SnO 2–MnO 2 composite powders and their electrochemical properties

• Published in: Journal of power sources Vol. 202; pp. 291 - 298
• Main Authors: Hashem, A.M., Abuzeid, H.M., Abdel-Ghany, A.E., Mauger, A., Zaghib, K., Julien, C.M.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.03.2012
• Subjects: Cathode; Lithium batteries; Manganese dioxide; Tin oxide deposit; Manganese dioxide; Tin oxide deposit; Lithium batteries; Cathode
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/j.jpowsour.2011.11.053

► Investigating the structural and electrochemical properties of SnO 2 coated MnO 2 (cryptomelane-type) nanoparticles. ► Address the important question of the Mn dissolution in organic electrolyte and how to reduce it by surface protection. ► Magnetic experiments show the electronic configuration of the materials. ► Evidence the efficiency of the tin oxide film at the surface of cryptomelane-like α-MnO 2 particles on electrochemical tests. Nanosized cryptomelane manganese dioxide (MDO) and its SnO 2-coated product were prepared through a redox reaction between KMnO 4 and Mn(II) acetate. XRD analysis showed the cryptomelane-type structure for both materials. Chemical analysis detected the presence of K in parent and K and Sn in coated oxide. The coating was evidenced by TEM images, which display a thin layer of SnO 2 at the surface of nanosized MnO 2 particles. Vibrational spectroscopic measurements confirmed the integrity of the MnO 2 lattice. The net effect of the SnO 2 coating results in better electrochemical performance of the Li//MnO 2 cells.