Abstract
Spinel LiNi0.5Mn1.5O4 has widely studied as a high voltage cathode material (4.7 V) applying in high power lithium ion battery. Various methods have been developed to synthesis LiNi0.5Mn1.5O4 with different texture and crystallographic structure. In this study, nanostructured LiNi0.5Mn1.5O4 is successfully fabricated by polymer-assisted oxalate co-precipitation method. Polyacrylic acid as a dispersant agent is applied in the precipitation process to achieve the nano-scaled powder (50-100 nm) with porous texture and enhanced particle uniformity. The single grain of as-synthesized LiNi0.5Mn1.5O4 possesses well-developed octahedron morphology with clear (111) facets. None of undesired impurities, such as NiO or LixNi1-xO are found in as-fabricated powder. Besides, high-crystallinity with a well-developed cubic spinel structure is revealed in the X-ray diffraction pattern. Electrochemical performances manifest superior capacity retention of nano-sized porous LiNi0.5Mn1.5O4 with elevated cycling rate. The mechanism of particle size confining by surfactant addition is proposed and discussed in detail.