How about a portable power station? Basically a huge mobile battery with AC input. Some can switch over on power failure like a UPS. Some has USB PD (get 12V DC with the right cable) or car lighter socket (12V DC) or direct 12V DC output.

I’m talking about these, just a random article from my search:

https://techwriteredc.com/best-portable-power-stations/

The specs of your motherboard says M2_1 slot only works with 11th gen CPU but yours is 10th gen. That could be why the SATA board doesn’t work.

I’d like to use a aliexpress M.2 to RJ45 adapter on the Chromebook.

Make sure it is of the right kind. M.2 Wi-Fi slots are key E, M.2 SSD slots are key M (mostly) and cards made for 1 kind does not fit the other.

If the slot is for Wi-Fi it should have PCIe as that is what most Wi-Fi modules connect to. USB is used for Bluetooth mostly.