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KFM: Fachverband Kristalline Festkörper und deren Mikrostruktur
KFM 6: Poster
KFM 6.1: Poster
Tuesday, March 28, 2023, 17:00–19:00, P3
Electrochemical performance of KTiOAsO4 (KTA) from density functional theory — •Adriana Bocchini, Uwe Gerstmann, Tim Bartley, Hans-Georg Steinrück, Gerald Henkel, and Wolf Gero Schmidt — Universität Paderborn, 33095 Paderborn, Germany
The potassium titanyl phosphate (KTiOPO4, KTP) family has been recently suggested as a promising electrode for alkali-ion batteries [1-3]. Here, we present a study [4] based on density functional theory (DFT) that investigates the electrochemical performance of potassium titanyl arsenate (KTiOAsO4, KTA) as an electrode for potassium-ion batteries (KIBs). K-deficient K1−xTiOAsO4 (x = 0.0 − 1.0) and K-doped KTiOAsO4Kx (x = 0.0 − 0.5) is used to model cathode and anode materials, respectively. We show that KTA combines high average working voltages (up to 3.8 V) with a modest volume expansion (shrinkage) upon K (de)intercalation (both below 8%). Nudged elastic band (NEB) calculations are performed to investigate the (de)intercalation dynamics. It is shown that the most favorable K-ion (K-vacancy) diffusion path is located along the [001] direction and is characterized by activation energies lower 0.5 eV. Our results thus suggest a new application of the well-established KTA photonic crystal.
[1] Huang et al., J. Phys. Lett. 12, 2721 (2021)
[2] Huang et al., J. Chem. Phys. 156, 204702 (2022)
[3] Fedotov et al., Chem. Mater. 26, 411 (2016)
[4] Bocchini et al., Phys. Rev. Materials 6, 105401 (2022)