An investigation on layered birnessite type manganese oxides for battery applications
نویسندگان
چکیده
Layered birnessite-type manganese oxide was prepared by a simple redox sol–gel reaction involving hydroxylamine and permanganate in alkaline medium. IR, XRD, Auger electron spectroscopy, EPR, TGA and cyclic voltammetric characteristics of the birnessites are presented. The birnessite was examined for its cathode performance in zinc-, magnesiumand lithium-based cells. Bismuth and lead exchanged birnessite show superior battery performance when compared with sodium and potassium precursors. The magnetoresistance Ž Ž . . pattern of the discharged birnessite in MgrMg ClO indicates a colossal magnetoresistance. This observation provides a scope for 4 2 further studies of examining the applicability of magnetoresistance measurement in assessing the chargerdischarge status of manganese oxides. Heat treatment of birnessite brings about distinct changes in the EPR and IR pattern. A correlation between the spectral features and electrochemical activity can be understood. q 2000 Elsevier Science S.A. All rights reserved.
منابع مشابه
Thermodynamics of manganese oxides: Sodium, potassium, and calcium birnessite and cryptomelane.
Manganese oxides with layer and tunnel structures occur widely in nature and inspire technological applications. Having variable compositions, these structures often are found as small particles (nanophases). This study explores, using experimental thermochemistry, the role of composition, oxidation state, structure, and surface energy in the their thermodynamic stability. The measured surface ...
متن کاملX-ray absorption spectroscopy of lithium insertion and de-insertion in copper birnessite nanoparticle electrodes.
The combination of ex situ X-ray diffraction (XRD) and X-ray absorption spectroscopy (XAS) measurements on 2D layered copper birnessite cathode materials for lithium ion battery applications provides detailed insight into both bulk-crystalline and localized atomic structural changes resulting from electrochemically driven lithium insertion and de-insertion. Copper birnessite electrodes that had...
متن کاملOn the Origin of the Improvement of Electrodeposited MnOx Films in Water Oxidation Catalysis Induced by Heat Treatment.
Manganese oxides (MnOx ) are considered to be promising catalysts for water oxidation. Building on our previous studies showing that the catalytic activity of MnOx films electrodeposited from aqueous electrolytes is improved by a simple heat treatment, we have explored the origin of the catalytic enhancement at an electronic level by X-ray absorption spectroscopy (XAS). The Mn L-edge XA spectra...
متن کاملThe influence of environmental conditions on kinetics of arsenite oxidation by manganese-oxides
BACKGROUND Manganese-oxides are one of the most important minerals in soil due to their widespread distribution and high reactivity. Despite their invaluable role in cycling many redox sensitive elements, numerous unknowns remain about the reactivity of different manganese-oxide minerals under varying conditions in natural systems. By altering temperature, pH, and concentration of arsenite we w...
متن کاملDecolorization of methylene blue in layered manganese oxide suspension with H2O2.
Layered birnessite-type manganese oxides (Na-OL-1) were prepared via a redox reaction involving MnO(4)(-) and Mn(2+) under markedly alkaline conditions. According to the XRD analysis, the resulting material exhibited a well-crystallized octahedral layer (OL) structure with several different phases, including β-MnOOH, α-MnOOH and γ-Mn(3)O(4). The catalyst was highly effective for the decolorizat...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 2000