Lattice dynamics, thermodynamics, and bonding strength of lithium-ion battery materials LiMPO₄(M = Mn, Fe, Co, and Ni): a comparative first-principles study

Heat capacity (C) and entropy of olivine-type LiFePO4 in the temperature range (2 to 773) K

“…Figure 4 presents an overview on the experimental heat capacity data measured in this work and available literature data, both theoretical (Shang et al [6]) and experimental [4] ones. In addition, all experimental heat capacity data of this work are summarized in table 8.…”

“…In order to improve the statistical as well as physical significance of the fit parameters, the lattice contribution was fitted first using the theoretical data from Shang et al [6]. Subsequently, the parameters B 3 , B 5 and B 7 were held constant and the electronic as well as the spin-wave parameters were optimized with respect to the experimental heat capacity data.…”

“…Unfortunately, the accuracy of these data is not specified. On the other hand, Shang et al [6] reported theoretical heat capacity data starting between T = (0 and 1200) K as well as Gibbs free energy, enthalpy, and entropy functions derived from firstprinciples phonon calculations. However, the theoretical results only represent the vibrational energy/entropy contribution, hence, expected electronic and especially magnetic contributions from the known antiferromagnetic transition of LFP near T = 50 K [7][8][9] were not taken into account.…”

High Voltage Cathode Materials

“…Magnetic properties of LCP and LNP show that antiferromagnetic M-O-M superexchange interactions couple the spins in planes parallel to (100) [169]. Local environment and bonding strength of the cations were studied by Raman and FTIR [172][173][174]. The voltammetry displayed an oxidation peak at *5.28 V and a reduction peak at *5.12 V (Fig.…”

Polaron-ion correlations inLixFePO4studied by x-ray nuclear resonant forward scattering at elevated pressure and temperature

“…1. Constraining the prefactor to a reasonable range based on past measurements of optical phonons 49,50,52 gives an error in the magnitude of the activation enthalpies of approximately ±10%. The slope of the curve in Fig.…”