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Spherical Li-rich lithium manganese oxide(LMO) spinel material was synthesized by an ion implanted method assisted by polyalcohol doped with Niobium and Phosphate simultaneously.The material was characterized by scanning electron microscopy,X-ray diffraction and BET specific surface area analysis.The electrochemical performances were investigated with galvanostatic techniques and cyclic voltammetry.The synthesis process was investigated with TG/DSC.The results show that the lithium ion can be immersed into the pore of manganese dioxide at a low temperature with the ion implanted method.The prepared materials have a higher discharge capacity and better crystallization than those prepared by solid phase method.The doped Nb can improve the capacity of the Li-rich LMO spinel and reinforce the crystal growth along(111) and(400) planes.The crystal grains show circular and smooth morphology,which makes the specific surface area greatly decreased.Phosphate-doped LMO spinel exhibits good high-rate capacity and structure stability.The prepared Li_(1.09)Mn_(1.87)Nb_(0.031)O_(3.99)(PO_4)_(0.021)delivers a discharge capacity of 119mAhg~(-1) at 0.2C(1C=148mAg~(-1)) and 112.8 mAhg~(-1) at 10 C,the discharge capacity retention reaches 98% at 1 ℃ after 50 cycles at 25 ℃ and 94% at 55 ℃.
Spherical Li-rich lithium manganese oxide (LMO) spinel material was synthesized by an implanted method assisted by polyalcohol doped with Niobium and Phosphate simultaneously. The material was characterized by scanning electron microscopy, X-ray diffraction and BET specific surface area analysis. electrochemical performances were investigated with galvanostatic techniques and cyclic voltammetry. The synthesis process was investigated with TG / DSC. The results show that the lithium ion can be immersed into the pore of manganese dioxide at a low temperature with the implanted implanted method. The prepared materials have a higher discharge capacity and better crystallization than those prepared by solid phase method. doped Nb can improve the capacity of the Li-rich LMO spinel and reinforce the crystal growth along (111) and (400) planes. and smooth morphology, which makes the specific surface area greatly decreased. Phosphate-doped LMO spinel exhibits good high-r ate capacity and structure stability.The prepared Li_ (1.09) Mn_ (1.87) Nb_ (0.031) O_ (3.99) (PO_4) _ (0.021) delivers a discharge capacity of 119mAhg -1 at 0.2C (1C = 148mAg ~ (-1)) and 112.8 mAhg ~ (-1) at 10 C, the discharge capacity retention reaches 98% at 1 ° C after 50 cycles at 25 ° C and 94% at 55 ° C.