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A Breakthrough Might Lead to EVs With Quintupled Ranges
Range anxiety is one of the big things holding back electric vehicle adoption in Canada. But a new battery breakthrough might deliver five times the range of today's batteries, eliminating range anxiety forever.
Over the past few years, the Canadian government has done everything in its power to encourage the adoption of electric vehicles (EVs). But part of the reason they've needed to do that is the fact that EVs still come with some downsides that make them less attractive than conventional vehicles.
One of the biggest of those downsides is range. The average EV range now sits at 313 km per full charge — well short of the average conventional vehicle, which can go approximately 482 km on a full tank. And unlike conventional vehicles, you can't always count on a charging station to save the day when your battery runs low.
The result is a natural barrier to electric vehicle adoption, particularly in the northern reaches of the country. There, running out of power could lead to a hazardous situation in a hurry. But recently, a breakthrough by a team of scientists at the University of Michigan may be on the verge of solving the range problem once and for all. Here's how.
Today's EV Battery Technology
Most all-electric vehicles on the road today rely on batteries made using lithium-ion technology. They're almost identical to the types of batteries found in smartphones, laptops, and other portable electronic devices. The reason for that is simple. It's that lithium-ion batteries check four important boxes that make them suitable for use in EVs. They feature:
- High power-to-weight ratio
- High energy efficiency
- Good performance at high temperatures
- A high number of charge cycles
The trouble is that lithium-ion batteries are relatively expensive to produce, and there are limits to how much power you can pack into them.
Today's Longest-Range EVs
Even with the limitations imposed by lithium-ion batteries, automakers have found ways to produce EVs that boast some impressive ranges. Using EPA mileage guidelines as a measure, the models on the market today with the best ranges include:
Tesla Model S Long-Range, at 652 km
Tesla Model X Long-Range, at 580 km
Tesla Model 3 Long-Range, at 568 km
Tesla Model Y Long-Range, at 525 km
Ford Mustang Mach-E California Route 1, at 491 km
As you may have noticed, four of the top five ranges come from a single manufacturer — Tesla — and all of them are the top-of-the-line of their respective models. They achieve those long ranges by including bigger, heavier batteries. And because an EV's battery makes up around 32% of its production costs, you won't find ranges like those on anything but upmarket vehicles.
A Replacement Technology Needed
Within battery technology circles, it's universally acknowledged that lithium-ion batteries are reaching the limits of their usefulness. What's needed is a lighter and more energy-dense replacement — and ideally, one that's cheaper to produce. That's the only way they believe it'll be possible to extend electric vehicle ranges to the point that they'll regularly exceed those of conventional vehicles.
And one of the prime candidates to serve as that replacement is lithium-sulfur batteries. Already, such batteries can exceed the capabilities of lithium-ion equivalents and could be produced on the same assembly lines with little retooling. But they have an Achilles heel: they can't be recharged as many times as the batteries they'd replace, making them a non-starter.
The reason for that is found in their internal chemistry. They're particularly susceptible to the formation of dendrites, which are solid metal microstructures that slowly destroy a rechargeable battery's capacity and eventually lead to failure. In lithium-ion batteries, those dendrites form too, and are one of the prime reasons for early catastrophic failure. The difference is that it's easier to inhibit them in lithium-ion power cells.
An Important Breakthrough
But a recent breakthrough by scientists at the University of Michigan could point the way to a solution to the lithium-sulfur dendrite problem. The team had been working with Kevlar aramid nanofibers — made from the same material as bulletproof vests — to find ways to inhibit dendrite formation in their lithium-sulfur batteries.
But they found that unlike in lithium-ion batteries, dendrite formation wasn't their only problem. It turned out that lithium-sulfur batteries also suffer from another issue. Inside the batteries, lithium and sulfur molecules combine into lithium polysulfides, coating the electrodes and leading to failure. To solve the problem, the team needed a way to allow lithium molecules to pass through the nanofibers, but block the all-but-identical lithium polysulfides.
The solution was to create negatively-charged pores in the nanofiber membranes. Doing so trapped the negatively-charged lithium polysulfide molecules while allowing the positively-charged lithium to pass through unimpeded. And the result, according to the team's leader, was a battery design that's "nearly perfect,".
The new battery technology still needs testing to make sure it's safe for use in electric vehicles. But so far, the results seem promising. According to the researchers, their battery design should be capable of around 1,000 charge cycles in the real world, which translates to about a 10-year lifespan in a vehicle. But that's just the tip of the iceberg.
Lithium-sulfur batteries offer far superior power-to-weight ratios over today's lithium-ion batteries. They could deliver roughly 5 times the range of a similarly-sized battery in today's vehicles. That would push the average range of an electric vehicle to an astounding 1,565 km with no other changes to their design.
And, they don't use cobalt, which is a rare — and therefore expensive — part of today's batteries. That means they'll be cheaper to produce, dropping the total cost of electric vehicles below that of conventional ones for good. In other words, we may have just witnessed the birth of the electric vehicle battery that will eliminate range anxiety — and the internal combustion engine — forever. And that's good news for both your wallet and the planet we call home.