Enhanced Electrochemical Performances of Ni-Rich LiNi0.8Co0.15Al0.05O2 Cathode Materials by Ti Doping or/and Al(OH)(3) Coating

초록

To improve the electrochemical properties of Ni-rich LiNi0.8Co0.15Al0.05O2 (LiNCA) cathode material, Ti doped or/and Al(OH)(3) coated were by co-precipitation-assisted solid-phase and ball milling method was employed in this work. The morphology, structure, and electrochemical performance of the cathode materials were evaluated by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) with energy dispersive X-ray spectrometer (EDS), field emission transmission electron microscopy (FETEM) and electrochemical techniques. Ti doping is introduced into the octahedral lattice space occupied by Li-ions to widen the Li layer spacing and thereby increase the lithium diffusion kinetics. The Al(OH)(3) coating also formed a non-uniform layer on the outside of LiNCA, thereby inhibiting side reactions between the electrode and the electrolyte. As a result, the LiNCA electrode showed a high initial discharge capacity of 167.4 mAh/g. However, after 100 cycles, it showed poor cycling stability of 41.7%. In contrast, Ti doped and Al(OH)(3) coated LiNCA showed the best cycling stability of 82.2% after 100 cycles.

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