The iPhone 17 Air Could Use a Silicon-Carbon Battery. What Is It? – Apple has taken the second approach with constraints. Rumors claim the iPhone 17 Air’s battery capacity will lie around 2,900 mAh, a sharp drop from recent iPhone models, especially at the 6.6-inch screen size. But the corporation is purportedly making up for it with power-saving measures to make sure battery life remains equivalent to other iPhones, including Apple’s more efficient C1 modem that debuted in the iPhone 16e earlier this year. Luebbe declined to comment on whether Group14’s silicon-carbon composite is being used in the iPhone 17 Air’s batteries; Sila Nanotechnologies and Enovix did not immediately respond to a request for comment.
What’s the Catch?
The difficulty with silicon batteries is that they expand. When you lithiate raw silicon, Luebbe claims it can swell up to three times its initial volume. Lithium-ion batteries also swell; you’ve probably heard of or maybe even experienced this, as it can happen for a plethora of reasons. It signifies something has gone wrong, and the battery is now a safety risk. The iPhone 17 Air Could Use a Silicon-Carbon Battery. What Is It?
It’s this difficulty that researchers and industry have spent decades attempting to address, and the solution lies in the carbon portion of the term. It starts to get a bit complicated here—and each silicon anode firm has its own proprietary process—but Luebbe says Group14’s method is to start with a porous carbon material.
“Imagine a carbon sponge, but the pores of that sponge are on the single-digit molecule wide, we’re talking less than 10 nanometers wide,” he explains. These pores are filled with silane gas (the silicon), but only about halfway. The particle you’re left with is made up of silicon, carbon, and void space. When the lithium ions travel over from the cathode to the anode and the silicon lithiates, it expands to cover the vacant spaces of the particle.
“It mitigates the expansion at the particle level, so the battery doesn’t see the expansion, so it stabilizes the battery, and you get excellent cycle life,” Luebbe explains. “That’s the critical insight in the invention: really learning how to internalize that expansion, so that it’s insulated from the battery chemistry and mechanical operations.”
Vincent Chevrier has been a researcher in the silicon industry for 15 years and is a partner at battery consultancy firm Cyclikal. He says while silicon is here to stay as a material to be utilized in lithium-ion batteries, there are still a few barriers for broader use, especially cost. The iPhone 17 Air Could Use a Silicon-Carbon Battery. What Is It?
Companies like Group14 employ silane gas instead of solid silicon, which offers greater battery performance, but might be 10 times the cost. That might make it difficult to sell their composite to battery makers, and it could drive up the pricing of consumer products. The iPhone 17 Air is reported to cost around $1,099, a potential $200 jump from the iPhone 16 Plus it’s anticipated to replace, though there could be other variables affecting its pricing, such tariffs.
Chevrier also says he often sees silicon-carbon companies overstate the energy density promises.
Group14, for example, states on its website that its silicon batteries can give up to 50 percent more energy density than standard lithium-ion batteries. But if the material is merely dumped in to replace graphite and not much else is altered with the battery, you’re more likely going to see a 10 percent gain in energy density with a transition to a silicon-carbon anode. Redesign the battery cell, and then it’d be able to witness an increase of up to 30 percent. The iPhone 17 Air Could Use a Silicon-Carbon Battery. What Is It?
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