Here's why a lithium battery degrades and loses capacity over time

Here's why a lithium battery degrades and loses capacity over time
Lithium-based batteries – the kind of which are used in pretty much every modern cell phone – don't last forever. About a fifth of a cell's charge capacity is lost by the time its 500th charge cycle is reached, and, unfortunately, there's nothing you can do about it. Chances are, however, that one day we will have more durable, longer-lasting batteries inside our gadgets, and a recent study conducted by the Pacific Northwest National Laboratory may make this day arrive sooner.

Using a powerful microscope, a team of scientists at the lab have made it possible to observe a lithium battery in real time as it charged and discharged. What they found was that the stress caused by the battery being used was causing cracks to develop on the electrode. This, however, is just one of the reasons why a lithium battery's performance decreases over time. As the research showed, each charge and discharge cycle leaves traces of lithium outside of the cell's electrode. This "dead" lithium, as the scientists refer to it, could not contribute to a future charge and was causing the battery's energy capacity to diminish. Furthermore, it was observed how a layer of solid-electrolyte interphase formed on the electrode's surface, thus "clogging" the battery and hindering its ability to take charge.

Using alternatives to lithium could be a solution to the problem. Metals like magnesium, aluminium, or copper could one day serve as a substitute that is both cheaper and more reliable, but at this time, more research into non-lithium rechargeable batteries is needed if they're ever to reach the performance of existing lithium-based solutions.

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1. GoBears

Posts: 456; Member since: Apr 27, 2012

Hell, I'd be happy if manufacturers stopped worrying about how thin the devices are and started stuffing in beefier user replaceable batteries.

3. elitewolverine

Posts: 5192; Member since: Oct 28, 2013

To me the thickness of the 930 is perfect. It feels so solid and like im holding something of value. 9mm to me is that sweet spot i guess.

10. QWERTYslider unregistered

Agreed. Only an idiot buys a phone without a user replaceable battery.

11. bendgate unregistered

So are you trying to say that about half of the smartphone users in the world are idiots?

13. tacarat

Posts: 854; Member since: Apr 22, 2013

Shortsighted might be better.

14. singhkaran9830 unregistered

Ignore him.Almost in every samsung article I have seen him crying only for one reason "Only an idiot buys a phone without a user replaceable battery."

19. corporateJP

Posts: 2458; Member since: Nov 28, 2009

Dude's got a point. To each their own, but I'd never buy a $700 flagship with everything built in. S5 is 10x better than their "upgraded" offerings. The Apple bashers from the Samsung camp need to STFU, you're on the same playing field now...

20. almostdone

Posts: 449; Member since: Sep 25, 2012

S6 battery replaced by Samsung = $49.99 S5 battery replaced = $29.99 $20 is not the end of the world! And this is only required if your battery has degraded significantly.

23. ibend

Posts: 6747; Member since: Sep 30, 2014

its cheap compared to their price.. and AFAIK samsung's battery is really durable (my s3 battery life still sit around 8H), and by the time battery life weared much, people will consider buying new flagship..

24. psychok9

Posts: 43; Member since: Jul 06, 2014

Isn't true and it depends of much you use it. 500 cycles aren't enough, especially if you need to recharge 2times/day because the battery is small. Lithium battery ruins fast and I dont want be forced to change smartphone if the other components are ok.

17. psychok9

Posts: 43; Member since: Jul 06, 2014

They care abot money, than they prefer not-replaceable battery ;-)))

21. Stuntman

Posts: 843; Member since: Aug 01, 2011

Agreed. I actually replaced my battery last year with a bigger and thicker battery. I'm glad my phone (Galaxy S3) has a removable battery feature. The bigger battery has a different back plate which makes the phone thicker. I happen to like the added thickness as it protects the camera better and provides clearance to the speaker.

22. Slammer

Posts: 1515; Member since: Jun 03, 2010

Radio Shack's closings in my area have landed me 75% off everything in the stores. I was able to pick up an extended battery for my wife's S3 for $10 and an extended for my s4 for $12. With tax, two batteries for $25. Even though it is a one time deal, there are sites on the web to grab replacement batteries for a great price. While they might be third party batteries, the goal is allowing us to replace these batteries for cheap until the contracts are up. This is the beauty of removable. John B.

2. Simona unregistered

I was thinking why manufs. don't make solar panels on back of phone and even around the screen..

4. elitewolverine

Posts: 5192; Member since: Oct 28, 2013

I wonder if people would accept a 720p screen with a resolution of 2k, but the 'dead' pixels were instead photo cells to recharge. This way the photocells are protected and can be used without facing the screen down.

5. buccob

Posts: 2977; Member since: Jun 19, 2012

No need for the later... Transparent solar cells has recently been invented and I assume it won't be long for someone to implement it on a phone

8. Nick_T

Posts: 186; Member since: May 27, 2011

There have been such phones. If you search for "solar" you'll find a few articles about them here on the site. Unfortunately, current solar cells produce too little power to justify the effort of putting them on a smartphone. Besides, leaving a phone out in the sun isn't a good idea.

9. Tanujtiwari

Posts: 84; Member since: Mar 18, 2015

You are my favourite reviewer nick!

12. mixedfish

Posts: 1562; Member since: Nov 17, 2013

What does that solve? Solar panels constantly charging the battery simple wears it out faster.

15. medtxa

Posts: 1655; Member since: Jun 02, 2014

not enough power, all day solar charging only for 10 minutes video?

6. Simion_Florin

Posts: 2; Member since: Apr 19, 2015

10 or 11mm for me on a 5 inch screen 1080p max, with a battery of 4000 mAh, it's just perfect.

7. hound.master

Posts: 1044; Member since: Feb 27, 2015

I'd prefer a better battery over thinness of a phone i don't really think a phone below 8mm is enough durable for now. And building a phone with solar panel is stupid cause your not always in sun and it's not durable at all although solar charging station is a good idea.

16. TheGunnyPT

Posts: 252; Member since: Feb 12, 2015


18. Slammer

Posts: 1515; Member since: Jun 03, 2010

Nick, thank you once again for sharing the basic principles of the battery technology that the manufacturers want the consumers to forget about. I often catch hell on these sites for my constant rants on this subject. However, I have not limited my knowledge or experience to just these sites. I have extended my concerns of imbedding the battery far beyond these limitations. I feel the battery technology has not progressed far enough to eliminate easy accessibility for the average consumer. Wireless charging is being instituted as a supplement but is not a very efficient form of charging and is actually frowned upon by engineers, scientists and technicians due to the premature damage it can cause to these batteries. And while you may continue to bring the fickle state of these batteries to the forefront, we will have people on these sites decline the common sense that retaining accessibility is very important to ensure consumer friendly service. We can agree that corporations want to make money. But, are we as tech enthusiasts, willing to let manufacturers do it this way? Or are we going to remove our mind straps and let the manufacturers know that embedded batteries are not ready for prime time yet for inexpensive service, down time and inconvenience of a $900+ phone? John B.

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