Better Lithium-Ion Batteries Are On The Way From Berkeley Lab

[OKIsItJustMe]

(Moderators, please note, this is a press release from a US Government lab.—Copyright concerns are nil.)

http://newscenter.lbl.gov/news-releases/2011/09/23/better-li-ion-batteries/

Better Lithium-Ion Batteries Are On The Way From Berkeley Lab

A revolutionary conducting polymer enables the use of low-cost, high-energy silicon for the next generation of lithium-ion battery anodes

September 23, 2011
Paul Preuss 510-486-6249 [e-mail]

Lithium-ion batteries are everywhere, in smart phones, laptops, an array of other consumer electronics, and the newest electric cars. Good as they are, they could be much better, especially when it comes to lowering the cost and extending the range of electric cars. To do that, batteries need to store a lot more energy.

At left, the traditional approach to composite anodes using silicon (blue spheres) for higher energy capacity has a polymer binder such as PVDF (light brown) plus added particles of carbon to conduct electricity (dark brown spheres). Silicon swells and shrinks while acquiring and releasing lithium ions, and repeated swelling and shrinking eventually break contacts among the conducting carbon particles. At right, the new Berkeley Lab polymer (purple) is itself conductive and continues to bind tightly to the silicon particles despite repeated swelling and shrinking.

The anode is a critical component for storing energy in lithium-ion batteries. A team of scientists at the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) has designed a new kind of anode that can absorb eight times the lithium of current designs, and has maintained its greatly increased energy capacity after over a year of testing and many hundreds of charge-discharge cycles.

The secret is a tailored polymer that conducts electricity and binds closely to lithium-storing silicon particles, even as they expand to more than three times their volume during charging and then shrink again during discharge. The new anodes are made from low-cost materials, compatible with standard lithium-battery manufacturing technologies. The research team reports its findings in Advanced Materials, now available online.

High-capacity expansion

“High-capacity lithium-ion anode materials have always confronted the challenge of volume change – swelling – when electrodes absorb lithium,” says Gao Liu of Berkeley Lab’s Environmental Energy Technologies Division (EETD), a member of the BATT program (Batteries for Advanced Transportation Technologies) managed by the Lab and supported by DOE’s Office of Vehicle Technologies.

Says Liu, “Most of today’s lithium-ion batteries have anodes made of graphite, which is electrically conducting and expands only modestly when housing the ions between its graphene layers. Silicon can store 10 times more – it has by far the highest capacity among lithium-ion storage materials – but it swells to more than three times its volume when fully charged.”

This kind of swelling quickly breaks the electrical contacts in the anode, so researchers have concentrated on finding other ways to use silicon while maintaining anode conductivity. Many approaches have been proposed; some are prohibitively costly.

…

The icing on the anode cake is that the new PF-based anode is not only superior but economical. “Using commercial silicon particles and without any conductive additive, our composite anode exhibits the best performance so far,” says Gao Liu. “The whole manufacturing process is low cost and compatible with established manufacturing technologies. The commercial value of the polymer has already been recognized by major companies, and its possible applications extend beyond silicon anodes.”

Anodes are a key component of lithium-ion battery technology, but far from the only challenge. Already the research collaboration is pushing to the next step, studying other battery components including cathodes.

…

http://onlinelibrary.wiley.com/doi/10.1002/adma.201102421/abstract

[DirkGently]

1. Interesting!

[RC]

2. Cheaper to make, more expensive to buy.

Just wait. AA and AAA will cost another dollar or two more per 4 pak when these hit the market.

[OKIsItJustMe]

3. You know what? They’ll be worth more

I’d pay more for a rechargeable cell with an indefinite life span…

[kristopher]

4. And that is only while it is the new kid on the block

There are at least half a dozen feasible technologies in the pipeline that are going to advance battery storage dramatically.

New advances always command high prices but with commodities like batteries or solar panels, it is ultimately the price of manufacture that sets the retail price.

All previous timelines, even from as recent as 5 years ago, for deployment of products (like EVs or home storage) that depend on battery storage are being rendered obsolete by the advances we are seeing. It is more of an flood of advancement than a trickle or a flow (IMO of course).

[TheWraith]

5. These have nothing to do with AA and AAA batteries. This is about Lithium Ion.

The kinds of batteries used for laptops, phones, and electric vehicles.

[OKIsItJustMe]

6. Um… Lithium Ion cells also come in AA and AAA sizes

http://www.google.com/search?q=lithium+ion+AA

On the other hand, you shouldn’t use them as a replacement for a standard alkaline “http://en.wikipedia.org/wiki/Battery_%28electricity%29#Dry_cell">dry-cell.”

[TheWraith]

7. No, they're not. Some of them come in similar sizes, which have nothing to do with AA or AAA batts.

The fact that some retailers describe them that way only shows that some retailers have no clue what they're selling, as Lithium Ion batteries are completely incompatible with conventional AA and AAA batteries.

[OKIsItJustMe]

8. I believed you’ve confused size with formulation

AA and AAA are simply standard cell sizes:
http://en.wikipedia.org/wiki/List_of_battery_sizes#Common_consumer_batteries

A AA cell (for example) is 14.5mm x 50.5mm

A AA NiCd cell is not the same formulation as a AA Alkaline cell, nor does it deliver the same voltage (although they’re close.) A AA Lithium-Ion cell, on the other hand would deliver about 3x the voltage.

[txlibdem]

9. And each needs a specific type of charger in order to recharge it - do not mix them up!

The results will range from a dead battery or charger to an explosion and fire... so let's be careful out there folks.