Synthesis of Li sub()xnO sub(2) by chemical lithiation in an aqueous media

Li sub()xnO sub(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 sub()xnO sub(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 sub()xnO sub(2) lithiation is proposed. gamma -MnO sub(2) is first oxidized by formaldehyde, and then Li diffuses into the gamma -MnO sub(2) lattice.