journal homepage: www.elsevier.com/locate/nanoenergy Available online at www.sciencedirect.com RAPID COMMUNICATION Flexible nano-paper-based positive electrodes for Li-ion batteries—Preparation process and properties Simon Leijonmarck a,c,n , Ann Cornell a,c , G¨ oran Lindbergh a,c , Lars W˚ agberg b,c a Department of Chemical Engineering and Technology, KTH Royal Institute of Technology, SE-100 44 Stockholm, Sweden b Department of Fibre and Polymer Technology, KTH Royal Institute of Technology, SE-100 44 Stockholm, Sweden c Wallenberg Wood Science Center, KTH Royal Institute of Technology, SE-100 44 Stockholm, Sweden Received 4 December 2012; received in revised form 18 February 2013; accepted 18 February 2013 KEYWORDS Flexible; Fibrillated; Cellulose; Lithium-ion; Battery; Electrode Abstract Flexible battery solutions is an emerging field due to a demand for bendable electronic devices. In this study, a route to make flexible positive electrodes for Li-ion batteries by utilizing nano- fibrillated cellulose (NFC) as binder material has been examined. These LiFePO 4 -based electrodes are made by filtration of a water dispersion of NFC, LiFePO 4 and Super-P carbon particles, resembling a paper-making process. The resulting electrodes show good mechanical properties both dry as well as when soaked with battery electrolyte with a stress at break of typically at 5.2 and 2.2 MPa, respectively. The cycling performance was 151 mAh/g at C/10 and 132 mAh/g at 1C for samples dried at 170 1C. The drying temperature, after the filtration step, was found to be important and to affect both the mechanical properties, rendering the electrodes more ductile at lower temperatures, as well as the electrochemical properties, causing a higher coulombic efficiency at higher temperatures. & 2013 Elsevier Ltd. All rights reserved. Introduction Flexible electronics is an emerging field including applica- tions such as wearable devices [1], ink jet-printed radio- frequency identification (RFID) tags [2,3] and roll-up reading devices [4]. To power such devices without interfering with the functionality, a need for flexible battery solutions has 2211-2855/$ - see front matter & 2013 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.nanoen.2013.02.002 n Corresponding author at: Department of Chemical Engineering and Technology, KTH Royal Institute of Technology, SE-100 44 Stockholm, Sweden. Tel.: +46 87906557. E-mail address: simonle@kth.se (S. Leijonmarck). Nano Energy (]]]]) ], ]]]–]]] Please cite this article as: S. Leijonmarck, et al., Flexible nano-paper-based positive electrodes for Li-ion batteries—Preparation process and properties, Nano Energy (2013), http://dx.doi.org/10.1016/j.nanoen.2013.02.002