Discovery of high entropy garnet solid-state electrolytes via ultrafast synthesis

Abstract

Multi-elemental functional oxides are crucial for addressing global energy challenges. High entropy oxides (HEO) represent an emerging class of such materials with exceptional performance, attracting significant attention in energy research. However, the concept of high entropy exponentially expands the exploration space of related materials, making the design and discovery of high-performance HEO a challenging task. The synthesis of HEO through a highly efficient and reproducible manner is urgently needed to understand their structure-property relations and develop high-performance materials. In this study, we achieved the ultrafast synthesis of high-entropy garnet Li_7+a-c-2dLa₃(A³⁺_aB⁴⁺_bC⁵⁺_cD⁶⁺_d)O₁₂ (A=Sc, Y, Bi; B=Zr, Mo, Sn, Te, Hf; C=Nb, Sb, Ta; D=W) in merely tens of seconds. Among the various garnets ranging from unary-garnet to denary-garnet, the quinary-garnet (Li_6.6La₃Zr_0.4Sn_0.4Sc_0.4Ta_0.4-Nb_0.4O₁₂) exhibits the highest ionic conductivity (3.57 × 10⁻⁴ S cm⁻¹) and low electronic conductivity (5.26 × 10⁻⁹ S cm⁻¹), with a high critical current density (2.4 mA cm⁻²) in symmetrical cells. Furthermore, via high-throughput screening of the garnet family, we discover the entropy-stabilization effect, where the synthesized garnet products are gradually stabilized into the desired pure cubic phase with increased configuration entropy. Our work demonstrates a significant step towards the rapid and accurate discovery of high-performance energy materials in the vast multi-elemental material space.