Perhaps override the heat management clock frequency limiters and run every CPU, GPU, neural and video core at maximum frequency on the most energy burning instructions, with constant cache misses forcing continuous refreshes, and writes to memory, while locking the camera flash LED on, maximum solid white screen brightness, until the rising heat damages something?
Starting with a full battery?
Not sure if this is possible, or if enough heat could be produced for a long enough time to ignite a battery fire, but that would be my approach.
Or just keep writing to the flash storage until you break down the oxide layer within the floating gate transistors. The phone won’t “destruct” but it would become inoperable.
