LiNixCoyMnzO2 (0＜x＜1

0＜y＜1

0＜z＜1) has become prosperous materials for the next generation of rechargeable lithium ion battery due to the synergistic effect of the three elements and their higher discharge voltage platform and charge-discharge capacity

but the cycle stability still need to be improved. The Ni0.5Co0.2Mn0.3(OH)2 precursor was synthesized by using the method of hydroxide co-precipitation and the lithium phosphate doped Li(Ni0.5Co0.2Mn0.3)O2 powders prepared by rheological phase reaction. The crystal structure and electrochemical performance of Li3PO4 doped Li(Ni0.5Co0.2Mn0.3)O2 powders were measured by X-ray diffraction (XRD)

energy dispersive X-ray spectroscopy (EDS)

galvanostatic charge-discharge

cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The result indicated that Li(Ni0.5Co0.2Mn0.3)O2 doped with Li3PO4 powders maintained the laminated structure of α-type-NaFeO2

and the spherical powders were agglomerated with primary particles around 1 μm. The initial discharge capacity of Li(Ni0.5Co0.2Mn0.3)O2 powders doped with 1% (mass) Li3PO4 was 188.6 mA·h·g-1 (2.2—4.6 V vs Li+/Li)

and maintained 92.9% after 30 cycles at 0.1C. Moreover

CV results showed that oxidation and reduction potential of Li(Ni0.5Co0.2Mn0.3)O2 powders doped with 1% Li3PO4 were 3.98 and 3.64 V

the polarization of the sample was 0.34 V. The EIS tests showed that the charge transfer resistance and Warburg resistance of Li(Ni0.5Co0.2Mn0.3)O2 powders doped with 1% Li3PO4 were 36.7 and 0.08661 Ω. So that

Li3PO4 components can reduce the charge transfer resistance and Li+ diffusion resistance between electrode and electrolyte

and decrease the effect of polarization

thus promote the electrochemical performance of Li(Ni0.5Co0.2Mn0.3)O2.