Batteries and New Battery Technologies

Leaf modules are discussed here
http://endless-sphere.com/forums/viewtopic.php?f=14&t=52162&p=966084&hilit=Nissan leaf#p960300
Each module weighs 8 lbs! Embossed on each is "500Wh", with 8 volts showing across the 2s2p main terminals. The endless-sphere site has a wealth of info. I did just check ebay, and there are currently none for sale. Weird indeed. There's a hybrid outfit in Vegas that sells them.

 

http://hybridautocenter.com/HAC4/index.php?option=com_content&view=article&id=72&Itemid=631

 

StoreDot electric car battery can be filled in 5 minutes. A company based in Tel Aviv wants to change that with the FlashBattery, which it claims can be filled in just five minutes.

The FlashBattery makes use of something called nanodots to deliver fast charging. Nanodots are chemically synthesized peptide molecules. They form the basis for a multi-function electrode, allowing super capacitor-style rapid charging with a slow discharge similar to a lithium-ion battery. The chemical compound isn't flammable and has a higher combustion temperature than graphite, which cuts the resistance of the battery.

StoreDot electric car battery can be filled in 5 minutes
StoreDot electric car battery can be filled in 5 minutes http://newatlas.com/storedot-flashbattery-quick-charging/49515/

 

The main problem with Li ion batteries, which are really a hybrid capacitor, is that they can be optimized for only a relatively narrow range of temperature. At low temperature the electrolyte for high temperature operation freezes. On the other hand, the low temperature electrolyte boils off at higher temperatures. The results they often advertise, only work in laboratory conditions. Some new research is looking into what they call "solid electrolyte". It is closer to the dielectric in a capacitor, but would allow the ions to migrate. Some of the nanomaterials, like carbon tubes and graphene, are not generating good results. In fact when I tested them, they were worse than any of the materials currently used in production batteries.

 

Hi Brian, Nice to see this thread revive again. I have my money on the development by the German organisation Frauenhofe. They are busy with up to 1000 Km battery for an electric car and also very fast recharging. Knowing the Germans, they will find a solution. The Nanodots is nothing else than a new marketing word for the technology already available. The trick lies in bringing the cost down for mass produced 1000 km range batteries.

 

What's the point, unless you have a sub station near your house. And what does the connector look like? 2500 amps @ 400V! That's about seven conductors the size of a quarter. Figure about $100 per running foot for the charging cable. A typical 2500A industrial switch weighs about 100 pounds and costs a couple thousand $.

 

Phil, you may have to do a re-calculation. Lets take a 80Kw engine and let us not be too stupid to run the battery totally flat. 80 Kw x 80 kw per hour driving x 11 hours = 880 Kwh charging in 5 minutes = 880 x 12 (60 minutes/ 5) = 10560 kw divided by 400 Volt gives you 26.4 Ampere. Big deal. I can do that with a normal 4 mm2 cable if needed. Sorry Phil, I still have my hopes on the Germans. 40 years ago I had a presentation to the South African government to make solar cells in the north of the country (excellent silicon sand), we had inexpensive electricity , grow the silicon and slice them. People needed work and make solar panels. We had aluminium in the ground and could make frames. We had thousands of km underground railway tracks and electric locomotives, thus traction knowledge was available so we also are making batteries. The suggestion was to make solar panels and small electric cars and have on every house solar panels. ( like Tesla is now offering) I was shot down by the automotive industry, their interest was at stake. No Phil, It is definitely coming and we will see in 2020 some lovely cars on the road. Bert

 

The problem this is creating will probably be worse than what it claims to fix. The toxic waste of Li Ion batteries is something no-one knows what to do with. The cost of dealing with it will be enormous.

 

10560kW = 10,560,000W, divide by 400V = 26,400A. I was using 90kWh as a capacity, not 880kWh

 

There is nothing stupid about running batteries completely flat. It is most efficient to have batteries sized to the power needs. Otherwise, is like people that overpower a vessel in the theory that it is better to run an engine at 30% load.

 

O.K. I made a bloop. Yes, that is indeed a serious problem to charge with those high currents. Maybe they have the idea to charge super capacitors and they charge into the battery. A super capacitor can handle that type of currents if placed parallel and charged over a period of time with lower currents. Phil, there are always solutions to problems and I see the progress of electric cars as a real reality and that type of problem is possible the least of them. Bert

 

That depends on what type of battery you run flat. A NiCad, A Metal H. Yes You can do that, but I would not try it with a Lithium battery, should the sensing for low voltage fail. Even a Lead Acid battery one should not run it flat, it will shorten the life time of the battery. Bert

 

Li Ion batteries are not damaged by using all the charge. That is what makes them attractive.

 

Hi Gonzo, That is interesting, in view that my LiFeP04 batteries are now 7 years old and I dare do not let them go down to below 2 Volt level per cell. I went into the Internet and got this thread from some fundi Tom.

"I have been running some tests on over discharged cells and the results are "interesting." The amount of damaged caused by over discharging is related to the amount of time the cell is in the discharged condition, and the quality of the cell.

Larry pointed out that premium cells often "recover," but there is some loss in capacity. The reason for the loss of capacity is that the electrolyte is corrosive and in an over discharged state, the electrolyte dissolves the copper electrode. Reducing the size of the electrode results in reduced capacity.

Yesterday I ran a test on an over discharged Li-Ion cell. The cell charged up normally, but after a full charge, it was only at just over 4 volts.

I discharged the cell at a 1C discharge rate, and the discharge curve was not uniform, but jumped around as if I had a loose connection within the cell.

The discharge capacity was less than half of the cells original capacity, so I know the cell suffered damage.

I did not want a damaged cell to cause any surprises, so I decided to totally discharge the cell down to 0.1 volts, then recycle it. The cell voltage quickly dropped, but then the cell heated up and the voltage rose back up. It got high enough to be useful in operating equipment. It then started another, somewhat normal, discharge curve and I got around another 25% of the cells capacity. The problem was that the cell temperature was rising during this discharge process. The cell temperature got up to 165 F, and the shrink wrap on the cell, shrunk.

I am not sure exactly what happened, but think it has to do with the dissolved copper trying to short out the cell. I was surprised that the cell seems to charge normally, then heated up during the discharge. I may have to monitor a charge on it to see if it is a smooth charge or if there are issues with charging as well.

Even though I can charge this cell up and use it to power a 2 amp load, the cell is not stable and should not be used.

I understand your curiosity, but keep in mind that the electrolyte that is used in Li-Ion cells is flammable, and that damaged cells are far more likely to have problems that cause cell heating.

I hope you understand that your battery pack is not OK, and should be replaced.

I do not recommend trying to recover over discharged Li-Ion cells. While it sometimes is possible, I feel that the risks far outweigh any benefits

Tom

This contradict your tests. Gonzo, don't think that I seek an argument, but I like to know, what do you do different, what makes a Li-Lion battery be able to drop to below 2 Volt ? Bert

 

Phil, What about this company on the Geneva show, a 1000 hp motorcar.

Why cant we have the same for boats. Read this on the review .

Artega introduces the 1,020-hp Scalo Superelletra, the next all-electric hypercar

Power is stored in a 120-kWh 800V lithium-ion battery pack, and Artega believes the 4,078-lb (1,850-kg) Superelletra will travel up to 311 miles (500 km, NEDC) per charge."With the Superelletra, we set out with a goal of delivering supercar performance with a range of at least 500 kilometers (311 mi) between charges. New high power and high efficient electric engines and high capacity batteries – with a new world record in terms of energy density – have been developed, giving us the technical edge that we needed for this breakthrough. You charge within just four minutes another 100 km (62 miles) of range. In 17 minutes, 80 percent of the capacity are charged."

OK OK, it is not yet in 5 minutes, but in 17 minutes 80% of recharging the 800Volt Lithium battery good for 400 km more.
Bert