reported K-ion favoured intercalating in MoS2 to form KMoS2 and the reversible reaction between KMoS2 and KxMoS2 was limited only to an intercalation process, being responsible for K storage. However, other studies reported a range of discharge products including K2S and a mixture of KxMoS2, K2S5 and K2S, suggesting K-ion storage in MoS2 might undergo a more complex mechanism than the Li and Na counterparts. Note that the kinetics of K-ion diffusion in MoS2 is sluggish due to the large size of K-ion, and this can further increase the complexity of K-ion storage mechanism.