Ab-initio modelling of new cathode material for Li-ion battery based on the Ti substituted Li2Fe(SO4)2

Abstract

This work demonstrates the battery-related properties of Li2Fe(SO4)2 and its Fe site Ti substituted derivatives (Li2Ti0.5Fe0.5(SO4)2 and Li2Ti(SO4)2) using ab-initio calculations. The calculated voltage profile of all these systems clearly indicates the increase of voltage with delithiation. Even though the average voltage values of Ti-substituted systems gradually changes with the Ti concentration, they are still in the range of requirement for a good cathode material. In most of the cases, Ti substitutions increase the specific capacity and energy density of Li2Fe(SO4)2. The negative enthalpy of formation implies that all the considered systems are thermodynamically stable. These results indicate that Ti-substituted Li2Fe(SO4)2 could be a potential cathode material for rechargeable Li-ion batteries.This work demonstrates the battery-related properties of Li2Fe(SO4)2 and its Fe site Ti substituted derivatives (Li2Ti0.5Fe0.5(SO4)2 and Li2Ti(SO4)2) using ab-initio calculations. The calculated voltage profile of all these systems clearly indicates the increase of voltage with delithiation. Even though the average voltage values of Ti-substituted systems gradually changes with the Ti concentration, they are still in the range of requirement for a good cathode material. In most of the cases, Ti substitutions increase the specific capacity and energy density of Li2Fe(SO4)2. The negative enthalpy of formation implies that all the considered systems are thermodynamically stable. These results indicate that Ti-substituted Li2Fe(SO4)2 could be a potential cathode material for rechargeable Li-ion batteries.