Development of fiber-type potassium-based cathode for sodium ion battery

A fiber-type potassium-based cathode material is developed for use in sodium ion battery without using any binder and conductive agents. This material is synthesized in a simple two-step process, including electrodeposition and hydrothermal reaction within a low temperature of 110 degrees C. This material exhibits its porous sponge-like morphology, in which the earth-abundant elements of K, Mn, and O are uniformly distributed. For its crystalline structure, the material is identified as K2Mn4O8 with a crystalline size of ca. 230 nm, suggesting its good crystallinity. In the electrochemical characterization, two irreversible redox peaks are observed during the initial charge/discharge test against sodium metal, resulting in a discharge capacity of 122 mA h/g. This indicates that K2Mn4O8 is capable of sodium-ion insertion, allowing the fiber-type potassium-based cathode to work for sodium ion battery. (C) 2016 Elsevier B.V. All rights reserved.