Combustion synthesis of inverse spinel LiNiVO 4 nano-particles using gelatine as the new fuel A. Subramania ⁎ , N. Angayarkanni, S.N. Karthick, T. Vasudevan Advanced Materials Research Lab, Department of Industrial Chemistry, Alagappa University, Karaikudi-630 003, India Received 28 July 2005; accepted 22 February 2006 Available online 27 April 2006 Abstract An inverse spinel type LiNiVO 4 nano-particles have been synthesized to be used as cathode active material for Li-ion batteries by adopting combustion method using gelatine as the new fuel, which act as an excellent combustion fuel as well as very good dispersing agent. The optimum temperature for the phase formation and/or complete crystallization of the precursor sample is found out by TG/DTA analysis. The structural property of the synthesized product is characterized by X-ray diffraction and FTIR spectroscopy studies. The morphology and the particle size of the synthesized powder is analyzed by TEM studies. The electrochemical reversibility and the charge/discharge studies of the synthesized LiNiVO 4 are examined by fabricating lithium-ion polymer cell in the configuration of C/LiNiVO 4 employing Li + ion conducting PVdF-HFP based micro-porous polymer electrolyte. © 2006 Elsevier B.V. All rights reserved. Keywords: Combustion synthesis; Gelatine; Lithium nickel vanadate; Inverse spinel compound; Li-ion batteries 1. Introduction Over the past decade tremendous research has been conducted on cathode materials for their use in Li-ion batteries. Among them, LiNiVO 4 and LiCoVO 4 have been proposed as cathode active materials for modern rechargeable Li-ion batteries [1]. These inverse spinel materials are very attractive due to their theoretical capacity of about 148 mA h g -1 and high voltage in the range of 4.2–4.8 V over the other transition metal oxides such as LiCoO 2 [2], LiNiO 2 [3] and LiMn 2 O 4 [4] and their upper voltage limits are in the range of 4.1–4.5 V. Of late, attempts are being made to obtain phase pure LiNiVO 4 by many researchers since synthesis is the key step towards the successful development of materials with good physical as well as electrochemical properties. Hence maximum efforts need to be put forth in selecting techniques for the synthesis of better performing LiNiVO 4 . Several methods such as solid-state thermal reaction, hydrothermal, coprecipitation and combustion [5–8] have been adopted for the synthesis of these oxide materials. Among them, combustion technique is the most widely used method. Nevertheless, this technique has the drawback of producing highly agglomerated particles. To overcome this drawback, we have reported very recently a low temperature sol–gel thermolysis technique for the large- scale synthesis of well-dispersed nanocrystalline cubic spinel LiSr x Mn 2-x O 4 powder using urea and poly vinyl alcohol [9]. In this paper, we report at the very first, the synthesis of LiNiVO 4 nano-particles in a very pure state by gelatine combustion technique. This gelatine plays an important role during the synthesis, which act as an excellent fuel as well as very good dispersing agent rather than all other conventional fuels to control the particle size and also prevents the particles from aggregation during the combustion process. The optimum temperature for the phase formation and/or complete crystalli- zation of the precursor sample is found out by TG/DTA analysis. The structural property of the synthesized product is characterized by X-ray diffraction and FT-IR spectroscopy studies. The morphology and the particle size of the synthesized powder is analyzed by transmission electron microscope (TEM). Finally the electrochemical reversibility and charge– Materials Letters 60 (2006) 3023 – 3026 www.elsevier.com/locate/matlet ⁎ Corresponding author. E-mail address: a_subramania@yahoo.co.in (A. Subramania). 0167-577X/$ - see front matter © 2006 Elsevier B.V. All rights reserved. doi:10.1016/j.matlet.2006.02.094