Re-investigation of Li insertion into the layers of Li1+x V1−y M y S2 (M=Cr, Ni and y =0 and 0.1, x ≤0.8) reveals that the transformation of Li from octahedral to tetrahedral sites in Li1+x VS2 leads to a 1.0V stabilization V(III)/V(II) plateau at 0.1C rate. Substitution of 10mol% Ni for V to form Li1+x V0.9Ni0.1S2 increases the voltage on Li insertion by 0.1–0.2V compared to nominal LiVS2, but it leads to an overall decrease in the capacity. An irreversible capacity loss on the initial charge/discharge cycle is the result of formation of an SEI layer at and below 1V versus lithium. 10mol% substitution of Cr for V (i.e. Li1+x V0.9Cr0.1S2) has no effect on the voltage, but it increases the capacity fade as the discharge/charge cycles progress.