5v/2.4A USB-C Powerbank Kit/Box

Are there any DIY Powerbank kits that allow for an output of 2.4A? or support USB-C?

I’m finding that when I need an emergency charge of a device, more often than not it is a device that does best on 2.4A.

As USB-C becomes more common, it’d be nice to have a future-proof battery box that can work with those devices.