A 72 Wh power bank should fulfill all your smartphone needs, but can a PowerCore power bank be used to charge laptops as well? Let's find out.
https://www.notebookcheck.net/Anker-PowerCore-Speed-20000-PD-Review.280272.0.html
The new thinkpads are not picky when it come to power. My T480s enjoys whatever I throw at it. 15 watt powerbank without usb pd, sure no problem. 24 watt usb pd phone charger, sure you cant game and charge but with low key usage its quite happy to charge your battery in 5 hours (btw that 51 gram charger).