How silicon-carbon battery tech could power Apple’s super-thin iPhone 17 Air

iPhone 17 Air battery technology: Making a thin phone usually means sacrificing battery life by using a smaller, less powerful battery, but thanks to new silicon-carbon battery technology, that might be about to change.

This technology isn’t brand new, it’s been in the works for decades and is already being used in some products, as per a report. For example, Whoop fitness trackers have had silicon-carbon batteries since 2021, as per Wired. Phone brands like Xiaomi, Honor, OnePlus (in the OnePlus 13), and Nothing (in its Phone 3) have recently adopted it too, as reported by Wired. So far, folding phones have taken advantage of this tech to get thinner, while traditional candy bar phones have used it to pack in bigger batteries without getting bulkier, according to the report.

iPhone 17 Air May Use Silicon-Carbon Battery

Apple is expected to reveal the iPhone 17 Air on September 9, rumored to be just 5.5 millimeters thick, making it the slimmest iPhone yet, and there are speculations that Apple might be using a silicon-carbon battery to keep battery life close to what users expect despite the phone’s thinness, as reported by Wired.


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How Thin Are Today’s Smartphones

Most smartphones today are around 8 to 9 millimeters thick, as per the report. For example, the Samsung Galaxy S25 Ultra is 8.2 mm, the iPhone 16 Pro Max is 8.25 mm, and the Google Pixel 10 Pro XL is 8.5 mm, as per the Wired report. But 2025 has seen a wave of ultra-thin phones. Samsung’s Galaxy S25 Edge measures just 5.8 mm, the Galaxy Z Fold7 is 4.2 mm when unfolded, and Huawei’s Mate XT Ultimate is 3.6 mm unfolded, as per the Wired report.

Which Phone Brands Are Using Silicon-Carbon Battery Technology

While some brands like Huawei and Honor have embraced silicon-carbon batteries for these thin designs, Samsung is sticking with traditional lithium-ion batteries and instead focusing on making their displays more energy-efficient, as per the report. Still, the battery life on Samsung's thinner phones hasn’t impressed many users, as per the report.

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What Makes Silicon-Carbon Batteries Different From Lithium-Ion Batteries

The silicon-carbon battery, which is expected to be used in the new iPhone 17 Air is still a lithium-ion battery, but instead of using graphite in the anode (the battery’s negative side), it uses a mix of silicon and carbon, as per the Wired report.

Silicon can hold about 10 times more lithium ions by weight compared to graphite, which means it can store more energy in the same space, as per the report. Because the anode takes up a big chunk of space in a battery, around 60%, using silicon lets manufacturers either increase battery capacity or shrink battery size while keeping energy the same, as per the Wired report.

The silicon-carbon anode material is made by companies like Group14 Technologies and then supplied to battery makers like ATL, who manufacture the final batteries used in phones and laptops, as per the report. This swap is seamless for manufacturers since they can replace graphite powder with the silicon-carbon blend without changing their production process, as per the Wired report.

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How Will Apple Use Silicon-Carbon Batteries in iPhone 17 Air

Phone makers have two choices: to keep the same phone thickness but boost battery size (like OnePlus with their 6,000 mAh battery in the OnePlus 13) or make the phone thinner while maintaining a battery capacity that still meets user expectations, as per the report.

Apple seems to be taking the second route, as there are speculations that the iPhone 17 Air’s battery will be around 2,900 mAh, smaller than previous models, given its 6.6-inch screen size, as reported by Wired. However, Apple is reportedly using new power-saving technology, including a more efficient C1 modem, to help the battery last as long as other iPhones, according to the report.

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FAQs

Will the iPhone 17 Air have a silicon-carbon battery?
It’s rumored to, which could explain how Apple is making it so thin while still maintaining good battery life.

How does Apple plan to keep battery life up with a smaller battery?
Apple is using power-saving tech like a more efficient C1 modem to help extend battery life despite the smaller size.