Synthesis of a High-Capacity α-Fe2O3@C Conversion Anode and a High-Voltage LiNi0.5Mn1.5O4Spinel Cathode and Their Combination in a Li-Ion Battery

Abstract

A Li-conversion α-Fe2O3@C nanocomposite anode and a high-voltage LiNi0.5Mn1.5O4 cathode are synthesized in parallel, characterized, and combined in a Li-ion battery. α-Fe2O3@C is prepared via annealing of maghemite iron oxide and sucrose under an argon atmosphere and subsequent oxidation in air. The nanocomposite exhibits a satisfactory electrochemical response in a lithium half-cell, delivering almost 900 mA h g-1, as well as a significantly longer cycle life and higher rate capability compared to the bare iron oxide precursor. The LiNi0.5Mn1.5O4 cathode, achieved using a modified co-precipitation approach, reveals a well-defined spinel structure without impurities, a sub-micrometrical morphology, and a reversible capacity of ca. 120 mA h g-1 in a lithium half-cell with an operating voltage of 4.8 V. Hence, a lithium-ion battery is assembled by coupling the α-Fe2O3@C anode with the LiNi0.5Mn1.5O4 cathode. This cell operates at about 3.2 V, delivering a stable capacity of 110 mA h g-1 (referred to the cathode mass) with a Coulombic efficiency exceeding 97%. Therefore, this cell is suggested as a promising energy storage system with expected low economic and environmental impacts.