For solid-state batteries to outperform the current lithium-ion battery technology in energy density and cost, high-performance solid electrolytes produced using low-cost precursors and scalable processes are the key. In this study, we demonstrate using inexpensive Li₃PO₄ of low conductivity 10⁻⁶ mS/cm and turning it into a fast Li⁺-ion conductor, with an ionic conductivity of $\ge$0.15 mS/cm, by engineering the anion sublattice. I⁻ anions are used to interrupt the ordered PO₄³⁻ network in Li₃PO₄, which destabilizes Li⁺-PO₄³⁻ interaction and liberates Li⁺-ions with enhanced Li⁺ mobility as evidenced by NMR relaxometry measurements. The optimal conductivity and activation energy are achieved when PO₄³⁻/I⁻ =1, in which Li⁺-ions spend equal time with PO₄³⁻and I⁻ on their diffusion paths without being trapped. Tracer-exchange NMR shows that Li₄PO₄I is more conductive than Li_3+yPO₄I_y when y $\ne$ 1. Further conductivity enhancement is possible by stabilizing pure-phase glassy Li₄PO₄I. Overall, this study shows an effective and general strategy to significantly enhance ion conduction for creating inexpensive solid electrolytes with high performance.

要使固态电池在能量密度和成本方面超越当前的锂离子电池技术，使用低成本前体和可扩展工艺生产的高性能固体电解质是关键。在这项研究中，我们展示了使用低电导率 10 ^-6 mS/cm 的廉价 Li ₃ PO ₄并将其转变为快速 Li ⁺离子导体，离子电导率为$\ge$0.15 mS/cm，通过设计阴离子亚晶格。I ^-阴离子用于中断Li ₃ PO _{4中的有序 PO 4} ^3-网络，这会破坏 Li ⁺ -PO ₄ ^3-相互作用并释放具有增强的 Li ^{+迁移率的 Li +} -离子，如 NMR 弛豫测量所证明的那样。_{当 PO 4} ^3- /I ^- =1时，获得最佳的电导率和活化能，其中 Li ⁺ - 离子与 PO ₄ ^3-和 I ^{-花费相同的时间}在它们的扩散路径上而不被困住。示踪交换 NMR 表明，当 y 时，Li ₄ PO ₄ I 比 Li _3+y PO ₄ I _{y导电性更强}$\ne$1. 通过稳定纯相玻璃态 Li ₄ PO ₄ I 可以进一步提高电导率。总体而言，本研究显示了一种有效且通用的策略，可显着提高离子传导性，以制造廉价的高性能固体电解质。