Xiaomi just teased a pretty powerful 40W wireless fast-charging system, which topped-up a phone from empty to full in a mere 40 minutes in a demonstration video. This might not be as crazy as Vivo's recently revealed 60W wireless charging, but it's still quite a lot of power to be transmitted without a cable.
According to the accompanying details from the video and Weibo, 20 minutes will see a charge of 57%, and 40 minutes will fully charge a 4,000mAh battery. For comparison, Huawei's recent devices can approach 27W, Samsung's wireless charging tops out around 15W, iPhones pull a mere 7.5W, and most basic Qi charging solutions only do 5W.
40W is a lot more power to be screaming through the air. For many, the first concern with a solution like this would be heat: Wireless charging tends to generate heat, the coils are usually stacked on top of the battery (parts that don't like heat), and more power can mean more heat. However, the details on Weibo claim that temperature shouldn't be a problem.
Only time will tell, whenever Xiaomi's new charging tech lands in a phone.