Recently, a number of smartphones from Chinese brands have been outfitted with batteries boasting capacities of 8,000mAh or even higher. In the meantime, Samsung SDI, Samsung's battery - making subsidiary, is in the process of testing a dual - cell silicon - carbon battery for smartphones. This battery claims to have a total capacity of up to 20,000mAh, which has garnered substantial attention within the industry.

This innovative battery employs nanostructured silicon - carbon composite material as the negative electrode. In theory, it can accommodate ten times the number of lithium ions compared to graphite negative electrodes. As a result, it significantly boosts the battery's capacity while simultaneously reducing its overall thickness. The battery currently under testing is composed of a main cell (with a capacity of 12,000mAh and a thickness of 6.3mm) and an auxiliary cell (with a capacity of 8,000mAh and a thickness of 4mm).

However, test results have shown that the auxiliary cell experiences around 80% bulging. This indicates a lack of sufficient structural stability, making it highly improbable for the battery to enter mass production in the near future. At present, Samsung's flagship models, like the Galaxy S25 Ultra, still rely on a 5,000mAh battery. It is anticipated that the upcoming Galaxy S26 Ultra will also maintain this battery capacity.