Improved structure stability and performance of a LiFeSO4F cathode material for lithium-ion batteries by magnesium substitution

The electrochemical inactive Mg 2+ substituted the Fe(2) site of LiFeSO 4 F. The Mg 2+ could improve the structure stability during the lithium ion de-/insertion, thus the Mg-substituted LiFeSO 4 F exhibits outstanding electrochemical cycling stability.