Morphological evolution and kinetic enhancement of Li2FexMn1-xSiO4/C cathodes for Li-ion battery

Li 2 MnSiO 4 -based cathode materials possess reasonable work potentials and high theoretical capacities, while the practical energy/power densities are constrained by their inferior kinetics of Li + diffusion. In this work, the Pmn2 1 -structure Li 2 Fe x Mn 1-x SiO 4 /C materials were synthesized via a solvothermal method and evaluated as Li-ion cathode materials, with notable morphological evolutions and tunable crystallographic habits observed after solvothermal process. The Li 2 Fe 0.33 Mn 0.67 SiO 4 /C material delivers an initial reversible capacity of 250.2 mAh g −1 at 0.1 C (~ 1.51 Li + insertion/extraction, 1 C = 166 mA g −1 ), excellent high-rate capability (52.2 mAh g −1 at 5 C), and good long-term cyclability (64.6% after 196 cycles at 2 C). The enhanced electrochemical properties are attributed to the boosted ion/electron transports induced by preferred morphological and structural characteristics of Li 2 Fe 0.33 Mn 0.67 SiO 4 /C.