The author is misinterpreting physical space limit with battery chemistry limit. Yes, it's quite obvious that you can only fit so many 18650 cells in the same pack space. That's as obvious as saying you can only fit at most 10 gallons of gasoline in a 10 gallon tank, ergo the gas tank has reached its limit. It's Business Insider, so they can be forgiven for creating logic that creates clicks and circulates in the echo chamber of the uninformed.

By definition, a thing's capability is it's limit, until the next incremental change or evolution of the thing comes along, then that's the next limit, and so it goes. The current Intel processor is at its limit, by definition, until the next Intel processor comes along.

The 18650 cell is a form factor, not a type of chemistry. It has gone through a few changes in chemistry. The chemistry of the cells on the new 90 kWh pack is different from cells on the legacy 85 kWh pack. The latest pack, the 100 kWh, is the result of physical space optimization, cooling optimization, and a BMS update. It may very well be the limit of what can be physically stuffed and controlled in the pack, but that's not the same as saying Tesla batteries have reached their limit, the article's implication. Tesla plays with chemistry, space volume, cooling, and BMS. Pick a combination of each for the next battery pack. As new discoveries are proven, they are implemented. We don't know Tesla's R&D pipeline, but you can bet there's a new form factor and there a probably a dozen candidate recipes for new chemistries that will go into the new form factor. No one knows where the next limit will be but it's guaranteed to be a step up from current levels. That's an obvious statement and dispels notions of having reached a limit.