Two-dimensional porous nanodisks of NiCo2O4 as anode material for high-performance rechargeable lithium-ion battery

Abstract Two-dimensional porous nanodisks of NiCo 2 O 4 have been synthesized by low temperature hydrothermal method followed by calcination at 500 °C/3 h/air. X-ray diffraction pattern confirmed the phase purity of the sample. Microstructure analysis clearly exhibits a unique porous nanodisks shape of NiCo 2 O 4 sample. Brunauer–Emmett–Teller technique is also used to investigate the surface area and pore size of the sample. Electrochemical properties are evaluated via cyclic voltammetry and Galvanostatic cycling studies. NiCo 2 O 4 as an anode exhibits excellent lithium storage capacity (673.9 mAh g −1 at 0.5C after 350 cycles; 596.9 mAh g −1 at 3.0 C after 200 cycles), high initial Coulombic efficiency (75%), long cycling stability (∼80% capacity retention at 350 cycles) and better rate capability (552.5 mAh g −1 at 4.0 C), which is much higher than the theoretical capacity of graphite (372 mAh g −1 ). This improvement can be attributed to the unique porous structure of the electrode, which allows maximum Li + ion to react with electrode material, shortens the diffusion path length and increasing the electrode/electrolyte contact area.