Google And Apple Won't Use Silicon-Carbon Batteries For One Reason

Silicon-carbon (Si-C) batteries are the next step forward in an industry that's largely been stagnant for the past 30 years. Traditional lithium-based batteries do the job well enough, but as the newest smartphones strive to outperform each other in every metric — including battery life — the limits of graphite-based batteries are being reached. By opting for silicon-carbon batteries, phones like the RealMe P4 Power can reach upwards of 10,000mAh in battery capacity, almost double that of the most expensive phones with lithium-ion (Li-ion) batteries.

What makes this possible are certain properties that silicon holds. First, silicon can simply store a lot more energy than graphite, with theoretical estimates putting it almost 10x as efficient as graphite, the material used in lithium-ion batteries. This lets manufacturers fit better batteries in thinner form factors, yes, but it also lets them put absurdly large batteries in normal phone sizes.

With the technology becoming more common in phones released last year, with many of Vivo, OnePlus, and Xiaomi's flagships having silicon-carbon batteries, it didn't take much thinking to expect the latest iPhone and Pixel models to boast the same impressive battery capacities. Yet, the iPhone 17 and Google Pixel 10 are both out, and these batteries are nowhere to be seen. So why are these companies intentionally staying away from a technology that would let their phones last multiple days on a single charge?

As YouTuber Marques Brownlee explained, silicon expands significantly more than the graphite used in traditional batteries. The expansion itself isn't unusual; whenever you charge your phone, your battery grows, and whenever it discharges, it shrinks in size. For Li-ion batteries, this expansion is just around 10% of the battery's size. For silicon-carbon ones, this turns into a huge 300% increase in volume. If your battery is constantly expanding and contracting in size, it'll eventually lead to issues such as the battery swelling up. In worst-case scenarios, the battery can even burn up or explode, although it's rare.

To ensure these issues don't happen, the companies pushing these batteries don't use pure silicon; they mix it with a material that can counteract the expansion to an extent. That's where the carbon comes in, making the batteries more stable and ensuring they don't run into issues too soon.

The more carbon is used alongside the silicon, the more stable the battery becomes. Unfortunately, the more stable the battery becomes, the less energy-dense it'll be. Phones with flexing batteries, like the aforementioned RealMe Power P4, can have these batteries by using exceedingly smaller amounts of carbon, opting for more battery power in exchange for a potentially more unstable battery.

This doesn't mean that your new OnePlus is sure to give out early or explode in your hand, though; the technology is rapidly evolving, and any phone available to the public has to pass through rigorous safety testing. Even if Apple, Samsung, and Google haven't made the jump yet, they might just be waiting for more development in these batteries. Plus, it's not like Apple needs the extra battery, as the latest iPhones can already outlast phones with batteries twice in capacity.