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In order to improve the electrochemical performance and thermal stability of Li_(1.05)Co_(1/3)Ni_(1/3)Mn_(1/3)O_2 materials,Li_(1.05)Co_(0.3)Ni_(0.35)Mn_(0.3)M_(0.05)O_2(M=Ge,Sn)cathode materials were synthesized via co-precipitation method.The structure,electrochemical performance and thermal stability were characterized by X-ray diffraction(XRD),charge/discharge cycling,cyclic voltammetry(CV),electrochemical impedance spectroscopy(EIS)and differential scanning calorimetry(DSC).ESEM showed that Sn-doped and Ge-doped slightly increased the size of grains.XRD and CV showed that Sn-doped and Ge-doped powders were homogeneous and had the better layered structure than the bare one.Sn-doped and Ge-doped improved high rate discharge capacity and cycle-life performance.The reason of the better cycling performance of the doped one was the increasing of lithium-ion diffusion rate and charge transfer rate.Sn-doped and Ge-doped also improved the mateials thermal stability.
In order to improve the electrochemical performance and thermal stability of Li_ (1.05) Co_ (1/3) Ni_ (1/3) Mn_ (1/3) O_2 materials, Li_ (1.05) Co_ (0.3) Ni_ (0.35) Mn_ 0.3) M_ (0.05) O_2 (M = Ge, Sn) cathode materials were synthesized via co-precipitation method.The structure, electrochemical performance and thermal stability were characterized by X-ray diffraction, charge / discharge cycling, cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and differential scanning calorimetry (DSC). ESEM showed that Sn-doped and Ge-doped slightly increased the size of grains. XRD and CV showed that Sn-doped and Ge- and had the better layered structure than the bare one. Sn-doped and Ge-doped improved high rate discharge capacity and cycle-life performance. the reason of the better cycling performance of the doped one was the increasing of lithium-ion diffusion rate and charge transfer rate.Sn-doped and Ge-doped also improve the mateterial thermal stability.