Hydrothermal synthesis of cathode materials for rechargeable lithium ion battery

Abstract

The Lithium-ion batteries are electrochemical systems based on the use of intercalation compounds supported on porous structures with different characteristics. The Li-ion battery operates by intercalation of Li+ cations in materials, for migration from the cathode to the anode. Different materials are used as cathode, for example, mixed oxides of transition metals (LiMO2, where M: Mn, Co and / or Ni) [1-2], and lithium iron phosphate (LiFePO4) [3] or other materials [4-5]. In this paper the preparation of Li-Ni-Co-Mn oxides by hydrothermal synthesis is presented; being a simple, low cost and low temperatures process; that produces highly homogeneous materials. A solution containing nitrate of cobalt, nickel and manganese, sodium hydroxide and lithium are used as precursor solution; this is introduced into an autoclave at 180°C. Then the precipitates that have been obtained are combusted in an oxygen atmosphere. Optical techniques (as DRX, SEM and TEM) are used to characterize the prepared material. The electrochemical performance of mixed oxides as active cathode materials in lithium-ion batteries are studied by electrochemical techniques such as charge-discharge cycles, galvanostatic discharge at different currents, cyclic voltammetry and electrochemical impedance spectroscopy.