Solderless is the holy grail because long term it enables total reuse of old cells. After 8 years a saggy pack with high internal resistance and only 70% of initial capacity might be no good to you on your mobile EV, but I will buy them by the ton to use in huge stationary energy storage packs where they can go on to last another 20 years (given it is a stable chemistry such as NCA).
Even current Tesla packs are totally useless for use at the cell level because they are all glued in place. Ever seen the one the video where the drop a Telsa pack 20 feet from a fork lift and still can't pry the 18650's loose?
At the module level, YES, you can reuse Tesla batteries in some respect, but it does not allow any real flexibility, and no real secondary use ecosystem for reuse of batteries will ever come to be as it does not make financial sense. I would much rather be able for a robot to tear down the pack, resort and rematch the gold cells after tossing the duds, and then rebuild it into compact stationary pack. I don't care if it is the size of a fridge using outdated 8 year old tech. It will power solar homes for pennies on the dollar.
If we standardize on the cell format and go solderless then ANY module can simply be torn down and rebuilt. If all manufacturers moved in this direction they could build battery packs into any form factor they like and still have a second life. No one has figured out large scale second life use of lithium batteries yet. Does your stationary battery system only use Leaf modules, or Tesla modules, or GM modules, or air cooling, or liquid cooling, or whatever?
Right now that form factor is 18650. In a few years the new standard will be the gigafactory cell format.
Also note when you tear apart a 8 year old pack usually only a few cells are bad (outliers) because they have extremely tiny defects. If a cell hasn't developed high self discharge after 8 years it means it has basically ZERO manufacturing defects. These cells are like gold even though they have lost capacity and have higher resistance due to plating. It's like someone has stress tested your cells for you for 8 years to sort out the duds. Thanks dude! When you rebuild a pack using these gold cells you will never have to service it again.
It also allows the service of new modules. You could have a brand new module with 100 cells in parallel. If enough cells go bad that the module require replacement (let's say 7), current practice is to just replace it and toss the old one. You could have 93 Rank A almost brand new cells going to the recycler. This is insane.
Here again is where small format cells make sense besides the safety factor. If those 100 cells were made as one big large format cell, now any internal defect would require all "100 cells" be junked. With 100 cells in parallel if you lose one cell you only lose a small percentage of total pack capacity. If you had a large EV with no cells in parallel (all very large format), any time a single large format cell developed a problem, the whole pack would have to be rebuilt or junked. During a pack rebuild a pack with small format cells will always have a larger percent of salvageable watt-hours of energy storage than a large format pack, hence the green option.
Even current Tesla packs are totally useless for use at the cell level because they are all glued in place. Ever seen the one the video where the drop a Telsa pack 20 feet from a fork lift and still can't pry the 18650's loose?
At the module level, YES, you can reuse Tesla batteries in some respect, but it does not allow any real flexibility, and no real secondary use ecosystem for reuse of batteries will ever come to be as it does not make financial sense. I would much rather be able for a robot to tear down the pack, resort and rematch the gold cells after tossing the duds, and then rebuild it into compact stationary pack. I don't care if it is the size of a fridge using outdated 8 year old tech. It will power solar homes for pennies on the dollar.
If we standardize on the cell format and go solderless then ANY module can simply be torn down and rebuilt. If all manufacturers moved in this direction they could build battery packs into any form factor they like and still have a second life. No one has figured out large scale second life use of lithium batteries yet. Does your stationary battery system only use Leaf modules, or Tesla modules, or GM modules, or air cooling, or liquid cooling, or whatever?
Right now that form factor is 18650. In a few years the new standard will be the gigafactory cell format.
Also note when you tear apart a 8 year old pack usually only a few cells are bad (outliers) because they have extremely tiny defects. If a cell hasn't developed high self discharge after 8 years it means it has basically ZERO manufacturing defects. These cells are like gold even though they have lost capacity and have higher resistance due to plating. It's like someone has stress tested your cells for you for 8 years to sort out the duds. Thanks dude! When you rebuild a pack using these gold cells you will never have to service it again.
It also allows the service of new modules. You could have a brand new module with 100 cells in parallel. If enough cells go bad that the module require replacement (let's say 7), current practice is to just replace it and toss the old one. You could have 93 Rank A almost brand new cells going to the recycler. This is insane.
Here again is where small format cells make sense besides the safety factor. If those 100 cells were made as one big large format cell, now any internal defect would require all "100 cells" be junked. With 100 cells in parallel if you lose one cell you only lose a small percentage of total pack capacity. If you had a large EV with no cells in parallel (all very large format), any time a single large format cell developed a problem, the whole pack would have to be rebuilt or junked. During a pack rebuild a pack with small format cells will always have a larger percent of salvageable watt-hours of energy storage than a large format pack, hence the green option.
