The rise and rise of the lead acid battery – an old faithful becomes the new

high tech

Lithium and cadmium are perhaps the metals that spring to mind when we think of the high tech

rechargeable battery revolution. But let’s not write-off the lead acid battery just yet. The world’s

oldest rechargeable energy storage solution may be about to reveal a few surprises.

Lead acid batteries aren’t well suited to small portable applications requiring low energy-to-weight

ratios, like cell phones, laptops, cameras and Kindles that need a light, uninterrupted power supply

away from the wall socket. But for the high power output, stability, safety and life-cycle cost

required for applications like electric vehicles or grid energy storage solutions, a new class of lead

acid batteries may be difficult to beat.

Lead acid batteries’ major drawbacks have always been that they perform poorly in hot climates and

rapidly deteriorate when power is repeatedly drawn from them in a partial state of charge.

But amazingly, after over 100 years of lead acid battery use, these limitations were recently

overcome with the discovery of a new class of lead acid battery that can be continuously charged

and discharged with very little deterioration.

Traditional lead acid batteries work by placing two electrodes – one lead the other lead-dioxide –

into a bath of dilute sulfuric acid. If the electrodes become connected by a conductor the resulting

chemical reaction gradually drags the sulfur out of the acid and deposits it onto both electrodes.

Lead-sulfate is created at the electrodes, the bath becomes closer to pure water, and huge numbers

of electrons migrate along the conductor. We exploit these migrating electrons as our electrical

power.

In 1859 French scientist Gaston Planté's stroke of genius was to recognize that this battery could also

work as an energy storage solution – that is, if we produced electricity elsewhere, and those

electrons were forced through the battery in the opposite direction, the chemical reaction would

reverse: the bath would revert to sulfuric acid and the two electrodes would once again become

lead and lead-dioxide respectively.

However under consistent charge and discharge, the deposition and recovery of sulfur on the

negative electrode tends to become less and less efficient as the lead sulfate crystallizes and inhibits

operation.

The new breakthrough technology still looks like every other 12 volt battery, but is in fact a hybrid

battery/capacitor which is highly efficient, long lasting, readily recyclable and does not suffer from

significant lead sulfate crystallization. Hence it can provide an uninterrupted power supply in any

state of charge – exactly the technology required for large scale grid storage and electric vehicle

production.

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Ecoult delivers complete energy storage solutions and modules powered by the breakthrough

UltraBattery technology – a hybrid lead-acid energy storage device containing both an Ultracapacitor

and a battery in a common electrolyte. Ecoult’s storage solutions manage intermittencies, smooth

power and shift energy in a safe, reliable and environmentally sound way – the energy storage of

choice for grid ancillary services, wind and solar farms, remote Microgrid Energy Storage, dual

purpose and diesel microgrid efficiency applications.

For more details regarding our energy storage solutions visit our website or

call us at our toll free number +61 (02) 9241 3001.