journal homepage: www.elsevier.com/locate/nanoenergy Available online at www.sciencedirect.com RAPID COMMUNICATION A new energy conversion Q3 technology based Q4 on nano-redox and nano-device processes Bin Zhu a,b,n , Peter Lund b , Rizwan Raza a,c , Janne Patakangas b , Qiu-An Huang a,d , Liangdong Fan a , Manish Singh a Q1 a Department of Energy Technology, Royal Institute of Technology, Stockholm, SE-10044, Sweden b Department of Applied Physics, Aalto University, FI-00076 Aalto, Espoo, Finland c Department of Physics, COMSATS Institute of Information Technology, Lahore 54000, Pakistan d Faculty of Physics and Electronic Technology, Hubei University, Wuhan, Hubei 430062, China Received 15 January 2013; received in revised form 8 April 2013; accepted 6 May 2013 KEYWORDS Nanoredox; Nanocomposite; Bulk hetero-junction; Semi-ion-conductor; Fuel cell Abstract Electrolyte-separator-free fuel cell (EFFC) is a new emerging energy conversion technology. The EFFC consists of a single-component of nanocomposite material which works as a one-layer fuel cell device contrary to the traditional three-layer anode–electrolyte–cathode structure, in which an electrolyte layer plays a critical role. The nanocomposite of a single homogenous layer consists of a mixture of semiconducting and ionic materials that provides the necessary electrochemical reaction sites and charge transport paths for a fuel cell. These can be accomplished through tailoring ionic and electronic (n, p) conductivities and catalyst activities, which enable redox reactions to occur on nano-particles and finally accomplish a fuel cell function. & 2013 Elsevier Ltd. All rights reserved. 1. Introduction An electrolyte-separator-free fuel cell (EFFC) consisting of a single-layer/component mixed ionic and semi-conducting material has recently been reported [1,2]. An EFFC can realize hydrogen–oxygen electrochemical reactions in the same way as a conventional membrane electrode assembly (MEA) based fuel cell (FC) in which the electrolyte layer is sandwiched between the anode layer and the cathode layers [3–5]. In a traditional MEA fuel cell, the electrolyte plays a key role both as an ionic conductor and an electron separator. The interfaces between the electrolyte and the electrodes are also a major contributor to polarization losses [6]. A single-component EFFC has fewer restrictions on the material choice than a traditional sandwich- structured fuel cell. Though the function of an EFFC has been demonstrated in practice, the underlying mechanisms have not yet been fully explained [7]. The purpose of the current study is to clarify the scientific basis of the EFFC operation, focussing on the nano-redox of the core fuel cell 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49 51 53 55 57 59 61 2211-2855/$ - see front matter & 2013 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.nanoen.2013.05.001 n Corresponding Q2 author at: Department of Energy Technology, Royal Institute of Technology, Stockholm, SE-10044, Sweden. Tel.: +46 8 7907403. E-mail addresses: binzhu@kth.se, zhubin@hubu.edu.cn (B. Zhu). Nano Energy (]]]]) ], ]]]–]]] Please cite this article as: B. Zhu, et al., A new energy conversion technology based on nano-redox and nano-device processes, Nano Energy (2013), http://dx.doi.org/10.1016/j.nanoen.2013.05.001