to lead acid. The Axion Power battery is aimed at the hybrid car market and the company claims faster recharge times and longer cycle life on deep discharge than with customary lead acid systems. Specifications show a low power density of 12Wh/kg.
Altraverda
Like Firefly Energy, the Altraverda battery is based on lead acid, using a proprietary titanium sub-oxide ceramic structure [Ebonex] for the grid, and AGM separators. The un-pasted plate contains Ebonex particles in a polymer matrix with a thin lead alloy foil on the external surfaces. The energy density is 50-60Wh/kg. Based in the UK, Altraverda is working with East Penn in the USA, Exide in India and Vladar Enterprise in the Ukraine.
CSIRO Ultrabattery
The CSIRO Ultrabattery combines an asymmetric ultracapacitor and a lead acid battery in each cell. The capacitor enhances the power and lifetime of the battery by acting as a buffer during charging and discharging. The technology has been licensed to Furukawa Battery. The lifetime is 4 times longer than customary lead acid systems and produces 50% more power. It is also 70% cheaper to make than current hybrid electric vehicle (HEV) batteries. CSIRO batteries are undergoing road trials in a Honda Insight HEV and show good results.
EEStor
This is the mystery battery/ultracapacitor that receives much media attention. The battery is based on modified barium titanate ceramic powder. EEStor claims that the battery has a specific energy of up to 280Wh/kg. The company is very secretive about their invention and only limited information is available. Financial Post, 26 June 2008 compares EEStor with specifications of NiMH and customary lead acid systems.
| |
EEStor |
NiMH Hybrid |
Lead Acid, Gel |
| Weight (lbs) |
300 |
1,700 |
3,600 |
| Self-discharge rate/30 days |
0.02% |
5% |
1% |
| Charge time 100% SoC |
3-6 minutes |
>3H |
3-15h |
| Deep cycle wear-down |
None |
High |
Very high |
| Hazardous material |
None |
Yes |
Yes |
| Estimated cost |
$5,200 |
$11,200 |
$5,200 |
Source: ESTOR
About
the Author
Isidor Buchmann is the founder and CEO of Cadex Electronics
Inc., in Vancouver BC.
Mr. Buchmann has a background in radio communications
and has studied the behavior of rechargeable batteries in practical, everyday
applications for two decades. Award winning author of many articles and books
on batteries, Mr. Buchmann has delivered technical papers around the world.
Cadex Electronics is a manufacturer of advanced battery chargers, battery analyzers
and PC software. For product information please visit www.cadex.com.
©
Copyright 2003 - 2009 Isidor Buchmann
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