Lithium argyrodites have gained significant attention as candidates for solid electrolytes in solid-state batteries due to their superior ionic conductivities and favorable mechanical properties. However, during charging, oxidative decomposition reactions occur at the interface between the solid electrolyte and cathode active material, which impede cell performance. In this study, transition metal substitution of the solid electrolyte is investigated with the intention of tuning the composition of the cathode electrolyte interphase (CEI) and thereby improving the cycling performance. Hence, the Li_5.5–2xZn_xPS_4.5Cl_1.5 (0 ≤ x ≤ 0.15) and Li_6–2xZn_xPS₅Br (0 ≤ x ≤ 0.15) substitution series are investigated to elucidate how substitution affects structure, Li⁺ transport, and the performance of the materials as catholytes in solid-state batteries. Corefinement of the neutron and powder X-ray diffraction data unveils the occupation of Li⁺ positions by Zn²⁺. This leads to blocking of Li⁺ transport pathways within the Li⁺ cages causing a decrease of ionic conductivities along with increasing activation energies for Li⁺ transport. By using a combination of cycling experiments, impedance spectroscopy and X-ray photoelectron spectroscopy, the composition of the CEI and the state-of-charge dependence of the CEI growth when using Li_5.5–2xZn_xPS_4.5Cl_1.5|NCM-83 composites was investigated in half-cells, revealing that Zn²⁺ substitution leads to faster decomposition kinetics and affects the CEI composition. Overall, this work explores the influence of Li⁺ substitution by Zn²⁺ on structure and transport in lithium argyrodites and the potential of transition metal substitutions as means to tune the kinetics of CEI growth, the CEI composition, and thereby cell performance.

中文翻译：

---

研究锂 Argyrodite 中过渡金属取代对结构、传输和固态电池性能的影响


银状锂因其卓越的离子电导率和良好的机械性能而作为固态电池中固体电解质的候选者而受到广泛关注。然而，在充电过程中，固体电解质和阴极活性材料之间的界面发生氧化分解反应，这阻碍了电池的性能。在本研究中，研究了固体电解质的过渡金属取代，目的是调整阴极电解质界面 （CEI） 的组成，从而提高循环性能。因此，研究了 Li_5.5-2xZn_xPS_4.5Cl_1.5 （0 ≤ x ≤ 0.15） 和 Li_6-2xZn_xPS₅Br （0 ≤ x ≤ 0.15） 取代系列，以阐明取代如何影响结构、Li⁺ 传输以及材料在固态电池中作为阴极物的性能。中子和粉末 X 射线衍射数据的细芯揭示了 Zn²⁺ 对 Li⁺ 位置的占用。这导致 Li⁺ 笼内的 Li⁺ 转运途径受阻，导致离子电导率降低，同时 Li⁺ 转运的活化能增加。通过结合循环实验、阻抗谱和 X 射线光电子能谱，确定了 CEI 的组成和 CEI 生长状态对 Li_5.5–2xZn_xPS_4.5Cl_1.5|在半电池中研究了 NCM-83 复合材料，揭示了 Zn²⁺ 取代导致更快的分解动力学并影响 CEI 组成。 总体而言，这项工作探讨了 Zn²⁺ 取代 Li⁺ 对银状锂结构和传输的影响，以及过渡金属取代作为调节 CEI 生长动力学、CEI 组成以及电池性能的潜力。