Synthesis and electrochemical properties of high-voltage LiNi0.5Mn1.5O4 electrode material for Li-ion batteries by the polymer-pyrolysis method

Abstract

A submicron LiNi0.5Mn1.5O4 cathode was synthesized via the pyrolysis of polyacrylate salts as precursor polymerized by reaction of the metal salts with acrylate acid. The structure and morphology of the resulting compound was characterized by powder X-ray diffraction (XRD) and transmission electron microscopy (TEM). The results reveal that the prepared LiNi0.5Mn1.5O4 cathode material has a pure cubic spinel structure $$({\rm Fd}\ifmmode\expandafter\bar\else\expandafter\=\fi{3}\,{\rm m})$$ and submicron-sized morphology even if calcined at 900 °C and quenched to room temperature. The LiNi0.5Mn1.5O4 electrodes exhibited promising high-rate characteristics and delivered stable discharge capacity (90 mAh/g) with excellent retention capacity at the current density of 50 mA/g between 3.5 and 4.9 V. The capacity of the LiNi0.5Mn1.5O4 electrodes remains stable even after 30 cycles at low or high current density. This polymer-pyrolysis method is simple and particularly suitable for preparation of the spinel LiNi0.5Mn1.5O4 cathode material compared to the conventional synthesis techniques.