Tecno Unveils the World’s Slimmest Phone at MWC 2025, Featuring a Battery Bigger than the Galaxy S25 Ultra

Mobile World Congress (MWC) 2025 is about to begin next week, and there are some exciting product announcements expected even before the event kicks off. One of the highlights will come from Tecno, a brand that plans to introduce what they claim is the “world’s slimmest smartphone” in Barcelona. This phone is also said to have a larger battery than the Galaxy S25 Ultra, which is impressive.

Recently, there has been a lot of speculation about Apple potentially moving away from its Plus models. Instead, they might introduce a new lightweight phone called the iPhone 17 Air. Meanwhile, Samsung has beaten Apple to the launch of its own slim device, teasing the Galaxy S25 Edge during its Galaxy Unpacked event earlier this year, with a full launch expected in the months ahead.

In the world of slim smartphones, Tecno has jumped into the mix by teasing its new device named the Tecno Spark Slim. This phone measures just 5.75mm in thickness and features a sizeable 5,200mAh battery to complement its slim design.

Tecno recently shared a post on X, previously known as Twitter, which revealed the design and some main features of the Spark Slim. The phone will showcase a 6.78-inch 3D curved AMOLED display and include a 50MP dual-camera setup, making it not just thin but also equipped with great capabilities.

Though Tecno has not formally confirmed it, the high-capacity 5,200mAh battery in such a slim device hints that they might be using a new type of battery technology called silicon carbon. This innovation can store more energy and be more efficient compared to older lithium-ion batteries.

Silicon carbon batteries are becoming increasingly popular among smartphone manufacturers nowadays. Brands such as OnePlus, iQOO, and Poco are incorporating this technology into their devices, allowing them to fit batteries larger than 6,000mAh into phones without making them bulkier.

While Tecno’s Spark Slim is indeed very thin at 5.75mm, it may not hold onto the title of the world’s slimmest phone for long. There are rumors circulating that Apple’s upcoming iPhone 17 Air could be even slimmer, measuring just 5.5mm. So far, there hasn’t been any news suggesting a delay for this phone, and it’s expected to be revealed along with the iPhone 17 series during the typical launch event in September.

As the excitement builds ahead of MWC 2025, it will be interesting to see how these products perform and how the competition around slim smartphones continues to develop. Tecno’s Spark Slim is set to make a notable impression, but it appears that the race for the title of the slimmest smartphone is still very much alive. With top companies like Apple and Samsung stepping up with their own versions, consumers can look forward to some great options in the near future.