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Description
Li7P2S8I, an amorphous solid state elecrolyte reveals an increase in Li+ ion conductivity when tempered.The increase in conductivity of 0.8 mS/cm (room temperature) up to 4.6 mS/cm is shown with impedance spectroscopy [1]. The tempering temperature (180°C) is 10°C lower than the melting temperature.
Despite not overcoming the melting temperature, the x-ray diffraction pattern reveals a significant difference between the non-tempered and the tempered state. This difference might be the reason for the measured increase in conductivity.
For determination of the structure, Reverse Monte Carlo simulations are used with x-ray scattering and EXAFS (K edge of S, HiSOR) measurements as boundary conditions. Additional structural information as PS4 Tetrahedrons (by 31 P NMR measurements [3]) are partly included in the simulations.
References:
[1] Spannenberger, S.; Miß, V.; Klotz, E.; Kettner, J.; Cronau, M.; Ramanayagam, A.; di Capua, F.; Elsayed, M.; Krause-Rehberg, R.; Vogel, M.; Roling, B., Solid State Ionics 341, 115040 (2019).
[2] McGreevy, R. L.; Pusztai, L., Molecular Simulations 6, 359 - 367 (1988).
[3] Miß, V.; Neuberger, S.; Winter, E.; Weiershäuser, J. O.; Gerken, D.; Xu, Y.; Krüger, S.; di Capua, F.; Vogel, M.; Schmedt auf der Günne, J.; Roling, B., Chem. Mater 34, 7721 - 7729 (2022).
