Um lol no. It would have to be 3x the physical size of the original battery to have 3x the capacity. But if they made a new, thicker phone case to accommodate it, that could work and such things have been done a few times for other phones.
https://9to5mac.com/2023/11/21/iphone-battery-mah-capacity-list/
iPhone 7 Plus battery mAh capacity?
2900 mAh – 11.10 watt-hour
Generally-speaking, you can’t improve a whole lot on capacity from a manufacturer’s battery in the same space.
You definitely can’t more-than-triple capacity.
On the other hand, there are a lot of sketchy people selling batteries with incorrect capacity claims out there.
I am all for large batteries, but doing so requires device manufacturers doing larger cases with space for larger batteries, not just dropping a replacement battery into the same space.
Follow-up to OP: If you do want that kind of large battery in a smartphone, you can get it. There are a few Chinese vendors that make “ruggedized” smartphones. For whatever reason, maybe because people want to be able to operate away from power, this class of device tends to have both a tough shell and large batteries; it was one of the few places I could find phones that had really huge batteries.
Doogee is one such manufacturer: here’s one with a 10800 mAh battery – I really wish that we’d use Wh ratings rather than mAh, but whatever – and another from the same manufacturer with a 22,000 mAh battery. These are also quite large.
For the former phone:
395 g
Or 0.87 lbs.
For the latter phone:
The weight is 543g or nearly 1.2 lbs
But that gives some idea of the kind of the size tradeoff that you might need.
Of course, it is not original and I would not trust a component as critical as the battery in any brand other than the original from the manufacturer for safety reasons.
Especially since some South Korean smartphone brand illustrated how it is a bad idea to have a bad quality battery in a smartphone.
Spoiler: It gets hot. Very hot.
Y’know, if something seems too good to be true, it pretty much always is. Batteries are no exception.
