Published on January 17th, 2017 | by Roy L Hales0
Where Silicon Joule Lead Batteries Outperform Lithium
January 17th, 2017 by Roy L Hales
Originally published on The ECOreport.
Gridtential raised another $6M in investments. These funds will be used to target what CEO Chris Beekhuis described as the inevitable shift from 12V to 48V high-voltage systems in hybrid electric vehicles. Gridtential’s Silicon Joule battery uses an advanced lead-acid design with a silicon substrate for higher energy density, longer cycle life, and deeper depth-of-discharge. He described two areas where Silicon Joule lead batteries outperform lithium.
Areas Where Silicon Joule Lead Batteries Outperform Lithium
Gridtential is not proposing that lead batteries be used for full electric vehicles.
“It’s all about energy density per weight. Although the Silicon Joule battery is at least twice the energy density of a traditional mono-polar battery, when you start getting into higher energy ranges it is still too heavy for full electric drive. We think lithium is the right solution for applications of more than a 40 mile range. Something with a very high energy density, like lithium or possibly hydrogen, makes a lot of sense,” said Beekhuis.
#1: Hybrid & Short Range Electric Vehicles
He believes it may be another decade before fully electric vehicles are sufficiently cost-competitive to take over. Gridtential’s target market is the hybrid vehicles which currently dominate the electric market.
A shift from 12 to 48 volt batteries is occurring because of the need for a higher power system to accelerate from a stop, regenerate the energy from braking and to power the many “creature comforts” and navigational aids being offered to customers.
“In today’s combustion engines, many of the devices, like air conditioning or power steering, are belt-driven devices. You are driving a belt all the time in preparation for when that device is needed. Electric motors replace that device with something that is powered on demand,” said Beekhius.
Supplying the electric systems to meet those demands means that smaller combustion engines can be used to power the same sized vehicles.
Lead batteries are the obvious choice to power these systems.
“Lead has a very high power density, it has a better chemistry for high power than lithium. The bi-polar architecture, which is the basis for (Gridential’s) Silicon Joule technology, takes advantage of that very high power density and allows us to deliver much higher power than a traditional mono-polar battery.”
Beekhuis also pointed out that whereas only 5% of lithium is reused, lead is 100% recyclable.
Lead car batteries are one of the most recycled consumer products on the planet. In the western world, more than 99% of them are currently being recycled.
#2: Grid Applications
There are now days when nations like Germany and Denmark generate more energy from wind and solar than they can use domestically.
“There is a clear need for them to use energy storage and, If you are pairing batteries with renewable energy, it would be nice for the batteries to also be sustainable,” said Beekhuis.
Battery banks also play an invaluable role in shoring up North America’s aging grid. Beekhuis gave the example of an average distribution line, which takes 12 – 15 years to build. There are many regions in the United States that no longer possess the capacity to meet demand. A battery bank, built in 9-12 months, can fill the gap.
“That’s an excellent short-term solution while we reconsider, do we want to extend the grid in the way it was built 100 years ago or do we go to a more distributed model with local generation and storage?”
Lead batteries have a number of advantages over lithium in grid and microgrid applications. They can withstand colder temperatures and do not require the same expensive cell-by-cell management.
Lead is the dominant energy storage medium for grid and telecom today.
“Where it has issues is in what we call cycle life: the number of times you can cycle it, especially when you cycle very deeply and when you cycle quickly,” said Beekhuis.
Silicon Joule’s bi-polar technology has a significant advantage in that it distributes current uniformly across the active material. This allows them to discharge very deeply without reducing the cycle life and, consequently, battery banks using Silicon Joule technology only need a third to a half of the capacity required by a traditional lead battery bank.
“The overall cost of the battery bank is lower and that same battery bank will last longer,” said Beekhuis.
He added, “We call our company Gridtential because we saw a very strong opportunity to take the incumbent technology, leverage its infrastructure and produce something that is much more efficient, cost effective in its application, and supports the 2-4 hour time shifting of energy needed to fully utilize the benefits of renewables. It was only recently that we realized the power density and capacity of our battery would also allow it to fit in to what has become the focus of the automotive industry.”
Photo Credits: IAA 2013: Porsche Panamera S e-hybrid (Plug-in IAA Frankfurt 2013) – Photo: Raphael Jahn /MotorBlog.com via Wikipedia; Chris Beekhuis, CEO of Gridential; Silicon Joule Battery powering an electric scooter; A Silcon Joule battery