Mobile World Congress (MWC) 2025 kicks off next week, and even before the mega-event begins, we have some potential product announcements to look forward to. The first is from Tecno, which is set to unveil the ‘world’s slimmest’ smartphone in Barcelona, with a battery that’s bigger than the Galaxy S25 Ultra’s.
There has been a lot of talk in recent months about Apple ditching its Plus range in favour of a slim phone called the iPhone 17 Air. Samsung beat its American rival to the punch by teasing its own slim phone, the Galaxy S25 Edge, at its Galaxy Unpacked event earlier this year, and is set to launch it in the coming months.
World’s slimmest phone teased:
With all the buzz around slim phones, Tecno took the opportunity to tease its own thin and light device called the Tecno Spark Slim, which is just 5.75mm thick and has a 5,200mAh battery.
In a post on X (formerly Twitter), Tecno unveiled the design of the Spark Slim and also revealed some key details about the smartphone. The Spark Slim will feature a 6.78-inch 3D curved AMOLED display and will be paired with a 50MP dual camera setup.
While Tecno hasn’t officially confirmed it, the presence of a 5,200mAh battery in such a thin form factor suggests that the Transsion-owned company is using a silicon carbon battery – a type of technology that can store more energy and improve efficiency compared to traditional lithium ion batteries.
Silicon carbon technology has become very common in the smartphone market these days, with companies such as OnePlus, iQOO and Poco using it to increase the size of their phone’s batteries to over 6,000mAh while retaining the same form factor.
Will Tecno Spark Slim remain the world’s slimmest phone?
While Tecno’s claimed thickness of 5.75mm for the Spark Slim is much thinner than some of the traditional phones, the brand may not be able to hold on to the world’s slimmest phone crown for long.
If leaks are to be believed, Apple’s iPhone 17 Air could come with a thickness of just 5.5mm. There has been no news of the phone being delayed, suggesting that it could be unveiled alongside the iPhone 17 series at the usual September launch event.
