It seems that the iPhone 17 Pro Max will be dethroning Apple's current battery life champ when it launches this September. According to a new leak, this year's model will match Samsung's own Galaxy S25 Ultra when it comes to battery capacity too, https://www.notebookcheck.net/Apple-iPhone-17-Pro-Max-battery-capacity-leaks-with-decent-gains-over-current-iPhone-16-Pro-Max.1050515.0.html
I presume Apple will invent Silicon Carbon batteries sometime around 2029 when they ship with the iPhone 20.