Yes, the Note 9 does have a supercapacitor inside (teardown)
We've seen a few Note 9 teardowns already, but when the grandmasters of all electronics' dissection speak, we ought to listen. The crafty folks from iFixit have gone through the trouble to take apart the new Galaxy Note 9, and it turned out that it was really a trouble, as with most of today's sealed waterproof flagships.
The Note 9 got a 4/10 score for repairability, as it needs a lot of heating, prying and suction cups to get open. The huge 4000 mAh battery is also glued in its own well, and, overall, replacing it is not for the faint of heart or those lacking the proper tools.
Apart from the intriguing heat dissipation piping, which is not full of liquid nitrogen, but nevertheless does the job of taking away warmth from the chipset, allowing higher GPU clock speeds and the like, the new star of the show is... a supercapacitor. Just as we envisioned when the Note 9 was announced, the S Pen does feature its own power source inside to maintain the Bluetooth connectivity when you press its button for action.
It's just that the power draw comes from a K8373 Seiko Instruments supercapacitor, which gets charged via a coil near the tip of the stylus. The phone's own wireless charging coil, the new finger scanner, the dual camera with variable aperture, and the breathtakingly compact system board can all be seen in the pictures below, reiterating once again this marvel of Samsung's engineering.