The iPhone 15 is a hot product, and not always in a good way: early models had a tendency to overheat, and while that's been fixed in iOS updates it seems that Apple's dismissal of any design issues – Apple said that the iPhone 15's titanium frame was better at heat dissipation than older stainless steel designs – may not mean that thermal issues aren't still a concern. A new report says that Apple is considering a fairly significant redesign to address thermal issues.
The report comes from tipster Kosutami, who previously revealed the existence of a HomePod with a built-in screen before any prototypes had leaked. This time the news is that Apple is "actively working on a graphene thermal system of iPhone 16 Series to solve the heating problem". And as part of that redesign the iPhone 16 Pro and Pro Max will have their batteries encased in metal shells for better thermal isolation.
The heat (sink) is on
Current iPhones have a copper heat sink. Graphene is a better conductor of heat, so it's a good candidate for any thermal redesign. And this wouldn't be the first time Apple has rethought its heat management: in the Apple Watch Series 7, Apple changed its batteries' black foil casing to metal ones. So the rumoured iPhone change isn't far-fetched – although so far it is uncorroborated, so we'd recommend the traditional pinch of salt until there are more details to support the tipster's claims.
The interesting question here, for me at least, is why: is the change happening to address an existing issue, or is it to improve things for future, faster processors? I suspect it's the latter, because the initial flurry of iPhone overheating reports went very quiet after Apple's iOS updates set out to solve the problems – so it does seem that those problems were caused somewhere in the software rather than the hardware.
However, thermal management is an ongoing issue in all kinds of devices from smartwatches and phones to full-blown computers, so it would be more of a surprise if Apple weren't testing out alternative options across all of its devices, iPhone included.