## Panasonic Develops New Higher-Capacity 18650 Li-Ion Cells; Application of Silicon-based Alloy in Anode

##### 25 December 2009

Panasonic Corporation announced the development of two new 18650-type (18 mm in diameter, 65 mm in height) high-capacity lithium-ion battery cells for use in laptop computers and in energy applications including electric vehicles.

The newly-developed high-capacity 3.4 Ah and 4.0 Ah lithium-ion battery cells have an improved nickel-based positive electrode (Panasonic’s proprietary positive electrode material based on LiNiO2, allowing for high capacity and durability). The 4.0 Ah cell uses a silicon-based alloy for the negative electrode instead of carbon, and offers a volumetric energy density of 800 Wh/L, compared to the 620 Wh/L in the current 2.9 Ah cells.

In October, Panasonic Corporation announced a 1.5 kWh battery module from 18650-type (18 mm in diameter x 65 mm in length) lithium-ion battery cells to provide energy storage solutions for a wide range applications. Multiple units can be connected in series and/or parallel to store energy generated by home-use photovoltaic (PV) systems and fuel cells or power electric vehicles (EV). (Earlier post.)

The 3.4 Ah cell offers 20% greater capacity than the current 2.9 Ah model. The 3.4 Ah cell will be mass-produced in fiscal 2012 ending in March 2012. The 4.0 Ah cell, which has 30% greater capacity compared to the 2.9 Ah cell, will be mass produced in fiscal 2013 ending in March 2013. These high-capacity battery cells can be used to build high-energy battery modules.

Panasonic holds 337 patents in Japan and 136 in other countries including pending applications on the new battery cells.

Panasonic 18650 Li-ion Cells
2.9 Ah (current)3.4 Ah (FY 2012)4.0Ah (FY 2013)
Cathode Nickel Enhanced nickel Enhanced nickel
Anode Carbon Carbon Silicon
Capacity 2.9 Ah 3.4 Ah 4.0 Ah
Avg. discharge voltage 3.6 V 3.6 V 3.4 V
Mass Approx. 44g Approx. 46g Approx. 54g
Energy capacity 10.4 Wh 12.2 Wh 13.6 Wh
Vol. energy density 620 Wh/L 730 Wh/L 800 Wh/l
Charging voltage 4.2 V 4.2 V 4.2 V

Direct Methanol Fuel Cell. Panasonic also announced it has developed a direct methanol fuel cell system which can produce an average power output of 20 W by increasing the output per cubic centimeter twice that of its previous prototype. Using this technology, Panasonic aims to develop a 100 W-class portable generator and start field testing in fiscal 2012 ending in March 2012.

In 2008 Panasonic developed compact fuel cell stacks by reviewing the structure of its connecting parts. It also developed compact and energy-efficient balance of plant (BOP) systems including a fuel supply pump that can directly mix and adjust the concentration of methanol internally. By improving the stack technology, Panasonic has successfully doubled the average power output to 20 W while retaining the same volume with the preceding prototype. The high output methanol fuel cell allows for powering feature-laden laptop computers, which have relatively high power consumption.

The new fuel cell system also boasts 5,000 hours of durability (based on eight-hour intermittent use per day). Durability was a major challenge for commercialization of fuel cells because power output drops as the electrodes deteriorate. Panasonic solved the problem by developing a technology that enables supplying high concentration fuel to the electrode.

Using micro porous layers that control the amount of fuel passing through them, this technology enables supplying highly concentrated fuel to the electrode and suppressing methanol "cross-over" which wastes fuel.

Panasonic holds 139 patents in Japan and 69 in other countries including pending applications on the fuel cell system.

### Comments

Heh anyone else notice the high power battery weighs almost 25% more so it is only slightly better wh/k then the old design? Better wh/l tho thats for sure.

The 3.4 Ah cells are 265 Wh/kg.

If you replaced all the cells in a Tesla roadster with these (they are the same size and format), you could increase battery capacity by 57% from 53 kWh to 83 kWh.

A changeover to the new cells would also increase range from 244 miles (current EPA estimate) to 383 miles.

"..5,000 hours of durability.."

If they can develop larger, more efficient and more cost effective DMFCs, that would solve a LOT of problems with transportation. An EV with some batteries AND a range extending DMFC could run on M100 at $2 per gallon and get 60 mpg. @Clett, I hope they give us the option of reducing the weight and keeping the 244mile range. Can you imagine how well the Roadster would handle if you reduced the battery pack from 450kg down to 193kg...and took the extra batteries off the top area of the existing battery pack so the center of gravity for the vehicle was even lower? Better acceleration and handling as well. It least it would be nice to have the option of the lighter pack vs the extra miles for those of us who don't need that kind of range. I never drive more than 100 miles in a day. I wonder how much these cells will cost? Tesla’s Model S use 8000 of these 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 the 3.4A cell from Panasonic they could make a (8000*12.2Wh=) 97.6 kWh battery and get a (97.6/0.233) = 418 miles range for the Model S. That is enough for 6 hours of non-stop driving at 70 mph. That will probably cover 100% of the travel needed by 99% of all potential private car owners. In my opinion the emergence of this kind of batteries will make a very large part of the high end vehicle market go pure electric in order to avoid the inconvenience of fueling at public gas stations and in order to avoid the noise and vibrations that follow with internal combustion engines. References: 1) Model S battery pack specifications: http://www.autobloggreen.com/2009/03/26/tesla-model-s-50-000-ev-sedan-seats-seven-300-mile-range-0-6/ It is still crazy to use this size battery in EVs. It is fine for laptops, but EVs need 4x or 8x larger cells [IMHO]. + even if you have a range of 400miles, it till take a long time to charge up 98 KwH - while you can put 80L into a diesel in 5 minutes. It is certainly progress (and to be applauded), but it is evolution, not revolution. Ever since "pay at the pump" (with credit card) people have not had to go inside of gas stations (you used to have to walk inside to pay). If it takes 20 minutes to recharge your EV you'll have to kill some time. I would think the gas stations would love this and readily make chargers available. It is dwell time that costs. You want people in an out leaving money every five minutes. They would have to charge you for that instead of turning over several customers in the same time. @SJC Wouldn't it be better to have some dwell time as long as there was an available "charge cord" available for other customers to use? I would think they would have to be making more money if people also came inside and bought something while they waited for the charge. Of course, if they are blocking all the charging stations that is clearly a bad thing and a 20 minute charge makes that much more likely. Dave the problem is charging doesnt net much in profits and takes quite a bit more time. And no just because they have time to kill doesnt mean anyone will go in and buy anything far more likely they will sit and listen to music. Also remember they dont tell us what the lifespan of the various batteries are nor do we know how durable they are in bev use. Some of them may only be suitable for milder usage patterns such as hybrids and stop start micro hybrids. SJC said, "It is dwell time that costs. You want people in an out leaving money every five minutes. They would have to charge you for that instead of turning over several customers in the same time." Wrong - they absolutely want you IN the store. They make nearly nothing on the sale of fuel and rely upon sales of goods inside their stores (or sales of maintenance) for profits. I would imagine the sales of electricity would follow nearly the same model except a large battery pack means you spend more time in the store and are more likely to buy a coffee or soda (which they pay maybe$0.08 to $0.18 cents out of pocket and earn$1 to $2 in revenue). It looks like convenience stores don't get their profit from fuel sales. These 2008 numbers from the National Association of Convenience Stores: "only 31.7 percent of all profit dollars came from fuel sales, NACS said." And this despite the fact that fuel accounted for the majority of their total revenue: "Industry sales jumped 8.1 percent to reach$624.1 billion, with both motor fuels sales (up 10.1 percent to $450.2 billion) and in-store sales (up 3.2 percent to$173.9 billion) showing growth."

http://www.moderncarcare.com/hotnews/convenience-store-sales-profits-show-gains.html

So if fuel is 72% of sales but only 31.7% of profit...then I assume they are living on profits from in-store sales. I don't know if longer dwell time will improve this number but I don't see how it could hurt.

@DaveD:
How about we tow the Tesla roadster to the track with just enough quick discharge and fast re-charge batteries to drive about 20 miles at wide open power; three sessions for practice, qualifying and the race, with charges in between. How much lightness would that add?

Patrick, I did not know you had the absolute wisdom of God, you must be so pleased...

Sorry SJC but Patrick is right: A station owner will make more profit selling you a can of pop than he will selling you a tank of gas.

However you are also right in that he doesn't want you dwelling at the pumps themselves. Fuel pumps cost a lot of money and refueling islands take up a lot of the limited space so they are a bottleneck.

Also unlike gas pumps where you can wait in a line you cant possibly be willing to wait in a 4 deep line at a charge station;/ An as such you wont bother to stop there and thus wont be buying anything anyway.

You have to stop thinking of recharging your car in the gas station model; think of it in the destination model. You go somewhere on the charge you have from home, park/plug-in and do what you have to do while it's recharging. Gas stations have had to become convenience stores to stay profitable but with EVs it will be the other way around; convenience stores will become recharging stations. You wont be waiting in line because the whole parking lot will have charging posts; the parkingmeters on the streets will have plugs, etc.

If you are going on a long trip it's simpler to use gas station as gas stations: The only difference is if you're driving a BEV you'll be gasing up the genset trailer hitched to the back.

BTW there's this guy who E-biked across Canada; http://hackaday.com/2009/08/19/e-bike-across-canada-for-10/
He had no problem finding places to recharge.

You guys can wait in line to recharge at Exxon, I am going to go to one of the 20 recharge stations each McDonalds will have along every interstate location. I plug in my car for 11 cents a kWh, about 1 cent more than the local price, and I go inside and get a meal and a shake. By the time I am finished 30 minutes later, my car has more than half a charge. Since it would take nearly an hour to get the last half, I take off knowing that there are McDonalds everywhere, and if I get truly desperate, an Exxon/Shell station.

I think ai vin and ziv are right, the model will completely change. Today's convenience stores evolved because gas stations needed to make more profit.

As EVs volumes get large, most McDonald's, Starbucks, malls, etc will have charging stations and we'll be topping off while we do normal errands.

The interstate convenience store will continue to evolve the way it's already going: Fast food restaurants built inside the stores. I've noticed that a large number of the new ones already have a McDonald's, Wendy's, Pizza Hut or something inside.

You're right ai vin, we're thinking about it the wrong way. The current system evolved because of gas. EVs don't need to fit that same system because a new one will evolve to fit them.

This is why I am so upset about our own DOE in the purchase of some 5000 Nissan Leafs.

City businesses and charging stations will evolve as will interstate convenience stores in ways that no one cannot predict – each step will be affected by the previous step and the changing environment over the next 20 years.

Is the DOE wasting billions of their dollars playing Simcity?.

No.

They are playing with and wasting OUR money.

@Lad,
I was thinking the same thing. The Isle of Man race next year is supposed to add a vehicle for 4 wheel EVs next year in addition to the motorcycle category.

That's a 32 mile track so imagine a Roadster with these new Panasonic batteries in it. Assuming you'd need a 20kWh pack for racing the 32 miles (just an off the cuff guess) and you'd have a Tesla who dropped from a curb weight of 2690 lbs down to 1867 lbs...AND you could lower the center of gravity because the current stack is pretty tall.

That 31% drop in weight would do some interesting things considering the current car does 0-60 in about 4 seconds. And imagine the improvements in handling.

This is very good news. Once Toyota comes out with their plug in hybrid, I am sure that they will use these batteries to lower the weight of the battery pack and/or increase the all electric range. Ford and GM...watch out.

New technology requires new ways of think. ICEVs required service stations to supply their GOjuice. They were called service stations because they used to give you free customer services(like window washing) with your fill-up to make you want to come back. With BEVs the GOjuice will be supplied as a customer service.

Patrick and ai_vin, no one KNOWS but everyone expresses an opinion. Unless you have numbers supporting the volume and margins of stores associated with gasoline filling stations and you KNOW the real profit margin of gasoline you are just guessing and expressing an uninformed opinion of what you think is the case.

So am I, but as long as we are going on observation, when I go into those stores I seldom see people loitering for 20 minutes and standing in line to buy overpriced items. They do good business, but if every person's car is sitting in front of a pump with a full tank, I KNOW that I am not making any money on that pump selling gasoline.

They put stores in because there had to be someone there and they might as well be doing something to make more money. Some filling stations might make more money on donuts than fuel, but that is not the main reason. They also have car washes, but I doubt that they make more money on those than selling gasoline. I know when I see a tanker truck there they are filling tanks for quite a while, so they must be selling some gasoline.

There is no sense arguing about something that none of us KNOWS about, that is idiocy. I am just expressing how I would run my gasoline/charging station. That would be an operations plan developed by studying the numbers and formulating an optimal plan designed to make the most money. I certainly would not create that plan from reading people online.

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