Authors: Saifon Kullyakool Khatcharin Siriwong Pittayagorn Noisong Chanaiporn Danvirutai
Publish Date: 2015/05/31
Volume: 122, Issue: 2, Pages: 665-677
Abstract
The olivine LiNiPO4 was synthesized via the calcination of the new precursor LiNiPO4·3H2O at 600 °C The precursor was obtained from lowtemperature 50 °C wet chemical reaction The results from XRD FTIR AAS/AES and TG/DTG/DTA techniques confirmed the formula of the title compounds The SEM results indicated the morphologies of the hydrate precursor as thin plate particles and the calcined product as small bead particles The BET surface area of the final calcined product at 600 °C is much higher 5807 m2 g−1 than that reported in the literature 025 m2 g−1 The kinetic triplet activation energy E preexponential factor A and the most probable mechanism function gα and the thermodynamic functions of activated complexes ΔS ≠ ΔH ≠ and ΔG ≠ for the dehydration step of LiNiPO4·3H2O were determined and discussed The mechanism of the dehydration process is the singlestep A3/2 assumed random nucleation and its subsequent growth New information namely the isobaric molar heat capacity experimental entropy enthalpy and Gibbs energy changes as function of temperature K of LiNiPO4·3H2O and LiNiPO4 was evaluated from the DSC data by thirdorder polynomial fitting and reported for the first time The calculated corresponding thermodynamic functions from kinetic parameters are compared and discussedThe authors would like to thank the Materials Chemistry Research Center Department of Chemistry The Center for Innovation in Chemistry PERCHCIC Faculty of Science Khon Kaen University the Higher Education Research Promotion and National Research University Project of Thailand Office of Higher Education Commission through the Advanced Functional Materials Cluster Khon Kaen University for financial supports
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