Synthesis of Li_xMnO_2 by chemical lithiation in an aqueous media

摘要

Li_xMnO_2 (x = 0.302) was synthesized by chemical lithiation, using a formaldehyde reducing agent and a LiOH lithium source in an aqueous media. The electrochemical properties and structural stability of the product were characterized by X-ray diffraction and charge-discharge measurements. The chemically lithiated Li_xMnO_2 had a first charge and discharge capacity of 86.2 and 265 mAh/g, respectively, with good cycling behavior. Based on the electrochemical results of the first charge, a two-step mechanism of Li_xMnO_2 lithiation is proposed. Γ-MnO_2 is first oxidized by formaldehyde, and then Li diffuses into the γ-MnO_2 lattice.