Tecno Spark Slim: A Leap in Ultra-Thin Design with a Surprising Battery Life

Tecno is showcasing the Spark Slim at MWC 2025, positioning it as a potential candidate for the 'world’s thinnest phone.' The device boasts an impressive 5.75mm profile, making it over 33% thinner than the Galaxy S25 Ultra and nearly 2mm thinner than the iPhone 16. Despite its slim design, the Spark Slim packs a 5,200 mAh battery, which is 200 mAh larger than the Galaxy S25 Ultra’s battery. This feat is likely achieved through the use of silicone-carbon battery technology. However, the Spark Slim remains a concept device with no firm plans for release. Tecno states that the device represents a breakthrough in ultra-thin smartphone design and performance. The company has a history of conceptualizing innovative devices, some of which have yet to reach the market. Whether this concept will see the light of day remains to be seen.