DOE to Award $60M to Support Transmission Planning for US Interconnection Networks
Valero And Mission NewEnergy Execute 5-year, US$3.5B Biodiesel Supply Agreement

Panasonic Starts Mass-Production of High-Capacity 3.1 Ah 18650 Li-ion Cells

Panasonic Corporation has developed an 18650-type high-capacity 3.1 Ah lithium-ion battery and began mass production of the battery this December. The new 3.1 Ah cell has a nickel cathode and an energy density of 675 Wh/L.

The company successfully achieved safety and higher capacity by using its Heat Resistance Layer (HRL) technology that forms an insulating metal oxide layer between the positive and negative electrodes. The layer prevents the battery from overheating even if a short circuit occurs.

Capitalizing on this technology, Panasonic commercialized a high-capacity 2.9 Ah lithium-ion battery with a nickel positive electrode (energy density: 620 Wh/L) in 2006. (Earlier post.)

Based on the cell construction with the nickel positive electrode and the HRL, the company added improvements to the battery and succeeded in developing the 3.1 Ah lithium-ion battery, currently the industry’s highest capacity in the 18650-type.

The new battery provides long-lasting power to laptops. This high energy density battery can also contribute to downsizing and weight reduction of portable devices. With adoption of the nickel positive electrode, the new rechargeable battery excels in durability in actual use and charge retention—the battery can be stored for a long period of time because of low self-discharge.

Panasonic will continue to refine its battery technology to deliver lithium-ion batteries combining safety with high capacity and use this technology to develop commercially viable green energy storage systems.

(Current model)
(new high-capacity model)
Capacity 2.9 Ah 3.1 Ah
Volumetric energy density 620 Wh/L 675 Wh/L
Mass approx. 44 g approx. 44.5 g
Voltage 3.6 V 3.6 V
Charging voltage 4.2 V 4.2 V
Capacity 10.4 Wh 11.2 Wh


Account Deleted

Now this is (1000/44.5)*11.2Wh = 252 Wh/kg! This is the highest energy density I have seen for any mass market and secondary cell (are you reading this clett?).

Tesla use 8000 of the 18650 cells to get a 70kWh battery for their 300 miles version of the Model S using about 0.233 kWh per mile.(1) If Tesla used this new cell from Panasonic they could make a (8000*11.2Wh=) 89.6 kWh battery and get a (89.6/0.233) = 384 miles range for the Model S.

No need for a noisy and polluting range extender. Fisker and GM should seriously consider making an all electric version of their Karma and Volt using this cell and Tesla’s safe packing technology for such cells.

1) Model S battery pack specifications:


Henrik: Your math is correct. The individual cell 251 Wh/Kg energy density will most probably drop betwen 200 to 225 Kw/Kg when assembled into larger battery packs. That is still higher than average packs and a good step towards 500 Wh/Kg.

Batteries energy density will reach 500+ Wh/Kg some time during the next decade. Simultaneously, durabilty and life cycles will increase to 4000+ and rate of charge/discharge will also multiply.

Electric vehicles will have e-range of 300 to 500 miles by 2020.

With all the resources being used worldwide for batterry development, many new chemistries and technologies will emerge, making current batteries look rather primitive.

State of the art, post 2020 batteries (with 1000+ Wh/Kg) will put an end to ICE for most vehicles. Electrified vehicles and HVAC will eliminate most oil imports and shortages, reduce pollution emissions and GHG.

ESStor may not have enough time to build and test its ultra capacitor before new ultra batteries come out with better performances. However, ultra capacitors with 1++ million cylcles may find applications in transmission lines leveling, solar and wind power systems, etc.


Uh before you get all wacky notice thier current cell is just slightly lower capcity then this one so it isnt that big of a leap forward specialy concidering how long it likely took to develope.


I'm not sure of the reason for all of the excitement. This is a 6% improvement over a 3yr old battery.
Laptop batteries have been using the 2006 formula for quite awhile:
Tesla could have used the 2006 battery if it had met all of their needs.

The bigger news might be in the safety improvements


With Panasonic's recent purchase of Sanyo - the volume will drive down cost faster. From the reaction of the Lockheed mass storage people recently - it seems likely that eeStor actually has something that they will sell for large scale storage. No mention of transport apps.

Either way, the transition to EVs will go faster than most projections once consumers realize the convenience of not stopping to fill a gas tank in most daily use.

The wild card remains - can we afford this reletively slow adoption of electrification. As opposed to introduction of disruptive technologies that would obsolete even eeStor.


Every article about battery development brings out comments from “Eestor nuts”. Would Zillions of dollars be spent on battery and ultra capacitors research and development if the people in the know would believe that Eestor is anything more than vapor ware?


I can see the advantage of the Nissan Leaf battery concept where the owner leases it and will be able to upgrade as better technology arrives.


What is the cycle life of this battery? If not any better than ">500" advertised for other panasonic 18650s then I'm not excited. It is nice to see an example of increasing Li Ion energy density though.


Happy Holidays from a loyal GCC commenter to the other loyal GCC commenters!!!

To My Democratic Friends: Please accept with no obligation, implied or implicit, my best wishes for an environmentally conscious, socially responsible, low-stress, non-addictive, gender-neutral celebration of the winter solstice holiday, practiced within the most enjoyable traditions of the religious persuasion of your choice, or secular practices of your choice, with respect for the religious/secular persuasion and/or traditions of others, or their choice not to practice religious or secular traditions at all. I also wish you a fiscally successful, personally fulfilling and medically uncomplicated recognition of the onset of the generally accepted calendar year 2010, but not without due respect for the calendars of choice of other cultures whose contributions to society have helped make America great. Not to imply that America is necessarily greater than any other country nor the only America in the Western Hemisphere . Also, this wish is made without regard to the race, creed, color, age, physical ability, religious faith or sexual preference of the wish.

To My Republican Friends: Merry Christmas and a Happy New Year in the year of our Lord Jesus Christ 2010.



Please keep your attempts at political humor to yourself.
And oh by the way, Happy Holidays to you too.


ejj - A Merry Xmas to you too. May 2010 be a most enlightening year for you and your friends.

Henry Gibson

If your average trip is only 20 km there is a wasted high capital expense to have a very heavy battery that can give you 100 km. A diesel range extender does not have to be noisy and a turbine could be less noisy and neither would have to be very big. A ZEBRA battery fully packaged has had about 200 watt-hours per kilogram for many years and needs only air blown through it for cooling in any climate, and its automobile life is 10 years and it can be used for UPS or HOME-TO-GRID operation for many more years after that. It uses only a small amount of nickel and cheap aluminum, steel and salt. For many cars a range of 20 km with a range extender would never use the range extender. ..HG..


Hi Henrik, you're right I am excited about this! Tesla are currently using cells of 173 Wh/kg at the cell level, so these new ones could improve range by 45%! Probably don't have the power or cycle capability Tesla need however....

252 Wh/kg is the best on the market as far as I'm aware. However, Panasonic may still have some more up their sleeve, as a vanadium doped cell they were recently developing was meant to have 3,600 mAh per 18650 cell!


Why don't they make larger cells?

Why not double the diameter and perhaps height?

Using 8000 of them in a battery pack sounds like a crazy solution to me - if each battery had 8x the capacity, you would only need 1000 which is still a lot, but nothing like 8000 connections (or connection pairs).

Also, how many cycles?

At one level this is great, at another, it suggests that Lion cells are a mature technology and that it is plateauing out.


As mds said thier older cell had only 500 cycle and so this likely also has around 500 cycle lifespan thats why it was never used for the tesla and wont be.


They are using this cell size because they could pump it straight into their existing manufacturing line. They stated that their strategy was to get to market with mass production this way and be able to beat everyone else on price in the short term.

This has nothing to do with the technology being plateaued. They are not trying to do anything that will slow them down from this short term goal for this production line. The 18650 is a silly form factor for electric vehicles. It requires huge numbers of interconnects, specialized cooling systems, packaging and overhead for each cell and simply lots of weight for the wiring itself.
It's a simple gamble that they can grab some market share short term.

Of course, they are looking at other technology and larger cells along with everyone else for further down the road.



Are you happy with you laptop battery ? imagine one second if you had to deal with the same problems with your car , right ... you also see a future for EESTOR in your cristal ball ? maybe you should buy a new one then...


I wonder why they standardize on the 18650 format except for other applications. It seems like the smart thing to do to offer larger format batteries. We know what happened to the EV-95 NiMH batteries, but there should be no such restrictions here.


Tree... I sometime use a relatively low performance (I'm not a gamer) ultra low power consumption laptop with an oversized 8-cell battery. Each charge could last over 10 hours but I plug it in after 4 to 6 hours at most. No new battery was needed to date.

There are about half a dozen such laptop on the market i.e. the Micro Star Intl (MSI) x-Slim 340 has it all. Apple, ASUS and others also have interesting units

The trick may be to use an ultra low power consumption unit with a larger (90 to 100 Whr, 8 or 12 cells) battery.

I must admit that I use the desk top with its 24-inch screen much more often.

Henry Gibson

Yes, batteries that can be used cheaply in plug-in-hybrid cars can be of benefit. One such battery was invented almost 200 years ago. The lead acid battery. Firefly and others have already shown that the weight and cost per cycle of lead batteries can be vastly improved.

Lithium ion batteries that can take a high performance vehicle on a 300 mile trip is bad engineering and economics for most uses of automobiles.

Import of fuels can be reduced to zero by making methanol produced from coal and waste the standard liquid fuel. Actually n-butanol would be better. Plug-in-hybrid cars could then use these compact low weight liquid fuels for long trips.

Remembering always that humans have over 3000 natural built in potassium nuclear explosions every second, and that radioactivity from nuclear power plants cannot even add a significant increase to this built in radio-activity, nuclear power plants can free up coal and natural gas to be used to power automobiles and planes. Eventually nuclear power plants can use captured CO2 to make into liquid fuels.


Is there a good reason to make cells larger than 18650?

Thermal considerations argue for smaller size.


Unfortunately, there is a huge difference in the application & construction of Li cells.
Nowhere in this article does it say the application is for EVs or HEVs. These NCR18650A cells are "power cells", not energy cells and have an internal resistance of ~60 milliohms which makes them useless for EV applications unless many are paralleled. The high heat loss due to this resistance creates an expensive thermal management issue that has to be financed.

The comments to this entry are closed.