Wireless charging is something we know for a while now, but you can't really call it truly wireless. Your device and charger have to practically touch each other. Xiaomi now shows a technique that allows them to be several meters away from each other.
Imagine; you are sitting on the couch with your phone and the battery goes dead. Your charger is a meter away but you don't really feel like getting up. How easy would it be if you could just charge your battery remotely, over the air. Xiaomi shows a technique that can do just that. The Mi Air Charge is a charger that can charge multiple devices up to 5 watts over a distance of several meters.
The technology only works if both transmitter and receiver use this technology. According to Xiaomi, Mi Air Charge works on the basis of beamforming just like newer WiFi standards. Radio waves are beamed to the phone and are converted into energy. For now just 5 Watts, similar to the first generation wireless Qi chargers. Fast wireless charging starts at 9 Watt, Apple's MagSafe for iPhone is 15 Watt.
Modern Tesla Tower
Xiaomi mentions in its blog post that Mi Air Charge doesn't just work with phones but also targets smartwatches, speakers and other smart devices. People have been dreaming about sending electricity over the air for years. Even by Nikola Tesla, the inventor to whom we owe the transformer and induction motor. He foresaw the large-scale transmission of electricity through the ether, from which everyone could take his or her share. His Wardenclyffe Tower, also known as Tesla Tower, was never completed and it remains to be seen whether Xiaomi's Mi Air Charge will see the light of day.