The Next Notebook Battery? Lithium Polymer

Lewis Clarke writes "Sony is changing its course to use an old technology for its new battery manufacturing. ZDNet is reporting on comments from Sony Electronics President Stan Glasgow, where he said that Notebook makers will 'likely' soon choose to incorporate lithium polymer batteries (a battery technology that emerged nine years ago) over the current commonly used type, lithium ion batteries." From the article: "Lithium polymer batteries use lithium as an active ingredient. Lithium is a volatile material, but the lithium in these batteries isn't packed into cells as it is in lithium ion batteries. Instead, it is contained in a polymer gel. These gel batteries can't provide the same sort of energy density as lithium ion batteries, but that's now a plus."

Comments

A Better Idea

[value_added]

Why not use dilithium, instead?

Re:A Better Idea

[JabberWokky]

Hell, skip that and go straight to trilithium. If it's good enough for Romulan weaponry, it's good enough to power my laptop... which is placed on my lap... right over my genitals...

Okay, maybe we should rethink this whole battery thing and go back to luggables.

--
Evan

Kaboom?

[sam_paris]

Is it just me or do others start to feel nervous when Sony start trying to push new battery technology..?

Please go back to the drawing board...

[__aaclcg7560]

Less power and less bang for the buck? Can't wait for the marketing people to spin that one.

Lithium Polymer is already in use

[syncrotic]

High end notebooks from Dell, IBM, and possibly others all use lithium polymer batteries for their drivebay batteries, where space is extremely tight and the geometry is suboptimal for cylindrical cells. Li-polymer batteries can be made into very thin shapes and don't need a metal case to contain individual cells. Because of this, the energy density is actually higher. I think the reason they're not in widespread use is simply that they cost more.

Re:Lithium Polymer is already in use

[edmudama]

exactly.

Energy density of the raw charge storing material is lower with LiPo, but it doesn't require the same packaging/metal casing, so net energy density is higher.

Something like 2.5 times as much power per weight as Li-Ion battery packs. It's revolutionized RC electrics.

Models that were designed for NiMH cells and were getting 4-5 minutes of flight time, can now get 15 or more minutes of flight.

Bollocks.

[Control Group]

No, that's not "a plus." That's a cost-benefit tradeoff on the manufacturing side, and a risk-reward proposal on the end-user side. Lower energy density means either shorter battery life or heavier laptops. I don't think anyone would call either of those results a "plus." They're tradeoffs.

Moreover, there are plenty of Li-ion batteries out there that haven't overheated, burned, detonated, or imploded into naked singularities causing the annihilation of life as we know it. Which means, for those batteries, you get to have longer battery life or lighter laptops sans the death and destruction result, so the move from that state to the proposed solution isn't even a tradeoff, it's a pure loss.

Covering for the inadequacy of your manufacturing/QC processes by making a worse product that's easier to make doesn't translate into a "plus." It sounds to me that the real plus would be if they moved to a power source they've obviously got in plenty - though I think the name "spintronics" has already been taken.

Next Notebook Battery?

[bill_mcgonigle]

You mean "current notebook battery"?

I'm typing this on a c2d MacBook Pro which lists a lithium polymer battery as its spec. Third bullet line down on that page. I also have a 5GB iPod that uses a lithium polymer battery. Apple went Li-Ion for later iPods, probably for higher capactiy, but I'm on my second battery in 5 years and it gives me more than 8 hours of playtime (haven't tested it beyond that).

I guess that means Apple isn't using Sony for its current batteries?

Re:Eh?

[arth1]

I must be getting confused - I thought Lithium Polymer was better than Lithium Ion?

In some ways. It's the same thing, really, but packaged two different ways. Both are often called Li-Ion batteries, cause they are. The main two advantages of Lithium Polymer are:
(A) They can be shaped in all kinds of odd shapes, which is a benefit when you also pack some circuitry inside the battery package, or have to use space as best you can.
(B) They are less likely to explode, as there's resistance in the gel medium itself that hinders (if not completely prevents) a chain reaction.

The main downside to Li-Polymer is that it is less efficient by volume and weight.

Regards,
--
*Art

Be VERY careful

[IflyRC]

As my name implies I fly R/C aircraft as a hobby. Within the last few years electric powered models have really taken off. Most of this is due to the Li-Po battery. Lithium Polymer batteries are a subset of Lithium Ion batteries but the design of the cells are different.

Li-Po batteries are small and light and can produce a higher continue current than lithium ion. They are very powerful batteries.

One of the problems though...and why I generally stay away from them is that they explode. They can easily become unstable if dropped (or crashed). I don't claim to be an expert but the cells in a lithium ion battery are metal - they can sustain an impact and vibration where as the cells in a lithium polymer are mostly plastic which can cause a mix of the chemicals inside and cause the battery to heat up until it vents and then explodes.

Fire caused by overcharging

Video of a lipo battery going bad.

Re:Be VERY careful

[bughunter]

My job is building hi-rel batteries for launch vehicles and spacecraft, so let me share some facts that seem to be in confusion in this forum.

First, The distinction of Li-Poly from the general chemistry of Li-Ion is in the electrolyte. Instead of a liquid or gel electrolyte, the Li-Poly cell uses a thin sheet of conductive polymer doped with ionic compounds. Now while this polymer electrolyte has less mobility than a liquid, resulting in a lower energy density (J/cm^3) and power density (W/cm^3), in practice the manufactured shapes can be more complex than the coin or cylindrical shapes imposed by liquid electrolytes. Therefore more "battery cell" can be stuffed into otherwise unused volumes, and in many applications this maximizes the effective energy density beyond what can be achieved using cylindrical cells.

Second, any Lithium chemistry cell using a Cobalt-alloy cathode (virtually all of them on the market today) is subject to a thermal runaway condition if the internal cell temperature exceeds 130C. This includes Li-Poly cells.

Valence corp has patented a Lithium-Iron-Phosphate cathode chemistry that has less energy density, similar to NiCd, however the change to a Iron cathode eliminates the thermal runaway possiblity, making the cells much safer. These will soon be available commercially from DeWalt as battery packs for their cordless power tools. Here is a press release... note that Valence later bought the company referenced therein, A123 Systems. (I wonder if there's been a delay somewhere - DeWalt was marketing this much more heavily just a few months ago, now you have to do a search on their site to find any reference of it.)

Another company, Altair Nanotechnologies, has patented a Litium Titanate Spinel anode technology that also claims to eliminate the risk of fire and improve on both the Energy Density and Power Density of vanilla Li-Ion. However they have yet to actually deliver cells (to me anyway, despite many requests). And this chemistry is not exclusive to the Iron Phosphate cathode, meaning someone with all of the proper patent licenses could combine the two and make a high energy-density, non-exploding laptop battery that does even better than the Li-Poly battery I'm using in my MacBook Pro right now.

Finally, here's a link to the "Safety Concerns" page of the "Battery University" site which is an excellent user's reference for Li-Ion secondary batteries, among others. And here is a link to a Valence Corp white paper that describes their LIP cells. Lastly, here is a PDF of Altair Nano's marketing material describing their claims of safety advantages their Titanium spinel material offers to commercial batteries.

NOT TRUE

[IflyRC]

Actually Lipo are more likely to explode. Most Lipo battery cells contain plastic whereas lithium ion cells are metal.

Lipo battery warning for R/C aviation

I use both battery types in various aircraft. The lithium polymer is much less stable. I've seen a pack swell and be ready to vent just by knocking one off of a table onto the ground. Lithium ion will not do this. Also, keep in mind that any battery will explode if you overcharge it.

Re:NOT TRUE

[IflyRC]

True, its not a forceful explosion but the flames are so intense it wouldn't really matter (without the danger of shrapnel). NiMH and Nicad can explode as well but it takes a lot to get them to that point - usually overcharging. Lipos can go just from being dropped.

How many laptops do you see being dropped? Apparently there is enough lap top dropping that IBM was advertising how sturdy their laptops were a few years back.

Not sure about the weight thing.

[Kadin2048]

The main downside to Li-Polymer is that it is less efficient by volume and weight.

This, I think, is not true. LiIons may be more efficient by volume, but LiPos are almost certainly more efficient per weight, because they don't have the cells, or many of the protection mechanisms that LiIon batteries have to have.

The power/weight advantage is why they're used in applications where weight is more important than volume -- R/C aircraft, for instance. When LiPo batteries came out, they basically replaced NiCads and LiIon batteries overnight in most ultralight aircraft and helis, because they're just so much lighter (meaning that if you had an aircraft designed for NiCads, which wasn't atypical, you could get ridiculous flight time by upgrading to LiPoly cells).

But being more efficient per volume, that I could definitely believe.

The other big advantage I have heard is that with LiPo, you don't have to encase the batteries as heavily, so more of the weight and volume can actually be taken up with electricity-storing components, instead of as an 'exoskeleton' providing protection for the cells.

Re:lifetime?

[Rob the Bold]

has anything changed with this or is what i've heard BS?

You can design in a larger and more costly charger manager in a notebook battery than you can in a digital audio player. More sophisticated charge management ICs have dead battery precharging cycles, thermimstor inputs to watch cell temp, and smarter logic for charging battery depending on state of charge when you plug it in to the charger. The smaller, low cost chargers you use for small electronics aren't nearly so smart, most just stop charging at a given voltage (or at the end of the safety timeout).

Anyway, you can get better battery lifetime if you can afford the cost and size of a fancier charger. Doesn't mean the guys designing small devices are doing a bad job, they just have a different tradeoff to make when doing the design.