Room for improvement in packing cells closer? Or room for improvement in cell density (which is happening naturally even without Tesla, for example the NCR18650B offers 3400mAh now)? Maybe both?
There's a discussion in EVTV about the need for expansion room for pouch cells, but it seems it was not conclusive (Jack does say A123 doesn't expand unlike other pouch cells and that the issue of flexing is a bigger concern). I take your word and Jack's that there is no need for room for expansion, but obviously the cooling plates take up space.
Yes both. I'm expecting at some point higher density cells, but cells with better temperature tolerance, improved electrolytes, should allow tighter packing with little to no active cooling. I'm not aware of anyone cooling the LiFePO4 cells we use in our conversions, even in warmer places such as Nevada, with no signs of capacity loss after 3+ years. If cooling is less of a concern and cell level safety is better, and production volume of pouch cells increases enough to get a price per kWh near that of 18650 production, then we don't need to have all that empty space and cooling channels. For now they are a necessary evil, but I don't expect that to always be the case.
I think one of the ideas is that if you run a Model S for 150k miles or whatever and essentially kill the battery pack, at that point you can swap in a new one and have a car which is a lot closer to Good As New than any ICE would be.
Other chemistries are less sensitive to the cold, as well as heat, and there are other ways to heat a pack. I do expect that design to remain for a while but I also expect to see it eliminated at some point.
The car could have burnt if no cells at all had burned. A high current short can set fire to other vehicle components, as probably happened in this case. Probably the plastic battery cover was the first thing to ignite from the heat.
Exactly.
If the connections had been properly tightened the design probably would have been fine and no fire would have ever occurred.
