journal homepage: www.elsevier.com/locate/nanoenergy Available online at www.sciencedirect.com RAPID COMMUNICATION High-rate V 2 O 5 -based Li-ion thin film polymer cell with outstanding long-term cyclability C. Gerbaldi a,b,n , M. Destro a , Jijeesh R. Nair a , S. Ferrari c , I. Quinzeni c , E. Quartarone c a GAME Lab, Department of Applied Science and Technology—DISAT, Institute of Chemistry, Politecnico di Torino, C.so Duca degli Abruzzi 24, 10129 Torino, Italy b Center for Space Human Robotics @Polito, Istituto Italiano di Tecnologia, Corso Trento 21, 10129 Torino, Italy c Department of Chemistry, Physical Chemistry Section, University of Pavia, Viale Taramelli 16, 27100 Pavia, Italy Received 11 June 2013; accepted 13 June 2013 Available online 20 June 2013 KEYWORDS Vanadium oxide; Thin film; Methacrylate; Multiphase electrode electrolyte composite; In situ polymerisation; Li-ion polymer battery Abstract An innovative V 2 O 5 based multiphase electrode/electrolyte composite is prepared by a fast, versatile and easily scalable UV-induced free-radical photo-polymerisation technique and its electrochemical properties are thoroughly investigated. The compact configuration consists of a highly conducting methacrylic-based polymer electrolyte directly formed over a r.f. sputtered V 2 O 5 thin film positive electrode. All-solid state thin-film Li and Li-ion cells are assembled by simply contacting the polymeric side of the compact composite with either lithium or graphite as anode in the respective cases, and long-term galvanostatic charge/discharge cycling studies are performed. The FESEM analysis after long-term cycling confirms the active role of the polymer electrolyte in stabilizing the cycling behaviour which, in turn, prolonged the life span of the cell operation. Such an assembly is one of the finest example in which a solid Li-ion polymer cell is cycled at a rate as high as 5C at ambient temperature. The results of the electrochemical and morphological studies confirm that the methodology presented here is versatile and economical to produce a well- functioning and easily up scalable Li-ion thin film battery. & 2013 Elsevier Ltd. All rights reserved. Introduction Lithium ion battery (LIB) is a well-established technology and an easily available source of cheap and clean energy, increasingly employed in the next-generation high power/ energy density devices, such as electric vehicles and hybrid electric vehicles (EV and HEV) [1], but also rapidly expanding its field of application in microenergy storage devices [2,3]. Li-based microbattery market will noticeably expand in the near future due to the surplus demand of on board power supplies for smart technologies, such as smart medicines and implantable medical tools, micro-electromechanical systems (MEMS) along with many other autonomous devices [2–5]. 2211-2855/$ - see front matter & 2013 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.nanoen.2013.06.007 n Corresponding author. Tel.: +39 011 090 4638; fax: +39 011 090 4699. E-mail address: claudio.gerbaldi@polito.it (C. Gerbaldi). Nano Energy (2013) 2, 1279–1286