MIT Engineers Produce the World's Longest Flexible Fiber Battery (mit.edu) 35
Researchers have developed a rechargeable lithium-ion battery in the form of an ultra-long fiber that could be woven into fabrics. From a report: In a proof of concept, the team behind the new battery technology has produced the world's longest flexible fiber battery, 140 meters long, to demonstrate that the material can be manufactured to arbitrarily long lengths. The work is described today in the journal Materials Today. [...] The new fiber battery is manufactured using novel battery gels and a standard fiber-drawing system that starts with a larger cylinder containing all the components and then heats it to just below its melting point. The material is drawn through a narrow opening to compress all the parts to a fraction of their original diameter, while maintaining all the original arrangement of parts.
While others have attempted to make batteries in fiber form, [says MIT postdoc Tural Khudiyey, a lead author on the paper], those were structured with key materials on the outside of the fiber, whereas this system embeds the lithium and other materials inside the fiber, with a protective outside coating, thus directly making this version stable and waterproof. This is the first demonstration of a sub-kilometer long fiber battery which is both sufficiently long and highly durable to have practical applications, he says. The fact that they were able to make a 140-meter fiber battery shows that "there's no obvious upper limit to the length. We could definitely do a kilometer-scale length," he says.
The 140-meter fiber produced so far has an energy storage capacity of 123 milliamp-hours, which can charge smartwatches or phones, he says. The fiber device is only a few hundred microns in thickness, thinner than any previous attempts to produce batteries in fiber form. In addition to individual one-dimensional fibers, which can be woven to produce two-dimensional fabrics, the material can also be used in 3D printing or custom-shape systems to create solid objects, such as casings that could provide both the structure of a device and its power source. To demonstrate this capability, a toy submarine was wrapped with the battery fiber to provide it with power. Incorporating the power source into the structure of such devices could lower the overall weight and so improve the efficiency and range they can achieve.
While others have attempted to make batteries in fiber form, [says MIT postdoc Tural Khudiyey, a lead author on the paper], those were structured with key materials on the outside of the fiber, whereas this system embeds the lithium and other materials inside the fiber, with a protective outside coating, thus directly making this version stable and waterproof. This is the first demonstration of a sub-kilometer long fiber battery which is both sufficiently long and highly durable to have practical applications, he says. The fact that they were able to make a 140-meter fiber battery shows that "there's no obvious upper limit to the length. We could definitely do a kilometer-scale length," he says.
The 140-meter fiber produced so far has an energy storage capacity of 123 milliamp-hours, which can charge smartwatches or phones, he says. The fiber device is only a few hundred microns in thickness, thinner than any previous attempts to produce batteries in fiber form. In addition to individual one-dimensional fibers, which can be woven to produce two-dimensional fabrics, the material can also be used in 3D printing or custom-shape systems to create solid objects, such as casings that could provide both the structure of a device and its power source. To demonstrate this capability, a toy submarine was wrapped with the battery fiber to provide it with power. Incorporating the power source into the structure of such devices could lower the overall weight and so improve the efficiency and range they can achieve.
Interesting prospects (Score:3)
Interesting challenges to find a way to use this fiber battery in clothing and other items. Imagine a single board computer where the PCB is embedded with enough of this fiber battery to power it for a day. Of safety vests that use EL wire to glow at night. We'll have to see how people think to use it and when it comes out of the lab and into the experimenter's hands.
What happens when you cut it? (Score:3)
ISTM that the longer the fibre, the greater the chance of it being accidentally cut or broken - or even simply have the protective outer layer worn away. Should we expect this one to ignite or does its small size reduce the danger of it starting a fire. Especially it it was woven into a flammable fabric.
Re: (Score:3)
RTFA. :-)
There is a short video (GIF?) showing a lit LED while someone snips the fiber. No issues.
That's weird (Score:2)
Re: That's weird (Score:2)
Just don't make it out of animal skins, they might come back to life. Zombie coat!
Re: (Score:3)
You can also throw away your electric coat when the battery needs replacing. By Grabthar's hammer, what a savings!
Let me rephrase that (Score:2)
The fact that they were able to make a 140-meter fiber battery shows that "there's no obvious upper limit to the length. We could definitely do a kilometer-scale length," he says.
The fact that I am able to walk all the way to the store shows that "there's no obvious upper limit of walking distance. I could definitely walk all the way to the Moon", I say.
Re: (Score:3)
You can't walk to the moon for reasons which have nothing to do with distance (lack of a walkable surface, lack of atmosphere). But It's not impossible to walk as far as the moon. At 20 miles a day, it would take you about 33 years. Somewhat impractical of course, and the same may be true of kilometre-long batteries - possible, but far easier to make multiple short ones.
Re: (Score:2)
Don't take it literally. I wanted to point out that reaching X doesn't mean you can reach 10X or 100X.
Re: (Score:2)
No, I wasn't taking it literally. Just pointing out that the limit is often practicality not possibility. You can walk coast to coast across the USA - but it's more practical to take a plane. You probably could build a 500-storey skyscraper - but it's more practical to build 50 10-storey ones. Similarly it might be possible to make a battery kilometres long, but it might be impractically expensive, too difficult to handle etc. The cut-off point for making things is usually "not worth the effort/cost" rather
Applications (Score:2)
Trying to think of some applications for this. Charging a phone is out of the question, 123mAh is nothing. Typical phone battery is in the 3000-4000mAh range, plus charging losses, it might get you 1-2%.
Clothing with integrated electronics could be interesting. Lighting for fashion, things like fans for keeping you cool or heating coils for keeping you warm. Both of the latter two functional ones have been available for a while already, and the current solutions seem more convenient. You have a battery pack
Re: Applications (Score:3)
I think the advantage would be harvesting energy in motion over a fabric. So you could envision a flag that lights up and is powered by the motion of the wind.
Re: (Score:2)
I don't think you would want a battery for that though, you would want something that can convert mechanical energy into electrical energy.
As an engineer I'd either go solar (on top of the flag pole) or mains powered. Tried and tested, cheap, reliable. Change the flag any time you like with another cheap one.
Re: (Score:2)
But that wouldn't work at night, when the illumination would be more visibe.
Your point about cost, though sounds correct. But we've got no idea what this would cost when mass-produced. Still, the flag would need to not only harvest the energy of motion, it would also need to have embedded LEDs, as well as the battery to hold the illumination for when the wind's quiet. Doesn't sound that cheap, but you could hang it anywhere, and move it about as you choose. Definitely only a specialty product, which mea
Re: (Score:2)
The solar wouldn't work at night? Sorry, I should have said solar+battery, I thought it was implied. Like solar garden lights, or motion sensor lights.
Re: (Score:2)
OK, but the system you're describing isn't a luminous flag, which I believe the original poster was suggesting. Such systems already exist, so they do work, how well I'm not sure, but the effect would be different.
OTOH, I'm not really convinced that the system he was suggesting would work. Certainly if you harvest much of the energy of motion, you're going to make the flag a lot stiffer. It might drape about the same way, but it wouldn't wave in the wind as expected, though I don't know just *how* stiff
Re: (Score:2)
No worries.
There are people on /. that somehow learned internet and typing literally "over night".
In their childhood they bravely obeyed pop and mom and went to sleep before the sun set. And woke up - ah my dream to be able to do that again - fairly after sunset.
Now as they aged, they realized: at night there is no sun. And feel urged to tell it everyone to warn us about this unfortunate happenstance of our environment.
But no fear, brave "HiThere", when you sleep sound at night, I kill the vampires lurking
Re: (Score:2)
There's literally no point to using this battery technology unless you need to put a battery in something that's 100% flexible, and moreover, made of cloth.
Most applications would be better served with a small traditional cell (pouch or coin) hidden in a lapel or similar.
With the low energy density it's hard to make a case for these frankly. If you could get enough of the stuff into a garment to make it self-heating (or cooling!) without any hard cells then it might be useful, but it doesn't appear that's a
Sub-kilometer? (Score:2)
Re: (Score:3)
What is this supposed to mean - " This is the first demonstration of a sub-kilometer long fiber battery which is both sufficiently long and highly durable to have practical applications"? Are there a bunch of kilometer-long batteries out there already, making that comparison meaningful? Is there something new about a battery being both durable and less than a kilometer long?
The answers to your questions are in the sentence in TFS immediately preceding the one you quoted: While others have attempted to make batteries in fiber form, [says MIT postdoc Tural Khudiyey, a lead author on the paper], those were structured with key materials on the outside of the fiber, whereas this system embeds the lithium and other materials inside the fiber, with a protective outside coating, thus directly making this version stable and waterproof. I believe that the phrases, "in fiber form" and "s
WOULD BUY TOY SUB ... (Score:2)
... for bathtub use.
Who's with me? Surely there must be at least a couple of other /.ers who bathe from time to time. (My roommate definitely isn't one of them; sigh.)
After a few cycles... (Score:2)
Low density but good safety (Score:2)
This 140m long fiber has less capacity than the LiPo in my PineTime smartwatch, which is about the size of two quarters stacked on top of each other. The volume of this fiber battery looks like it could be easily an order of magnitude larger. I would also guess that the charge/discharge rate is pretty terrible for a single long fiber but this could be improved with a battery of short fiber cells.
However being fire-resistant, waterproof, and able to operate after being cut could make it useful for safety-cri
Clothing that explodes into a fireball! (Score:2)
Re: (Score:2)
Comment removed (Score:3)
Explosively Flammable Fabrics? (Score:2)
I also want to know what its effective resistance per meter is. At some point physics says trying to get power out of a l