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Back in January, we told you about IBM’s quest to build a rechargeable lithium-air battery that could theoretically let an electric car travel 500 miles on a single charge.
Since then, more firms have joined IBM on its Holy Grail adventure, leading to a flurry of stories heralding the end to range anxiety and a future where charging your car only takes place once a week.
But do we really need a 500-mile electric car battery? Or do lithium-air batteries offer something much more useful?
200, 300 miles, not 500
As most Americans what they think of as the limit of how far they can drive without stopping, and they’ll say somewhere between 200 and 300 miles.
That’s because your average person needs to visit the bathroom after 4 hours, especially if they’ve consumed too many high-caffeine road-trip drinks.
At an average speed of 75 mph, on a perfectly clear freeway, that 4 hours equates to 300 miles.
Admittedly, rapid charging, currently capable of offering an 70 percent recharge to cars like the 73-mile EPA-rated 2012 Nissan Leaf in 30 minutes, takes longer than going to the bathroom.
After 4 hours however, it’s highly unlikely that you’ll immediately return to your car after visiting the bathroom. More likely, especially if you have kids, will be a 20-30 minute break for food or drink.
And that gives you at least 30 minutes to recharge.
Longer range...
Because lithium-air batteries rely on the chemical reaction between the lithium-ions and oxygen in the air, lithium-ion batteries have a higher energy density than traditional rechargeable batteries which rely on chemical reactions between two stored metals within the battery.
In a nutshell, this means that per pound of weight, lithium-air batteries can store more energy, which equals longer range.
Remember however: that longer range wouldn’t be needed for 95 percent of all daily driving,
Isn’t that just extra complexity and cost for nothing?
or better efficiency?
There’s a problem however. Weight. The heavier something is, the more energy is needed to push it along.
At the moment, lithium-ion battery packs used in modern electric cars account for their increased weight when compared with conventional gasoline cars.
Take the 2012 Nissan Leaf for example, where the battery pack and its control module weigh a massive 660 pounds. And it’s that weight that accounts for the Leaf’s 73-mile EPA-approved range per charge.
Reduce an electric car’s weight by using a more energy-dense battery, and it will travel much further using the same amount of stored energy as an electric car with a less energy-dense battery pack.
Smaller, lighter battery = lower cost
If rechargeable lithium-air battery packs become commercially viable, the reduced physical battery pack size could help reduce the overall cost of building and buying an electric car.
And with less weight, it should cost even less to operate an electric car with a lithium-air battery compared with a traditional lithium-ion battery of a similar energy capacity.
Reduced manufacturing costs and better efficiency on the road should then translate to lower sticker prices and faster adoption -- even if electric vehicle range remains somewhere between 150 and 200 miles.
You choose
Ultimately, lithium-air batteries may offer the holy grail of 500-mile per charge range. But ask yourself this: Do you really need it?
Or would you rather have a lighter, more agile electric car that costs less to run?
Let us know in the Comments below.
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Have an opinion?
About IBM: they have announced that their technology won't hit the market until somewhere between 2020 and 2030 which sounds like a diplomatic way of saying "sorry but we have nothing sofar".
There is also the sticky issue of ownership of batteries being swapped out. You're stuck with a lease/subscription model which increases the price of use in hopeful exchange for a lower up front cost.
I think speed of charging should be the goal, not so much range. After all, 100 mile range in the Leaf is much easier to live with if you can recharge in 10 minutes, as promised by Nissan's new DC chargers, rather than 7 hours on L2. A car that would have about a 200 mile range and recharge in 5-10 minutes would be the ideal sweet spot, balanced between range and cost and convenience.
I recommend the consumer choose what pack they want - 200, 300, 400 or 500 and pay accordingly.
I just want to be able to drive to San Diego and back, so 200-300 miles would be great. 100 miles comes up short.
I for one want to be able to take my new EV home to show off to my friends and family, to be an EV ambassador of sorts. Home is about 420 miles away, so either 200-300 miles with a quick charge option in between, or 500 miles without. I won't consider buying an EV with less than 200 miles as I consider that under achieving.
Come back to me once we've figured out how to get consensus on paying for a STATE OF GOOD REPAIR on the roads we've got. Since raising ANY tax for any reason is Communism. Or socialism. Or something.
In any case, we have total gridlock on transportation funding--Congress just extended the old program for a few months for the umpteenth time--and until we figure that one out, this is a pipe dream.
But I would be interested to know about the relative cost of
1) having inductive charging on one lane of each Interstate combined with a 16 KWH battery pack in each vehicle versus
2) having 80KWH battery packs in every vehicle in the USA.
2.) Li air batteries have some very significant challenges, since they carry high energy density & are potentially dangerous in a safety event and nobody in car industry went to LiCo batteries in cells phones (except Tesla who does not know better) since in a failure mode, you have raw Li metal in your battery which is highly reactive. The first thing IBM needs to address is how to handle raw Li in batteries in an automobile environment. Put a nail thru cell phone bat.
Nothing has ever stayed the same throughout history so why do we think the EV has to provide the same performance as an ICE vehicle? Will it even be necessary with our changing way of life?
What we really need is more QC stations and L2 stations. a 250 mile range vehicle that can be recharged in an hour or swapped in 5 minutes is more realistic. What Tesla currently offers is all one really needs but the charge time is still too slow
Its difficult to predict the direction recharging will take since the technology is in a state of flux. If it doesn't deliver comparable ICE range we just may have to accept the EV as limited/local use transport. With this scenario and widespread adoption a fast charge infrastructure would be viable that would allow longer travel with some caveats such as delays at stations.
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