New Pack Architecture that is Likely Used in P100D and New TE Products

[JRP3]

The humor is in working this hard to defend a design decision you don't even know that Tesla's made.

Now you're changing the subject, so that cannot be the "humor" you "LOL'd" about in your post:

Also, here's the kicker: You guys think the end of the foil connects to the bottom of the cell. IT DOES NOT. There is an anode tab that takes the vertical end of the foil and electrically connects. The rest of the end of the internal cell is floating above the end cap.

LOL

Nothing about Tesla's patent or design decision.

The patent means nothing. Patents are filed for all sorts of ideas, the actual execution even if similar to the patent often has many details that were left out.

Of course that's quite possible. None of that changes the actual physics of heat transfer which we are discussing.

Simply put, you're obviously wrong, I think you actually realize it, hence your attempt to change the topic, instead of just admitting that you're wrong about the physics of heat transfer in a cell.

 

[scaesare]

The Solar PV industry moved from 600V strings to 1000V strings and so using storage battery systems just under the solar PV voltage string max makes sense in the area of trying to DC charge right of the main voltage bus of a PV array. Storage DC-attached to the PV array strings should have less charging losses versus DC-AC-DC conversion to charge-up the storage units. To go sustainable, we can't just keep seeing systems throwing away 15%+ of the energy produced.

I think 350KW may be his claim for the supercharger unit itself, not each car. Current limits through one SC that share A/B connected cars limits the aggregate throughput. IT would be a monumental change to allow for one car to charge at 350KW - however, if A+B itself could equal 350KW aggregate that is more than double today's throughput. Doubling current throughput should be enough to be groundbreaking alone. We don't need a single-car to charge at 350KW unles it is in "convenience store" speeds of 5 minutes to add 100 miles for price-A and 200 miles for price-A * 3. I would suggest that shorter term recharging at high rates be done at consumer pricing but also to increase price as time goes by. Going for a "full charge" should have a higher cost per kWh than going for a "quick-hit" opportunity charge. If you could get 80-100 miles in 5 minutes and move on, that would be gas-station/convenience store level speeds and consumer-level. And at these speeds, battery swap certainly would never be considered when travelling - as they were not really an issue with 120KW supercharging either, but would make long range trips slightly more pleasant if the charging times were shorter.

Yeah, it's obviously the stationary power products that have the driver for the high voltage packs at the moment.

It will indeed be interesting to see what the future holds for charge rates. While I agree that it's likely that the high-power DC chargers will always be shared (it makes sense due to charge tapering), it does appear that the ChargePoint is preparing to allow for 350KW charging to a single car.

Elon's subsequent tweet about 350kW chargers being "toys", along with JB's comments a while back that they think 10-minute charging is ultimately achievable leads me to believe that we will have to indeed see overall monumental change (even if spread out over time), if that's going to happen.

 

[AWDtsla]

Simply put, you're obviously wrong, I think you actually realize it, hence your attempt to change the topic, instead of just admitting that you're wrong about the physics of heat transfer in a cell.

I am not wrong and I did not change the subject. My view stands.

 

[bonaire]

Yeah, it's obviously the stationary power products that have the driver for the high voltage packs at the moment.

It will indeed be interesting to see what the future holds for charge rates. While I agree that it's likely that the high-power DC chargers will always be shared (it makes sense due to charge tapering), it does appear that the ChargePoint is preparing to allow for 350KW charging to a single car.

Elon's subsequent tweet about 350kW chargers being "toys", along with JB's comments a while back that they think 10-minute charging is ultimately achievable leads me to believe that we will have to indeed see overall monumental change (even if spread out over time), if that's going to happen.

10 minute charging was here 5 years ago with companies like A123 Systems and their LiFEPO4 batteries. In the RC world, 10C charging or 6 minutes - is commonplace for LiPoly blends. However, you may not want to have an unbalanced charging routine that can push even one cell into a "vent with flame" situation so it must be a careful move to such "consumerist" charge rates for their "wants" while they truly don't need that kind of speed, even for traveling. MS and MX drivers who do travel long distances have seen 120KW and probably felt it was adequate and some maybe seeing that double throughput might be desirable. With Autopilot now, many can text and work while on the highway rather than waiting for the next supercharger stopping point to pull out an iPad or laptop. Sure, in a perfect world - no charging would ever be necessary. Somewhere in between that and 2C charging is what is most likely to be our charging landscape in the EV world by 2020. 180KW per car would be a good A/B speed for 350KW SuperChargers by 2018. I suppose current cars might be able to take that kind of rate - but it could also be a call for Tesla to "get the fleet to upgrade again" and trade-in existing cars for the new high-speed charging variation. Most likely at the end of the big 2-year lease window from September - or roughly Q4 of 2018.

No car today can take 350KW - however, larger scale units like Buses and Trucks may already be doing that. Need to check with BYD and others who are using LTO cell chemistry for "stop and go VHA charging".

 

[jaguar36]

10 minute charging was here 5 years ago with companies like A123 Systems and their LiFEPO4 batteries. In the RC world, 10C charging or 6 minutes - is commonplace for LiPoly blends.

The energy density on those cells is significantly worse than the cells Tesla is using though. A battery that weighs 50% more would be a deal killer even if it charged much faster.

 

[scaesare]

10 minute charging was here 5 years ago with companies like A123 Systems and their LiFEPO4 batteries. In the RC world, 10C charging or 6 minutes - is commonplace for LiPoly blends. However, you may not want to have an unbalanced charging routine that can push even one cell into a "vent with flame" situation so it must be a careful move to such "consumerist" charge rates for their "wants" while they truly don't need that kind of speed, even for traveling. MS and MX drivers who do travel long distances have seen 120KW and probably felt it was adequate and some maybe seeing that double throughput might be desirable. With Autopilot now, many can text and work while on the highway rather than waiting for the next supercharger stopping point to pull out an iPad or laptop. Sure, in a perfect world - no charging would ever be necessary. Somewhere in between that and 2C charging is what is most likely to be our charging landscape in the EV world by 2020. 180KW per car would be a good A/B speed for 350KW SuperChargers by 2018. I suppose current cars might be able to take that kind of rate - but it could also be a call for Tesla to "get the fleet to upgrade again" and trade-in existing cars for the new high-speed charging variation. Most likely at the end of the big 2-year lease window from September - or roughly Q4 of 2018.

No car today can take 350KW - however, larger scale units like Buses and Trucks may already be doing that. Need to check with BYD and others who are using LTO cell chemistry for "stop and go VHA charging".

I don't think JB was speaking in a vacuum.. the assumption is likely that they are targeting those charge rates with chemistries that still perform well along he other axes needed for their EV usage: energy density, cycle life, etc...

Some the chemistries that support those high C rates also have 10X less cycle life than Tesla's NCA cells...

 

[bonaire]

The energy density on those cells is significantly worse than the cells Tesla is using though. A battery that weighs 50% more would be a deal killer even if it charged much faster.

LiPoly - or "LiPo" in the RC world is similar in weight, if not lighter, than can cells. Yes, A123 is heavier and belongs in buses and other big form factor or possibly stationary. Since LiFEPO4 has seen 8000+ 1C cycles, it could do 15-20 years as stationary and have 75-80% capacity remaining. LTO is also showing nearly 20,000 cycles (per their vendors) and good for Buses and Stationary - however, more costly now.

 

[jaguar36]

LiPoly - or "LiPo" in the RC world is similar in weight, if not lighter, than can cells. Yes, A123 is heavier and belongs in buses and other big form factor or possibly stationary. Since LiFEPO4 has seen 8000+ 1C cycles, it could do 15-20 years as stationary and have 75-80% capacity remaining. LTO is also showing nearly 20,000 cycles (per their vendors) and good for Buses and Stationary - however, more costly now.

The best hobby type lipos with a 5C or greater rate that I've been able to find are these. Which are 6.8g/Wh. Tesla cells (at least in the 90) are only 4g/Wh. If you get into some of the cells with even higher charge rates, like the graphene ones from hobbyking, they are even heavier, like 18g/Wh.

 

[bonaire]

I get 4.2 g/Wh for a 18650B cell (3.6V and 3200mAh and 47.5g). Anyway - right, remove all packaging and go with raw cells to do a true compare. These RC cells have plastic wrap, usually thick copper wires and the connection plug included in the full pack weight. I think they also contain some extra amount of electrolyte in the RC packs. The Tesla cells would be raw cylinders, no paint or plastic wrap; as naked as possible to keep the weight down. Then, no lead wires other than the wire/fuse that connects the end caps to the bus within the module. It's an efficient setup and going 2170 makes it better for capacity per kg and per volume. Other automakers are starting to look at this as a good option for larger packs. Using prismatic-wrapped or stacked-flat cells from LG Chem could be useful but not as good for larger capacity systems or smaller cars. The real future may lie in other chemistry choices including Li-S if they can get cycle count above 1000.

Kokam's NMC at the bottom of this Lithium Ion Polymer Cells - High Energy High PowerㅣKokam Battery Cells has a higher energy density than current 18650B but they are much larger (ie buses, trucks, storage). I am more interested to see what the LTO cells can do with their 20,000 1C cycles with 80% capacity at end. Great for lower-performance needs such as storage, buses, commuter cars and eBikes used for commuting daily.

 

[Jeff N]

Also consider that GM is using a similar cooling scheme in the Bolt, (i.e. cooling through the bottom of the cells instead of the sides), even though they are using prismatic cells,. Much greater cooling area available through the sides with prismatic, since the flat sides allow full contact on both sides of the cells, yet they went with bottom cooling.

The Bolt EV pack has a thin aluminum passive heat fin in full contact with the side of each cell and that fin is then connected at the base to a cooling plate. Thermal energy is conducted through the fin rather than through the bottom of the cell itself.

 

[JRP3]

The Bolt EV pack has a thin aluminum passive heat fin in full contact with the side of each cell and that fin is then connected at the base to a cooling plate. Thermal energy is conducted through the fin rather than through the bottom of the cell itself.

Interesting, I wasn't aware of that.

 

[bonaire]

Volt, Bolt and probably others using liquid cooling TMS in their packs use these space-consuming fins. The nice thing I find with the cylinders is that you can cool them both through the bottom plate cooling system and if necessary, modest air-flow through gaps within the cells. They won't get hot unless using supercharging (ie - fast charge acceptance) or heavy draw via acceleration (ie. a Nürburgring lap or afternoon laps at Laguna Seca). Space is less critical in larger vehicles - but making smaller cars as BEVs will require tight battery placement.

 

[stopcrazypp]

LiPoly - or "LiPo" in the RC world is similar in weight, if not lighter, than can cells. Yes, A123 is heavier and belongs in buses and other big form factor or possibly stationary. Since LiFEPO4 has seen 8000+ 1C cycles, it could do 15-20 years as stationary and have 75-80% capacity remaining. LTO is also showing nearly 20,000 cycles (per their vendors) and good for Buses and Stationary - however, more costly now.

Are you sure about that? BYD uses LiPo and their e6 has horrible energy density in terms of weight.

 

[Jeff N]

Are you sure about that? BYD uses LiPo and their e6 has horrible energy density in terms of weight.

You just triggered one of my pet-peeves.... You may already know this but I'll rant a bit since I think many people are confused about "LiPo".

The terminology is often used confusingly as if it implies a particular type of battery anode/cathode chemistry or internal construction design which can in turn strongly effect energy or power density. Instead, LiPo just means a cell of any Lithium-based chemistry and internal construction which just happens to be packaged in pouch format perhaps with the electrolyte stabilized into a gel by polymerizing it (adding plastic).

As Wikipedia says:

Lithium polymer battery - Wikipedia

A lithium polymer battery, or more correctly lithium-ion polymer battery (abbreviated variously as LiPo, LIP, Li-poly and others), is a rechargeable battery of lithium-ion technology in a pouch format. Unlike cylindrical and prismatic cells, LiPos come in a soft package or pouch, which makes them lighter but also less rigid.

The designation "lithium polymer" has caused confusion among battery users because it can be interpreted in two ways. Originally, "lithium polymer" represented a developing technology using a polymer electrolyte instead of the more common liquid electrolyte. The result is a "plastic" cell, which theoretically could be thin, flexible, and manufactured in different shapes, without risk of electrolyte leakage. The technology has not been fully developed and commercialized[1][2] and research is ongoing.[3][4][5]

The second meaning appeared after some manufacturers applied the "polymer" designation to lithium-ion cells contained in a non-rigid pouch format. This is currently the most popular use, in which "polymer" refers more to a "polymer casing" (that is, the soft, external container) rather than a "polymer electrolyte". While the design is usually flat, and lightweight, it is not truly a polymer cell, since the electrolyte is still in liquid form, although it may be "plasticized" or "gelled" through a polymer additive.[6] These cells are sometimes designated as "LiPo"; however, from a technological point of view, they are the same as the ones marketed simply as "Li-ion", since the underlying electrochemistry is the same.[6]

So, the more pertinent fact is the cathode and anode chemistry. BYD, like most other Chinese firms, uses Lithium Iron Phosphate cathodes in the e6 which are less energy dense and heavier. Most non-Chinese car makers are using a variant of Lithium Nickel Manganese Cobalt cathodes although Tesla uses Lithium Nickel Cobalt Aluminum. Almost everyone uses some form of graphite anode although Tesla/Panasonic now sprinkle some silicon into the mix for better energy density.

 

[stopcrazypp]

You just triggered one of my pet-peeves.... You may already know this but I'll rant a bit since I think many people are confused about "LiPo".

The terminology is often used confusingly as if it implies a particular type of battery anode/cathode chemistry or internal construction design which can in turn strongly effect energy or power density. Instead, LiPo just means a cell of any Lithium-based chemistry and internal construction which just happens to be packaged in pouch format perhaps with the electrolyte stabilized into a gel by polymerizing it (adding plastic).

As Wikipedia says:

Lithium polymer battery - Wikipedia


So, the more pertinent fact is the cathode and anode chemistry. BYD, like most other Chinese firms, uses Lithium Iron Phosphate cathodes in the e6 which are less energy dense and heavier. Most non-Chinese car makers are using a variant of Lithium Nickel Manganese Cobalt cathodes although Tesla uses Lithium Nickel Cobalt Aluminum. Almost everyone uses some form of graphite anode although Tesla/Panasonic now sprinkle some silicon into the mix for better energy density.

Yes, I'm aware of that, but when people say LiPo they usually mean LFP (LiFePo4) in a LiPo format and that is the context I am using it on. LiPo is typically not safe enough to use with cobalt based chemistries for auto applications. Sorry, just being lazy.

 

[scaesare]

While there is lab research in to polymer "plasticized" batteries, it appears that cells available on the market today billed as "LiPo" or "Li-Poly" are speaking primarily as a pouch format cell using a gelled electrolyte:

The second meaning appeared after some manufacturers applied the "polymer" designation to lithium-ion cells contained in a non-rigid pouch format. This is currently the most popular use, in which "polymer" refers more to a "polymer casing" (that is, the soft, external container) rather than a "polymer electrolyte". While the design is usually flat, and lightweight, it is not truly a polymer cell, since the electrolyte is still in liquid form, although it may be "plasticized" or "gelled" through a polymer additive.[6] These cells are sometimes designated as "LiPo"; however, from a technological point of view, they are the same as the ones marketed simply as "Li-ion", since the underlying electrochemistry is the same.[6]

Further discussion that they aren't really a unique chemistry, but based on existing chemistries:

Li-polymer can be built on many systems, the likes of Li-cobalt, NMC, Li-phosphate and Li-manganese, and is not considered a unique battery chemistry. The majority of Li-polymer packs are cobalt based; other active material may also be added.
...
Charge and discharge characteristics of Li-polymer are identical to other Li-ion systems

Thus you it would seem you can't really lump all Li-Poly together, but rather you'd need to compare specific chemistries.

For example, here are some comparisons of several different Li-ion chemistries:

Comparison of Types of Li-ion Cells

It demonstrates that power density, energy density, cost, cycle life, thermal stability, etc... are require a careful balance for a specific usage...

 

[scaesare]

Hehe... Jeff beat me while I was composing...

 

[Jeff N]

LiPo is typically not safe enough to use with cobalt based chemistries for auto applications. Sorry, just being lazy.

Colbalt-based? All of GM's recent plugin cars use LiPo cells and they use some Cobalt. I think "NMC" chemistries are often as much Cobalt-based as they are Nickel or Manganese yet it is considered among the safer chemistries which is why many automakers use variants of it instead of NCA which is consider inherently somewhat "less safe" but safer than the Lithium Cobalt-only cathodes used in the cells in the Roadster pack.

 

[JRP3]

Yes, I'm aware of that, but when people say LiPo they usually mean LFP (LiFePo4) in a LiPo format and that is the context I am using it on. LiPo is typically not safe enough to use with cobalt based chemistries for auto applications. Sorry, just being lazy.

It seems to me that most people using "LiPo" terminology are referring to lithium polymer gelled electrolyte, and ususlly cobalt based chemistries:

To make the modern Li-polymer battery conductive at room temperature, gelled electrolyte has been added. Most Li-ion polymer cells today incorporate a micro porous separator with some moisture. Li-polymer can be built on many systems, the likes of Li-cobalt, NMC, Li-phosphate and Li-manganese, and is not considered a unique battery chemistry. The majority of Li-polymer packs are cobalt based; other active material may also be added.

 

[3Victoria]

You'd be ignoring the fact that Tesla stated the early production would be higher end models with better profit margins, just as with their previous vehicles.

Also, I am not convinced we won't see the base model with a bigger pack (60?) if that's what required to beat the Bolt in range.