Effects of synthesis conditions on the physical and electrochemical properties of Li 1.2 Mn 0.54 Ni 0.13 Co 0.13 O 2 prepared by spray pyrolysis Miklos Lengyel a , Gal Atlas a , Dror Elhassid b , Peter Y. Luo a,1 , Xiaofeng Zhang a, 2 , Ilias Belharouak c, 3 , Richard L. Axelbaum a, * a Department of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, St. Louis, MO 63130, USA b X-Tend Energy, LLC, St. Louis, MO 63130, USA c Chemical Sciences and Engineering Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439, USA highlights  Synthesis temperatures between 350  Ce800  C are evaluated.  Excellent batch-to-batch reproducibility is obtained.  At cycle 100 discharge capacities greater than 200 mAh g 1 are obtained.  Primary particle size significantly affects electrochemical performance. article info Article history: Received 28 November 2013 Received in revised form 4 March 2014 Accepted 24 March 2014 Available online 2 April 2014 Keywords: Spray pyrolysis Lithium-ion batteries Layered lithiumenickelemanganese ecobalt-oxides Primary particle size abstract Layered Li 1.2 Mn 0.54 Ni 0.13 Co 0.13 O 2 materials were synthesized via spray pyrolysis. Synthesis conditions were varied in order to understand their effect on the electrochemical properties of the material. Three process parameters were evaluated: aerosol flow rate, reactor wall temperature and precursor concen- tration. Electrochemical results show excellent batch-to-batch reproducibility and no non-uniformities, as measured by energy dispersive X-ray spectroscopy (EDX). Phase purity is maintained for all the samples as measured by powder X-ray diffraction (XRD). The primary particle size has the most significant effect on the electrochemical performance of the materials with smaller primary particles promoting electrochemical activation and increasing capacity. Discharge capacities exceeding 200 mAh g 1 after 100 cycles at C/3 rate (where 1C ¼ 200 mAh g 1 ) are consistently obtained over a wide range of operating conditions. Spray pyrolysis is shown to be a promising, robust synthesis technique for the production of Li 1.2 Mn 0.54 Ni 0.13 Co 0.13 O 2 material, delivering excellent electrochemical performance within a wide range of process conditions. Ó 2014 Elsevier B.V. All rights reserved. 1. Introduction Layered composites of Li 2 MnO 3 and LiMO 2 (where M ¼ Mn, Ni, Co, etc.) have received significant attention, delivering reversible discharge capacities in excess of 200 mAh g 1 [1e4]. To enable commercial implementation of these materials in plug-in hybrid electric vehicles (PHEVs) and electric vehicles (EVs), a robust syn- thesis method is required. Conventional synthesis methods include co-precipitation processes, solid-state processes and solegel pro- cesses [5e7]. Recently, modified versions of these synthesis tech- niques were successfully developed, such as polymer assisted synthesis routes, solid state combustion synthesis and freeze dry- ing for producing battery materials [8e10]. Most of these processes present significant challenges that can hinder large-scale imple- mentation, such as long reaction times, compositional variations in the product, impurities and batch-to-batch inconsistencies. Solid- state synthesis methods are limited by the solid-state diffusivities and therefore can lead to impurity phases or differences in stoi- chiometry within the powder, which can compromise the elec- trochemical performance of the product [11e 14]. Solegel methods * Corresponding author. Campus Box 1180, St. Louis, MO 63130, USA. Tel.: þ1 314 935 7560; fax: þ1 314 935 5464. E-mail address: axelbaum@wustl.edu (R.L. Axelbaum). 1 Present address: Princeton University, Princeton, NJ 08544, USA. 2 Present address: Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439, USA. 3 Present address: Qatar Foundation, P.O. Box 5825 Doha, Qatar. Contents lists available at ScienceDirect Journal of Power Sources journal homepage: www.elsevier.com/locate/jpowsour http://dx.doi.org/10.1016/j.jpowsour.2014.03.113 0378-7753/Ó 2014 Elsevier B.V. All rights reserved. Journal of Power Sources 262 (2014) 286e296