Feeds

Boffins builds lithium battery that can't explode

Solution: get rid of the metallic lithium

3 Big data security analytics techniques

Scientists from Stanford University in the US have worked out how to build a lithium-sulphur battery that doesn't require a lithium metal electrode. That, they say, will make it free from the "serious safety issues" that have been holding the technology back.

Lithium-sulphur is seen as a strong contender for the next generation of rechargeable batteries because it can support an energy density far in excess of lithium-ion technology. The upshot: batteries can be made smaller and still support a higher capacity than li-ion equivalents. They're also made from cheaper and less toxic materials.

According to the team - Yuan Yang, Matthew T McDowell, Ariel Jackson, Judy J Cha, Seung Sae Hong and Yi Cu - their lithium metal free battery yields a theoretical specific energy of 1550Wh/kg, four times the 410Wh/kg theoretical specific energy of lithium-ion batteries with lithium-cobalt cathodes.

Stanford Lithium-Sulphur battery design

The Stanford battery design

One downside of lithium-sulphur battery design has been the construction of the battery negative electrode. Cathode designs have used lithium metal to help ensure the electrode has sufficient charge capacity. But lithium metal has a tendency to form tree-like crystal structures which can penetrate the the polymer material used to separate the battery's cathode from the positive electrode.

If that happens, the battery short-circuits and that can have literally explosive results.

The Stanford team builds on earlier work in the creation of "mesoporous carbon" electrodes. These are made from tiny, porous carbon rods into which liquid sulphur can be made to flow by capillary action. This key discovery ensures a very good electrical contact between carbon and sulfur, essential to make a workable lithium-sulfur battery design.

However, instead of the troublesome lithium metal, the boffins used lithium sulphide - Li2S - which doesn't promote the formation of battery breaking crystals.

The scientists said they had achieved a discharge specific energy of 630Wh/kg, 80 per cent higher than a typical lithium-ion battery can manage.

But problems remain. The biggest hurdle is the low charge-recharge cycle count: after five discharge and recharge cycles, the Stanford battery's capacity has fallen by two-thirds. After between 40 and 50 cycles, the battery stops holding any charge at all. ®

SANS - Survey on application security programs

More from The Register

next story
Samsung Galaxy S5 fingerprint scanner hacked in just 4 DAYS
Sammy's newbie cooked slower than iPhone, also costs more to build
US mobile firms cave on kill switch, agree to install anti-theft code
Slow and kludgy rollout will protect corporate profits
Leaked pics show EMBIGGENED iPhone 6 screen
Fat-fingered fanbois rejoice over Chinternet snaps
Microsoft lobs pre-release Windows Phone 8.1 at devs who dare
App makers can load it before anyone else, but if they do they're stuck with it
Oh no, Joe: WinPhone users already griping over 8.1 mega-update
Hang on. Which bit of Developer Preview don't you understand?
Report: Apple seeking to raise iPhone 6 price by a HUNDRED BUCKS
'Well, that 5c experiment didn't go so well – let's try the other direction'
Feast your PUNY eyes on highest resolution phone display EVER
Too much pixel dust for your strained eyeballs to handle
Rounded corners? Pah! Amazon's '3D phone has eye-tracking tech'
Now THAT'S what we call a proper new feature
Hearthstone: Heroes of Warcraft – A jolly little war for lunchtime
Free-to-play WoW turn-based game when you have 20 minutes to kill
Zucker punched: Google gobbles Facebook-wooed Titan Aerospace
Up, up and away in my beautiful balloon flying broadband-bot
prev story

Whitepapers

Top three mobile application threats
Learn about three of the top mobile application security threats facing businesses today and recommendations on how to mitigate the risk.
Combat fraud and increase customer satisfaction
Based on their experience using HP ArcSight Enterprise Security Manager for IT security operations, Finansbank moved to HP ArcSight ESM for fraud management.
The benefits of software based PBX
Why you should break free from your proprietary PBX and how to leverage your existing server hardware.
Five 3D headsets to be won!
We were so impressed by the Durovis Dive headset we’ve asked the company to give some away to Reg readers.
SANS - Survey on application security programs
In this whitepaper learn about the state of application security programs and practices of 488 surveyed respondents, and discover how mature and effective these programs are.