Novel NiO surface coating on LiCoO2 cathode for Li-ion batteries

Abstract

Crystalline LiCoO2 nanoparticles were coated with NiO nanocrystals. The coating was made using a one-pot strategy by solution combustion synthesis with different weight percentages. The method used is simple, economical, and easily scalable. The resulting materials were characterized morphologically, structurally, and electrochemically by transmission and scanning electron microscopy, charge/discharge cycles, rate capability, voltammetry, and electrochemical impedance spectroscopy techniques. The results showed that a uniform coating with crystalline NiO nanoparticles on the LiCoO2 was obtained. For optimal coating, the discharge capacity reached 74% retention after 100 cycles between 3.0 and 4.5V at 0.1C, while the uncoated material retained only 5% of its initial capacity. Thus, the introduced NiO coating protects the LiCoO2 electrode against the unwanted reactions that occur in contact with the electrolyte at high voltage. Therefore, the irreversible loss of the active material capacity will be minimized.