Orthorhombic LiMnO_(2)nanoparticles and LiMnO_(2)nanorods have been synthesized by hydrothermal methods.LiMnO_(2)nanoparticles were synthesized by simple one-step hydrothermal method.To obtain rod-like LiMnO_(2),γ-Mn...Orthorhombic LiMnO_(2)nanoparticles and LiMnO_(2)nanorods have been synthesized by hydrothermal methods.LiMnO_(2)nanoparticles were synthesized by simple one-step hydrothermal method.To obtain rod-like LiMnO_(2),γ-MnOOH nanorods were first synthesized and then the H+ions were completely replaced by Li+resulting in LiMnO_(2)nanorods.Their electrochemical performances were thoroughly investigated by galvanostatic tests.Although the LiMnO_(2)nanoparticles have smaller size than LiMnO_(2)nanorods,the latter exhibited higher discharge capacity and better cyclability.For example,the discharge capacities of LiMnO_(2)nanorods reached 200 mA·h/g over many cycles and remained above 180 mA·h/g after 30 cycles.However,the maximum capacity of LiMnO_(2)nanoparticles was only 170 mA·h/g and quickly decreased to 110 mA·h/g after 30 cycles.Nanorods with one-dimensional electronic pathways favor the transport of electrons along the length direction and accommodate volume changes resulting from charge/discharge processes.Thus the morphology of LiMnO_(2)may play an important role in electrochemical performance.展开更多
基金the National Natural Science Foundation of China(No.90606006)the State Key Project of Fundamental Research for Nanoscience and Nanotechnology(No.2006CB932300).
文摘Orthorhombic LiMnO_(2)nanoparticles and LiMnO_(2)nanorods have been synthesized by hydrothermal methods.LiMnO_(2)nanoparticles were synthesized by simple one-step hydrothermal method.To obtain rod-like LiMnO_(2),γ-MnOOH nanorods were first synthesized and then the H+ions were completely replaced by Li+resulting in LiMnO_(2)nanorods.Their electrochemical performances were thoroughly investigated by galvanostatic tests.Although the LiMnO_(2)nanoparticles have smaller size than LiMnO_(2)nanorods,the latter exhibited higher discharge capacity and better cyclability.For example,the discharge capacities of LiMnO_(2)nanorods reached 200 mA·h/g over many cycles and remained above 180 mA·h/g after 30 cycles.However,the maximum capacity of LiMnO_(2)nanoparticles was only 170 mA·h/g and quickly decreased to 110 mA·h/g after 30 cycles.Nanorods with one-dimensional electronic pathways favor the transport of electrons along the length direction and accommodate volume changes resulting from charge/discharge processes.Thus the morphology of LiMnO_(2)may play an important role in electrochemical performance.
