Just some mod from the creator of 0.14 Expanded Robot Technology - https://mods.factorio.com/mods/Faltease/Expanded_Robot_Tech

With the advent of infinite research for robot speed i've just included the character logistics slots and trash slots upgrades
- UPDATE-
I've just realised that carrying capacity hasn't been improved so will add that in for the next update

Logistics Slots - Up to level 10
Trash Slots - Up to level 6