I have used many adapters to achieve it before, ctoc cable + ZY1276(there is an newer version ZY1280 now) + usba to dc cable + dc to thinkpad adapter. Just because of lacking soldering skills...
My current powerbank is ZMI 10 20000mAh with 45w usb-c port output. There is also a powerbank called quanhan pd20000 which can offer 65w.
I'm currently using this hack mostly with my surface, althrough recently yzxstudio has made some surface-to-usbc adapters.