Thunderbolt 3 for laptop charging

I have a new Dell 7591 and I've broken 2 AC adapters now because they are very flimsy, they cost $90.00 each and I'd rather look at other options. Dell says I can charge it with the thunderbolt 3 port but what do I buy? I know the AC adapter is 90W. I do searches and only see usb 3.0