Because the default power of USB 3.1 is at max. 4,5 Watt I thought I could use a splitter or Y cable for that. The idea is that one USB-A male connector transfers the data (10 Gbit) and power and the other USB-A male connector the power in addition. So you could get 9 Watt out of two ports.
But I only found one cable from CY and here it is one time USB 2.0 only and on the other side they write USB 3.1. Aren‘t there any other options?
Another alternative would be an USB hub. But one with external power supply, 10 Gbit and more than 900 mA per port would start at 90 $ ... (e.g. IB-HUB1477-C31).
Is it really that complicated?