Mobile device battery of the future could charge while the user walks around the block

posted by Alan F. / Jan 06, 2016, 11:49 PM

Mobile device battery of the future could charge while the user walks around the block

Remember those self-winding watches that would use the movement of your wrist to wind the mechanism inside so that the timepiece would be powered up perpetually? Researchers at MIT have developed a battery that can "harvest energy" from a person's natural movements including walking.

The technology involved is similar to the lithium ion batteries used by many smartphones, but would be flexible enough to use in wearable devices. While a li-ion battery used in a handset takes in power and stores it until needed, MIT's new cell takes in mechanical energy and converts it to electricity.

One part of the battery would be attached to an arm or a leg. The everyday movements would force the bending of two thin sheets of lithium alloys, separated by a layer of porous polymer soaked with liquid electrolyte. The bending squeezes lithium ions through the soaked polymer creating an electrical current between the two lithium alloy sheets. That current could be used to power a smartphone, tablet or smartwatch.

While other methods that harvest mechanical energy had small current output and short pulse duration, the MIT technology had large current output and long pulse duration. All of this means that future smartphone and wearable devices powered by such a battery could be fully charged after a short, brisk walk around the block.

"This work is very interesting and significant in the sense that it provides a novel approach to converting mechanical energy through an electrochemical route, using a simple design and device structure. More significantly, the output current from the demonstrated device is very large, with a long pulse duration. This is very important for practical applications, since most other mechanical energy harvesting methods suffer from the issues of small current output with short pulse duration."-Wu Wenzhuo, assistant professor of industrial engineering, Purdue University

Don't expect this technology to be powering mobile devices anytime soon. While testing shows that the system is stable, there is still much more work to be done before this technology becomes ready for prime time.

The process was described in a paper written by MIT professor Ju Li, graduate students Sangtae Kim and Soon Ju Choi, and four others.

This illustration shows the two lithium electrodes sandwiching a layer of electrolytes. When the sandwich is bent, the lithum ions are pushed into the middle layer of electrolytes creating an electrical current

source: MIT via BGR

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25 Comments

1. phonehome

Posts: 812; Member since: Dec 19, 2014

Still not exactly sure how this would work. Would it involve a wire, or emit higher radiation levels than what a handset itself traditionally does?... I got an idea. How about swapping out a low battery for a fully-charged one? When will someone ever think of that?

posted on Jan 07, 2016, 12:01 AM 0

11. TyrionLannister unregistered

You still need to charge the battery if you want to swap that. This solution enables you to never ever charge your battery, unless you are super-lazy. I usually walk 7-8 KM a day. This kind of solution will enable me to even get away with a 1000 mAH battery in a phone.

posted on Jan 07, 2016, 1:27 AM 1

16. NoToFanboys

Posts: 3231; Member since: Oct 03, 2015

The next problem would be the battery's lifespan.

posted on Jan 07, 2016, 3:40 AM 2

14. LetsBeHonest

Posts: 1548; Member since: Jun 04, 2013

I got an idea. How about converting the heat energy that phone emits in to electricity then charge the phone? Nowadays phone do get pretty hot so might work right? At least helps to get batter battery backup right?

posted on Jan 07, 2016, 2:57 AM 3

19. Nathan_ingx

Posts: 4769; Member since: Mar 07, 2012

How about the converted energy be used to cool the phone? Lol.

posted on Jan 07, 2016, 4:21 AM 0

21. LetsBeHonest

Posts: 1548; Member since: Jun 04, 2013

Ha ha nice one lol. But still nice thought.

posted on Jan 07, 2016, 4:37 AM 0

22. TyrionLannister unregistered

You both should read about something called second law of thermodynamics.

posted on Jan 07, 2016, 5:14 AM 0

24. LetsBeHonest

Posts: 1548; Member since: Jun 04, 2013

Ohhh man.. You sounds like my old teacher. Lol:P

posted on Jan 07, 2016, 9:10 AM 0

23. talon95

Posts: 1000; Member since: Jul 31, 2012

First, if you're collecting the heat then you are already cooling the phone, and second, heat is just the wasted energy so that might be 40% of the input power but once you collect and convert it you'd only be putting like 10% of the initial power back into the battery. It's nice if it lives 10% longer but not if the phone is twice as thick to accomplish it. At that rate just start with a battery that is 3 times larger and fits in the same space as the fancy converter, and for less cost.

posted on Jan 07, 2016, 9:05 AM 0

25. Nathan_ingx

Posts: 4769; Member since: Mar 07, 2012

1. That was a joke 2. Relax!

posted on Jan 07, 2016, 9:47 AM 0

2. My1cent

Posts: 370; Member since: Jan 30, 2014

Yeah, yeah... Future is... what?

posted on Jan 07, 2016, 12:16 AM 1

15. Max_Boost

Posts: 101; Member since: Sep 22, 2012

2116. LOL

posted on Jan 07, 2016, 3:14 AM 1

3. Nathan_ingx

Posts: 4769; Member since: Mar 07, 2012

Asians...Asians everywhere! If this works out, m'a start jogging every morning.

posted on Jan 07, 2016, 12:21 AM 1

10. Hallyu

Posts: 790; Member since: Jul 21, 2015

Samsung is currently at the forefront of the development, and we will get a real deal pretty soon. Thanks to Samsung SDI and other relevant parties like LG Chem and Samheung Battery for this fantastic effort.

posted on Jan 07, 2016, 1:21 AM 0

4. Nathan_ingx

Posts: 4769; Member since: Mar 07, 2012

Well, this way, you keep yourself exercised and your phone charged at the same time (if it works exactly as planned. Edit: Reply meant for 1.Phonehome. (yikes!)

posted on Jan 07, 2016, 12:23 AM 0

5. pureviewuser

Posts: 501; Member since: Nov 11, 2012

Ideal for those into the five knuckle shuffle lol!!!!!!

posted on Jan 07, 2016, 12:24 AM 0

6. GreenMan

Posts: 2698; Member since: Nov 09, 2015

If it comes into production, it would be a flop in U.S, I'd bet. Okay, sure it converts mechanical energy into electrical one... BUT HOW DO YOU EXPECT COUCH POTATOES, THE LARGEST COMMUNITY WHO BUY THE LATEST AND GREATEST SMARTPHONE TO EXERCISE? The battery should charge while YAPPING & SWIPING... Or while SLEEPING. Or... You know... Being a couch potato. Or... How about they charge on CALORIES...? Or FARTS, for example? Just sayin'...

posted on Jan 07, 2016, 12:36 AM 4

7. TrevorB1

Posts: 64; Member since: Dec 30, 2015

Could I attach the phone to my pet and have them run around the yard for an hour? lol

posted on Jan 07, 2016, 12:44 AM 7

9. GreenMan

Posts: 2698; Member since: Nov 09, 2015

TrevorB1@ LOLz! Yes, it didn't occur to me. Man, you Americans might be lazy, but you're sure pretty smart! I had a good laugh reading this... You just made my day! Thanks...