Compositionally Tuned High-Entropy Li-Garnet Electrolyte for Advanced Solid-State Batteries

Abstract

The advancement of all-solid-state lithium batteries (ASSLBs) hinges on developing highly conductive and chemically stable solid electrolytes. High-entropy ceramics leveraged from high configurational entropy and synergistic interactions among the elements have emerged as a rapidly expanding class of high-entropy materials, attracting significant attention due to their exceptional properties. Here, a high-entropy Li-stuffed garnet (HEG) solid electrolyte, Li<inf>7</inf>La<inf>3</inf>Zr<inf>0.5</inf>Hf<inf>0.5</inf>Sc<inf>0.5</inf>Nb<inf>0.25</inf>Ta<inf>0.25</inf>O<inf>1</inf><inf>2</inf>, crystallizing in a highly Li+ conductive (≈1.25 × 10−4S cm−1 at room temperature) cubic phase, is reported. Electrochemical evaluations demonstrate excellent stability against lithium metal, with symmetric Li|HEG|Li cells sustaining stable Li plating/stripping beyond 550 cycles at 0.4 mA cm−2. Furthermore, full-cell integration with LiFePO<inf>4</inf> cathodes exhibits high capacity retention (≈99% over 500 cycles), confirming its potential for high-performance ASSLBs. Further, the HEG solid electrolyte is compatible with high-voltage LiMn<inf>2</inf>O<inf>4</inf> cathode (mass loading ≈16.6 mg cm−2), retaining 96% capacity over 100 cycles (at 0.2C). These findings establish a framework for tailoring high-entropy garnet electrolytes, paving the way for next-generation solid-state battery technologies. © 2025 Elsevier B.V., All rights reserved.