MLi2Ti6O14 (M= Sr, Ba, Pb): new cathode materials for magnesium-lithium hybrid batteries
Magnesium-lithium hybrid batteries (MLHBs) are playing an increasingly important role in energy storage systems owing to abundant raw materials and favorable safety characteristic. Consequently, the MLi2Ti6O14 (M= Sr, Ba, Pb) compounds have been synthesized by a sol-gel method followed with the calcination. As cathodes for MLHBs for the first time, MLi2Ti6O14 (M= Sr, Ba, Pb) show good electrochemical properties. For example, at 50 mA g-1, the specific capacities of MLi2Ti6O14 (M=Sr, Ba, Pb) after 300 cycles are 75.6, 68.2 and 76.3 mA h g-1, respectively. In addition, MLi2Ti6O14 (M=Sr, Ba, Pb) also possess outstanding rate performances. Importantly, the ion storage mechanism of MLi2Ti6O14 (M=Sr, Ba, Pb) compounds in MLHBs was studied with PbLi2Ti6O14 as the representative. These results reveal that MLi2Ti6O14 (M=Sr, Ba, Pb) have good electrochemistry reversibility, which can be used as cathodes for MLHBs.