Xiaomi showcased its latest smartphone innovation today, introducing its Mi Charge Tubro tech. It's a wireless charging standard supporting the unseen-on-a-smartphone 30W speed. A 5-layer nanocrystal receiver coil was used with a conversion efficiency of 98 percent, which should help keep temperatures under control too. The company claims that should be enough to take a flat 4,000mAh battery to 50% in just 25 minutes. A full charge on the same size is achieved in 69 minute. In comparison the previous best by Xiaomi - Mi 9, which went to 20W - only charged 30% of its 3,300mAh battery in...