Nonisothermal Kinetics Study with Isoconversional Procedure and DAEM: LiCoPO₄ Synthesized from Thermal Decomposition of the Precursor

Abstract

The precursor of LiCoPO4 was synthesized by solid-state reaction at low-heating temperature using LiOH·H2O and NH4CoPO4·H2O as raw materials. LiCoPO4 was obtained by calcining the precursor. Based on isoconversional procedure and the distributed activation energy model (DAEM), the activation energies calculated indicate that the thermal process involves two regions, of which Region II (α = 0.38–0.90) is a kinetically complex process but Region I (α = 0.10–0.38) is a single-step process. The most probable mechanism for the Region I is two-dimensional diffusion. The distributed activation energy model (DAEM) was applied to study the Region II of decomposition process of the precursor. The distributions of activation energy, f(Eα) and values of pre-exponential factor A of the Region II of the thermal decomposition of precursor were obtained on the basis of the DAEM. The reliability of the DAEM for the Region II was tested by the comparison between experimental plots and calculated plots. The results show that the prediction of DAEM is reliable.