Fabrication and electrochemical characterization of amorphous lithium iron silicate thin films as positive electrodes for lithium batteries I. Quinzeni a , S. Ferrari a, * , E. Quartarone a , D. Capsoni a , M. Caputo b , A. Goldoni b , P. Mustarelli a , M. Bini a a Dept. of Chemistry, University of Pavia, Viale Taramelli 16, 27100 Pavia, Italy b Elettra Sincrotrone Trieste, Strada Statale 14, Km 163.5, I-34149 Trieste, Italy highlights graphical abstract  Thin film deposition of amorphous Li/M(Fe,Mn)/Si/O by r.f. sputtering.  Good electrochemical performances: 50 mAh g 1 at 2.5 C.  The films were able to sustain about 300 cycles of chargeedischarge. article info Article history: Received 22 January 2014 Received in revised form 25 April 2014 Accepted 3 May 2014 Available online 13 May 2014 Keywords: Lithium microbattery Thin film r.f. sputtering Li 2 FeSiO 4 XPS Cyclic voltammetry abstract In this work we reported, for the first time, the preparation by radio frequency sputtering and the electrochemical characterization of Li/M/Si/O thin films (M ¼ Fe, Mn), as positive electrodes for lithium microbatteries. The deposited films were amorphous both in case of pure iron and mixed iron/manga- nese compositions. The electrochemical performances, in terms of capacity values and coulombic effi- ciency, were comparable to those currently reported for the corresponding crystalline bulk materials. In particular, capacities of the order of 50 mAh g 1 were obtained at 2.5 C with coulombic efficiency near 90% by using a standard liquid electrolyte. Our preliminary electrochemical results, together with the easiness of preparation, suggested that Li/M/Si/O thin films could be interesting candidates as cathodes in lithium microbatteries. Ó 2014 Elsevier B.V. All rights reserved. 1. Introduction The development of thin-film lithium batteries as power sour- ces for new generation micro-devices was rapidly growing over these last years. Such microsystems show several advantages, e.g. lightness, low cost and easy integration in micro-devices owing to their miniaturization [1,2]. A wide area of applications may be foreseen, ranging from microelectronics to sensors in medical and * Corresponding author. Dipartimento di Chimica, Sezione di Chimica Fisica, Università di Pavia, Viale Taramelli 16, 27100 Pavia, Italy. Tel.: þ39 382 987213; fax: þ39 382 987575. E-mail addresses: stefania.ferrari@unipv.it, S.Ferrari@warwick.ac.uk (S. Ferrari). Contents lists available at ScienceDirect Journal of Power Sources journal homepage: www.elsevier.com/locate/jpowsour http://dx.doi.org/10.1016/j.jpowsour.2014.05.012 0378-7753/Ó 2014 Elsevier B.V. All rights reserved. Journal of Power Sources 266 (2014) 179e185