In a fully random disordered rocksalt with the general formula Li 1+x M 1 -x O 2 -where M is used as a generic symbol for any transition metal-a lithium excess of x ≳ 0.09 is required to ensure a long range percolating 0-TM network . It is found the connectivity of the lithium diffusion network is poorer than expected in a totally random system in almost all cases, and substantial lithium excesses are required to give good long-range connectivity of the 0-TM network . Minimising the lithium excess is desirable, as the additional lithium substitutes for the redox-active transition metal, reducing the capacity or increasing the anionredox activity which can cause voltage hysteresis and structural degradation in disordered rock salt cathodes .