Self-assembled porous LiNi_(0.8)Co_(0.1)Mn_(0.1)O_2 cathode materials with micro/ nano-layered hollow morphologies for high-power lithium-ion batteries

摘要

The Ni2+/Li+ disorder has become one of the core problems limiting the application of LiNi0.8Co0.1Mn0.1O2 cathode material. Herein, an ammonium bicarbonate (NH4HCO3)-assisted solvo/hydrothermal method has been effectively applied to synthesize a novel hollow porous LiNi0.8Co0.1Mn0.1O2 material through adding ethylene glycol (EG) and surfactant polyvinylpyrrolidone (PVP) for the first time in this paper. The obtained cathode materials were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscope (TEM). The as-prepared material with unique spherical-like hollow structure is self assembled from nanoblock primary particles into secondary micro-architectures. The results indicate that the addition of EG and PVP not only expands the electrochemical active region of LiNi0.8Co0.1Mn0.1O2 material, but also inhibits the Ni2+/Li+ disorder and the pulverization of the as-prepared sample. The practical application indicates that the material after adding EG and PVP delivers the highest discharge capacity of 220.18 mAh g(-1) for the initial circle, and the capacity retention rate of the spherical-like cathode material is 82.36% at 20 mA g(-1) after 100 cycles. In particular, this unique microano-layered architecture effectively withstands high-rate charging and discharging process and maintains the integrity of the original structure after fast Li+ extraction and diffusion.