2016 BMW 3-Series eDrive plug-in hybrid prototypeEnlarge Photo
When is a hybrid not a hybrid?
Potentially when it’s a conventional gas-powered car using an electrified powertrain.
Many automakers have announced that they will build some percentage of their car fleet as pure electrics. The gas-powered vehicles that remain will still need a significant boost in fuel economy.
The key to increasing fuel economy in these more conventional cars will be electrified, though not fully-electric, powertrains. They won’t all be full hybrids, and they certainly won’t all be plug-ins, as automakers try to keep costs down and offer these more efficient powertrains in more affordable cars.
Many of these systems rely on higher-voltage electrical systems than standard lead-acid batteries can provide. Yet automakers are looking for solutions that are cheaper than lithium batteries.
Enter the silicon-wafer lead-acid battery.
Buick Lacrosse Hybrid eAssist SystemEnlarge Photo
A new company called Gridtential has developed a technology that will allow automakers to use cheaper batteries to power advancements in electrified powertrains without jumping all the way to full hybrids with lithium or even nickel-metal hydride batteries.
Gridtential’s silicon-wafer lead-acid batteries use bi-polar technology—sending current the short way through battery plates rather than the long way, according to Gridtential Chairman Ray Kubis—that can increase power output and charge rates compared with lead-acid or lithium batteries. The resulting batteries cost one-third as much as lithium, yet are one-third smaller and lighter than standard lead-acid batteries.
In cars, they can increase the capabilities of stop-start systems by enabling more frequent stop-start cycles than lead-acid, power major systems such as the electric supercharger on Audi’s new SQ7 TDI, and allow automakers to build more capable micro-hybrids that operate a lot like a Toyota Prius but with perhaps a half-mile of electric range and more electric power and braking regeneration, which can allow gas engines to be smaller.
Kubis told Green Car Reports in an interview that he expects the batteries would allow automakers to boost fuel economy by 5 to 15 percent, depending on how it was applied.
The batteries can be configured to produce 24, 36, or 48 volts, Kubis says. Part of the challenge was to develop silicon that could withstand the acidic electrolyte environment in lead acid batteries.
Standard lead-acid battery factories can produce the silicon-wafer batteries and reduce the demand for automakers and suppliers to invest in greater lithium battery production.
CHECK OUT: Lead-Carbon Batteries The Next Step For 'Micro Hybrid' Vehicles? (2013)
The technology will take root in Europe and China first, around 2020, and make its way to the U.S. later, he says. Automakers such as Audi, BMW, Mercedes-Benz, and VW are developing cars that use it.
Kubis says the batteries will become the primary batteries in cars where they’re used, with step-down converters to power 12-volt accessories such as lights, wipers, and stereos. They may live under the hoods of cars, but unlike today’s lead-acid starter batteries, users won’t be able to swap them out with a new one from Wal-Mart.