Facile synthesis of high performance LiNi0.5Mn1.4Mg0.1O4 and LiNi0.5Mn1.4Al0.1O4 by a low temperature solution combustion synthesis method

LiNi 0.5 Mn 1.4 Mg 0.1 O 4 and LiNi 0.5 Mn 1.4 Al 0.1 O 4 was synthesized by a low temperature solution combustion synthesis method at 700 °C in 30 min. Both of the two products are non-stoichiometric and disordered LiNi 0.5 Mn 1.5 O 4 spinels. The two products exhibit similar reversible capacity and excellent cycling stability at 1C rate at room temperature. The initial reversible capacity of LiNi 0.5 Mn 1.4 Mg 0.1 O 4 and LiNi 0.5 Mn 1.4 Al 0.1 O 4 are 114 mAh/g and 113 mAh/g, and remain 100.0% and 98.9% after 100 cycles at 1C, respectively. LiNi 0.5 Mn 1.4 Mg 0.1 O 4 shows better rate capability and much better cycling stability at 10C rate than these of LiNi 0.5 Mn 1.4 Al 0.1 O 4 . At 10C rate, the capacity retention of LiNi 0.5 Mn 1. 4Mg 0.1 O 4 is near 100% after 100 cycles, but the capacity retention of LiNi 0.5 Mn 1.4 Al 0.1 O 4 is only 80%. LiNi 0.5 Mn 1.4 Mg 0.1 O 4 also displays better cycling stability at 55 o C than that of LiNi 0.5 Mn 1.4 Al 0.1 O 4 . The excellent electrochemical performance of LiNi 0.5 Mn 1.4 Mg 0.1 O 4 is attributed to its higher crystallinity, larger Li + diffusion coefficient and lower charge transfer resistance.