New Lead Acid Systems
Lead acid batteries continue to hold a leading position, especially in wheeled mobility and stationary applications. This strong market appeal entices manufacturers to explore ways to make the batteries better. Improvements have been made and some claims are so promising that one questions the trustworthiness. It is no secret that researchers prefer publishing the positive attributes while keeping the negatives under wraps. The following information on lead acid developments was obtained from available printed resources at the time of writing.
Firefly Energy
The composite plate material of the Firefly Energy battery is based on a lead acid variant that is lighter, longer living and has higher active material utilization than current lead acid systems. The battery includes foam electrodes for the negative plates, which gives it a performance that is comparable to NiMH but at lower manufacturing costs. Design concerns include microtubule blockage through crystal growth during low charge conditions. In addition, crystal expansion causes a reduction of the surface area, which will result in lower capacity with aging. Pricing is also a concern. It currently costs about $450 to manufacture a Firefly battery as opposed to $150 for a regular lead acid version. Firefly Energy is a spin-off of Caterpillar and went into bankruptcy in 2010.
Altraverda Bipolar
Similar to the Firefly Energy battery, the Altraverda battery is based on lead. It uses a proprietary titanium sub-oxide ceramic structure, called Ebonex®, for the grid and an AGM separator. The un-pasted plate contains Ebonex® particles in a polymer matrix that holds a thin lead alloy foil on the external surfaces. With 50–60Wh/kg, the specific energy is about one-third larger than regular lead acid and is comparable with NiCd. Based in the UK, Altraverda works with East Penn in the USA, and the battery is well suited for higher voltage applications.
Axion Power
The Axion Power e3 Supercell is a hybrid battery/ultracapacitor in which the positive electrode consists of standard lead dioxide and the negative electrode is activated carbon, while maintaining an assembly process that is similar to lead acid. The Axion Power battery offers faster recharge times and longer cycle life on repeated deep discharges than what is possible with regular lead acid systems. This opens the door for the start-stop application in micro-hybrid cars. The lead-carbon combination of the Axion Power battery lowers the lead content on the negative plate, which results in a weight reduction of 30 percent compared to a regular lead acid. This, however, also lowers the specific energy to 15–25Wh/kg instead of 30–50Wh/kg, which a regular lead acid battery normally provides.
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, prolonging the lifetime by a factor of four over customary lead acid systems and producing 50 percent more power. The manufacturer also claims that the battery is 70 percent cheaper to produce than current hybrid electric vehicle (HEV) batteries. CSIRO batteries are undergoing road trials in a Honda Insight HEV and show good results. Furukawa Battery in Japan licensed the technology. The CSIRO battery is also being tested for start-stop applications in micro-hybrid cars to replace the lead acid starter battery. This battery promises extended life when exposed to frequent start-stop conditions and is able to take a fast charge.
EEStor
This is the mystery battery/ultracapacitor combination that receives much media attention. The battery is based on a modified barium titanate ceramic powder and claims a specific energy of up to 280Wh/kg, higher than lithium-ion. The company is very secretive about their invention and releases only limited information. Some of their astonishing claims are: One-tenth of the weight of a NiMH battery in a hybrid application, no deep-cycle wear-down, three- to six-minute charge time, no hazardous material, similar manufacturing costs to lead acid, and a self-discharge that is only 0.02 percent per month, a fraction of that of lead acid and Li-ion.
Comments
The original flooded lead-acid battery using lead-antimony grid alloy and pasted plates is by far the best technical, most economic battery ever invented. The change to lead-calcium negative grid alloy was a CLEVER move - the change to lead-calcium alloy positive grid alloy was a STUPID move. The special oxygen recombination, fibreglass mat / gel, VRLA, maintenance free batteries are just plain junk. Should have stuck to the old flooded technology, added some space for extra electrolyte, put on inversion protection, a pressure control valve to keep the cell interior above ambient pressure. Will last twice as long as the so-called maintenance free junk that was designed by sales people and definitely not in the laboratory.
I will explain how gassing and positive plate wear can be VASTLY reduced in ordinary flooded batteries next month.
Hello John,
I find your comments candid and interesting especially in the light of all the marketing hype propogated by various leading brands.
Please may I request some technical data to back up your claims. I am in search for excellence for consumers as well as for the environment that sustains us.
Kind Regards,
Afzaal Khan
Hello Afzaal
Part of the answer to your question can be found on the following website:
www.batteryvitamin.net/sulfation_pulse_treatment_surprise.
The rest of this rather large website contains more information about lead-acid batteries than you can absorb in one “sitting”.
Good luck.
Best regards
John Fetter
time to charge a12v. 55ah battery with 125 milliamps
12v 55Ah @ 125mA = 3 weeks
Gassing and positive plate corrosion can be reduced by introducing a substance into the electrolyte of the battery that is made of molecules that have a specific shape and that carry an electric charge. The electric charge encourages the molecules to migrate as ions to the NEGATIVE plates and to adhere on their surfaces. When the molecules attach, they become arranged like trees in a huge forest. There is little space between the “trees”, just enough to allow the comparatively small ions that govern battery functioning to pass through. When metal dissolves in the battery electrolyte, it forms bulky hydrated cations. These are too big to get through the spaces between the “trees”, so they remain in solution.
The metal originates from the grids of the positive plates. It gets into the solution as result of a process known as corrosion. Corrosion is an inevitable result of repeated recharging of the battery. If the solution containing the metal becomes saturated, metal cannot get into solution and, incredibly, the process of corrosion is brought almost to a complete stop.
The substance can be modified to become voltage sensitive. The shape of the molecules can be made to react to the voltage present on the negative plate. Careful design of the molecule can cause the spacing between the “trees” to change, so that during normal operation, the spacing is large and during overcharge, the spacing is small. This allows the battery to function completely normally throughout its operating range, except when it becomes overcharged.
When a battery is overcharged, it gasses and consumes water. However, the molecules of the substance now grow wider just as the battery becomes overcharged, pinching off the channels that are carrying water molecules on their way to become electrolyzed to hydrogen at the surface of the negative plates.
This process is subject to Faraday’s First and Second Laws of Electrolysis. Simply limit the top-of-charge voltage to around 2.55V per cell and the water consumption falls dramatically.
The battery lasts about twice as long and uses about half the amount of water.
Bear in mind it would be a bad career move for the technical people working in the battery industry to get involved in making batteries last longer. The person in charge is likely to translate an extension in battery life into a reduction in battery sales.
YOU KNOW EVERYTHING ABOUT BATTERYS
i want to know about lead acid batteries