Question about Lenovo Legion Y720-15IKB

Normally, new computers with a USB-C port allow charging through it. However, it is necessary to have a charger delivering a sufficient voltage and current.
Having tested my Lenovo X1 Carbon, a 5V 2A USB charger charges less than 10% in 1 night. Moreover it is necessary to have it in standby or switched off for the charge to be effective (switched on, the PC consumes more than the charger provided)

Then I think it is not possible because the PC is extremely power hungry. The power supply provides 20V for 8.5A. But the USB-C port is Thunderbold compatible. But if you were going to charge it with a 5V phone charger, I don't think it's possible. I could be wrong, as I don't have a USB power supply that can deliver that much power.