The Next Thing in Electric Fleet Vehicles?

 

There’s obviously a lot of talk about the coming wave of EV and autonomous vehicles in both consumer and commercial markets. Despite the fanfare (or infamy) of these coming technological evolutions, there are a couple of present-day roadblocks that fleet managers are looking to solve. One of the biggest issues with EV is the battery life relative to the distance a vehicle can travel. For long haul trucking, we’re just not there yet. 

But the future holds a lot of promise for both EV and fuel-powered trucks. So we sat down with Gleb Yushin, Professor, School of Materials Science and Engineering at Georgia Tech to talk about his research and what’s in store for next-generation battery options in trucking. 

 

Better Batteries? Let’s Talk About Electrolytes

There are two principle types of electrolytes used in batteries: liquid electrolytes and solid state electrolytes. Truck and car batteries contain a liquid often referred to as “battery acid.” These are, in fact, liquid electrolytes. In most cases, these batteries are safe. But in the case of an accident, the standard liquid electrolyte battery can become a liability should there be a fire as the liquid inside the battery is flammable. These batteries may also emit flammable hydrogen gas. 

So when it comes to safety, it stands to reason that a non-volatile alternative to liquid electrolyte batteries would be desirable. Dr. Yushin’s team at Georgia Tech has done just that: they’ve created a battery that uses solid state electrolytes that is safer. Dr. Yushin explains this in a bit more detail:

“Solid electrolytes do offer additional safety and (in the case of our technology, potential cost savings). This could be particularly important for use in electric planes or electric or hybrid electric ships or submarines, where safe evacuation within 5-10 min (or even 20-30 min) is often not feasible.

For semi-trucks, safety may also be more important than for passenger vehicles. This is because a larger-sized semi truck can do so much more damage to the road or bridge or building if it catches on fire or explodes, for example, due to spilled diesel fuel or collision (just recently I read about 17 semi-trailers caught fire due to fuel spill).

While electric semi trucks are likely going to be safer than diesel trucks, the all-solid state battery-powered semi trucks would offer the ultimate safety.”

How Does This New Battery Technology Impact Price?

There’s great news for curious battery manufacturers and fleet owners alike: Yushin’s technology isn’t just safer and more stable. Existing factories can produce them without intensive retrofitting that would be cost-prohibitive:

“Because some of the solid electrolytes that we demonstrated can potentially make battery preconditioning (at the factory) faster and safer and, we expect, meaningfully reduce the battery factory testing and transportation expenses, one may estimate up to 15% direct cost savings.

However, because the reported solid state battery manufacturing technology is compatible with novel anode and cathode chemistries…the eventual cost-savings for the next-generation battery technologies could be significantly larger (up to 3x, longer-term).”

The other significant improvement with Yushin’s technology is around the cell density of his batteries. “At the vehicle level, higher volumetric energy allows for a longer driving range for the same battery pack size,” says Yushin. 

But the big payoff is in the weight of these batteries:

“Higher gravimetric energy enables lighter batteries. This is particularly important because of the federal limits on the total/loaded truck weight on the highway (80,000 Lb total vehicle weight).

So if a regular empty truck weighs 35,000 Lb, it can carry up to a 45,000 Lb load. With, say, a 1000 kWh battery pack and say, 200 Wh/kg battery pack-level specific energy the battery weight would be 5,000 kg or 11,000 Lb. 

Even if the electric truck without a battery weighs, say, 30,000 Lb, the 11,000 Lb battery would reduce the max load by 13%. However, if the battery weight is reduced by, say, 2-2.5x there would be no reduction in the maximum load when moving from diesel semi truck to an electric semi truck.

Since electricity could be 10x cheaper than diesel/gasoline such lighter batteries would enable significant cost savings in addition to protecting the planet” says Yushin.