High Tap Density SphericalLi[Ni0.5Mn0.3Co0.2]O2Cathode Material Synthesized via Continuous Hydroxide Coprecipitation Method for Advanced Lithium-Ion Batteries

Abstract

Spherical[Ni0.5Mn0.3Co0.2](OH)2precursor with narrow size distribution and high tap density has been successfully synthesized by a continuous hydroxide coprecipitation, andLi[Ni0.5Mn0.3Co0.2]O2is then prepared by mixing the precursor with 6% excessLi2CO3followed by calcinations. The tap density of the obtainedLi[Ni0.5Mn0.3Co0.2]O2powder is as high as 2.61 g cm−3. The powders are characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), particle size distribution (PSD), and charge/discharge cycling. The XRD studies show that the preparedLi[Ni0.5Mn0.3Co0.2]O2has a well-ordered layered structure without any impurity phases. Good packing properties of spherical secondary particles (about 12 μm) consisted of a large number of tiny-thin plate-shape primary particles (less than 1 μm), which can be identified from the SEM observations. In the voltage range of 3.0–4.3 V and 2.5–4.6 V,Li[Ni0.5Mn0.3Co0.2]O2delivers the initial discharge capacity of approximately 175 and 214 mAh g−1at a current density of 32 mA g−1, and the capacity retention after 50 cycles reaches 98.8% and 90.2%, respectively. Besides, it displays good high-temperature characteristics and excellent rate capability.