August 10, 2022

This EV uses a tiny amount of lithium in its battery

Now that the EV revolution is underway, and car manufacturers are starting to electrify their lineups in earnest, suddenly there is a lot of hand wringing over the lithium supply. Lithium is a key ingredient to the batteries that most EVs run on, and like everything on this planet, there's a finite amount of it.

The average electric car needs about 8 kg of lithium in its battery. So as EV production accelerates, soon the industry will reach the point where the rate of EV production is limited by the availability of lithium.

Meanwhile, global heating is proceeding. Already in this northern-hemisphere summer of 2022 we're dealing with extreme high temperatures, deepening drought or flash drought, extreme rainfall, just weirdness all around,. All that while we're only at 1.2C warming, well below the 2C limit set in the Paris climate accord. We need to stop carbon emissions, and we need to do it fast.

So a bottleneck in electrifying our transportation is something we don't need right now. But it doesn't have to be that way.

It's time to look outside the box. A steel box with four wheels is what we tend to think of when we hear "EV". But what we need to decarbonise is not cars; but the transportation of people. If you think about it that way, that opens up a whole new world of solutions. Think of the train, which has a lot more than four wheels, all steel.

Then there's the EV with two wheels, better known as the e-bike. I know, bikes are not for everyone. Hey, neither are cars. But we are considering here how to move people, and both bikes and cars move people. (And let's face it, most cars get used by a single person, the driver, most of the time).

So let's try this: let's do an EV comparison with a twist: let's compare the Nissan Leaf and the Pedego City Commuter. Both are utilitarian vehicles, both run on a battery, and both can be used to get yourself to work or to your errands. For both, we look at the version with the higher range.

The Nissan Leaf with a range of 212 miles has an electric motor of 214 HP powered by a 60kWh lithium-ion battery. Its effective efficiency is 121 MPGe, the electric equivalent of the miles per gallon number we're familiar with.

Now let's take a look at the Pedego City Commuter. Its range is only 60 miles. This is not as impractical as it sounds, as its speed is capped at 20mph; most people would not use a bicycle for a commute that's more than 20 miles, anyway. 

Because it has a lot less mass to propel, its pedal-assist is powered by a 749W motor. In horsepower-speak that would be - drumroll - 1 HP. One horsepower. I mean, that's  just adorable.

That single horsepower comes out of a battery with a capacity of 720Wh: also itty-bitty compared to car batteries that are measured in kiloWatt-hour (kWh) units. But for the purpose of cutting carbon fast, small is not only adorable: it is positively awesome. Why? To begin with, this EV has an efficiency of 2853 MPGe. But more importantly for speeding the transition, it takes a minuscule amount of precious lithium to build this battery.

Suppose that it takes the average 8kg of lithium to make the Nissan's battery with its 60kWh capacity. Assuming that there is a linear relation between the amount of lithium in a battery and its capacity, this means that the bicycle battery (0.72 kWh) needs - another drumroll - 96 grams of lithium. (If you don't speak metric: that's 17 pounds of lithium for the car battery versus 3.4 oz for the bike battery).

For the lithium it takes to build a single car battery you can build more than 80 bicycle batteries.

I'm of course not saying that this will move the electrification of transportation ahead 80 times faster. As we've agreed, the bike is not for everyone. But if you do bike, an electric bike is more fun, it's faster, it gets you where you're going without a sweat. E-bikes are much cheaper to buy and operate, don't require the additional expense of insurance, and don't require a driver's license. Should the battery ever run out during your trip, you're not stranded, you can still pedal home. These are all reasons for riding your e-bike farther and more often, and leaving your car at home.

In the early days of mobile communications, people had cell phones in addition to their landlines. But over time lots of people gave up their landlines altogether. It could be like that for e-bikes and e-cars. People might dedicate their garage to the family e-bikes, and rent a car when the occasion requires - electric, of course.

You may also like:

No comments:

Post a Comment

You have an opinion: Let's hear it.
(Comments are moderated; please be patient).