Optimisation of some parameters for the preparation of nanostructured LifePO4/C cathode

Abstract

LiFePO 4 /C powders have been synthesised by an easy and inexpensive mild hydrothermal method in the presence of an organic surfactant compound [hexadecyltrimethylammonium bromide (CTAB)] previously developed. The samples have been synthesised with different amounts of CTAB, and the effect of this parameter on their structural characteristics and electrochemical behaviour has been investigated. The processing of the high-resolution diffraction data in a Rietveld refining analysis and the HRTEM observations, previously not available, has put in evidence the high purity of the samples prepared and the good quality of the carbon layer covering the grains. Such layer, obtained during the firing step of the preparation in N 2 atmosphere, is very important to enhance the electronic conduction of the electrode. The sample high purity and the conduction enhancer carbon layer, along with the low grain size and high surface area, properties already put in evidence, are obtained to the maximum degree only for a sample prepared with a certain quantity of surfactant. The investigations on samples with very low and with the maximum CTAB content found out the best performing sample confirming the previous results.

Highly ionic conducting methacrylic-based gel-polymer electrolytes by UV-curing technique

“…In line with this tendency, in the recent years our research group carried out a systematic investigation on those materials which appear particularly promising for the development of lithium-based batteries with improved characteristics and performances [6][7][8][9][10].…”

All-solid-state lithium-based polymer cells for high-temperature applications

“…above 99%), after the initial cycles and at higher C rates. Although the specific capacity obtained is lower than that obtained for the same LiFePO 4 /C cathode material in common liquid electrolyte (see refs [31,32]), the cell showed good capacity retention. This is a convincing indication of a good interfacial contact between electrodes and separator.…”

“…The LiFePO 4 /C cathode material was synthesised in the form of nanostructured powder through a mild hydrothermal procedure developed at Politecnico di Torino and described in details in Meligrana et al [31,32]. The graphite anode material considered in this paper was obtained in the form of synthetic powder (particle size<20 μm) from Aldrich.…”

Lithium vanadium phosphate as cathode material for lithium ion batteries

“…To overcome these problems in electrode materials, such as LiFePO 4 , modification methods are commonly used including using nanostructures [92][93][94], coating the surface with various treatments [95,96], and metal ion doping [97][98][99] (Fig. 21).…”