Li Yaping, McCoy Dylan, Bordonaro Justin, Simonson Jack W, Liu Shi-Yu, Wang Sanwu
Department of Physics and Engineering Physics, The University of Tulsa, Tulsa, OK 74104, United States of America.
Department of Physics, Farmingdale State College, Farmingdale, NY 11735, United States of America.
J Phys Condens Matter. 2024 Aug 7;36(44). doi: 10.1088/1361-648X/ad68b4.
High ionic conductivity solid-state electrolytes are essential for powerful solid-state lithium-ion batteries. With density functional theory andmolecular dynamics simulations, we investigated the crystal structures of LiYBrand LiLaBr. The lowest energy configurations with uniform distribution of lithium ions were identified. Both materials have wide electrochemical stability windows (ESW): 2.64 V and 2.57 V, respectively. The experimental ESW for LiYBris 2.50 V. Through extrapolating various temperature diffusion results, the conductivity of LiYBrwas obtained at room temperature, approximately 3.9 mS cm, which is comparable to the experimental value 3.3 mS cm. LiLaBrhas a higher conductivity, a 100% increase compared with LiYBr. The activation energies of LiYBrand LiLaBrthrough the Arrhenius plot are 0.26 eV and 0.24 eV, respectively, which is also close to the experimental value of 0.30 eV for LiYBr. This research explored high ionic conductivity halide materials and will contribute to developing solid-state lithium-ion batteries.
高离子电导率固态电解质对于高性能固态锂离子电池至关重要。通过密度泛函理论和分子动力学模拟，我们研究了LiYBr和LiLaBr的晶体结构。确定了锂离子均匀分布的最低能量构型。两种材料都具有较宽的电化学稳定窗口（ESW）：分别为2.64 V和2.57 V。LiYBr的实验ESW为2.50 V。通过外推不同温度下的扩散结果，得到LiYBr在室温下的电导率约为3.9 mS/cm，这与实验值3.3 mS/cm相当。LiLaBr具有更高的电导率，与LiYBr相比提高了100%。通过阿仑尼乌斯图得到LiYBr和LiLaBr的活化能分别为0.26 eV和0.24 eV，这也接近LiYBr的实验值0.30 eV。本研究探索了高离子电导率卤化物材料，将有助于固态锂离子电池的发展。
