Not a patented IC; just two mosfets back to back.
This site refers to it as a "mosfet true switch" (scroll down) but I think it's more commonly referred to as an "ideal diode". Well, whatever, it's two mosfets back to back.
For a battery cut off application it's just a matter of turning off the gate drive when the voltage drops below a certain level. Pololu uses a physical switch, but an appropriate voltage reference, zener diode, Arduino pin, or three pin shunt regulator (TLV431) would work just as well.