Engineering

Lithium (medication)

Oxide

Intercalation (chemistry)

Electrochemistry

Metallurgy

Materials science

Endocrinology

Magnesium

Inorganic chemistry

Chemical engineering

Physical chemistry

Organic chemistry

Manganese

Aqueous solution

Medicine

Chemistry

Electrode

Electrolyte

Journal of Alloys and Compounds

Layered Mn5O8 is considered as low-cost and high-voltage electrode materials for storing Na+ ions in aqueous media. Herein we provide the first report on the intercalation of Li+ and Mg2+ ions into layered Mn5O8 in non-aqueous electrolytes. The layered oxide Mn5O8 is simply prepared by a thermal decomposition of freshly precipitated γ-MnOOH at 500 °C for a short heating time. The morphology of Mn5O8 consists of well-crystalized nanoparticles with rod-like shape. The intercalation properties of Mn5O8 are examined galvanostatically in half lithium-ion cells. Two type of electrolytes are utilized: lithium and magnesium electrolytes containing 1 M LiPF6 in EC:DMC and 0.5 M MgTFSI in diglyme. Because of the layered structure, specific morphology and mixed oxidation states of manganese ions, layered Mn5O8 is able to intercalate reversibly and in high-amount both Li+ and Mg2+ ions in lithium and magnesium electrolytes. In lithium electrolyte, Mn5O8 exhibits high specific capacity (about 180 mAh/g at C/20), excellent rate capability (about 120 mAh/g at C1) and good cycling stability (the Coulombic efficiency more than 99% at C1). The mechanism of the electrochemical reaction is discussed on the basis of ex-situ HR-TEM and electron paramagnetic resonance spectroscopy (EPR). The storage capability of Mn5O8 will, most probably, be of significance for understanding the electrochemical behavior of layered Mn-based oxides in non-aqueous electrolyte.

Layered manganese oxide Mn5O8 as a structural matrix for fast lithium and magnesium intercalation