Abstract
Li-rich disordered rock-salt oxides have been extensively studied as electrode materials for lithium-ion batteries, however, their diffusion of lithium ions relies on the presence of excess lithium-ion content (>54.5 atom% relative to total metal ions). An emerging high-entropy strategy can reduce the lithium-ion content and enhance lithium-ion conductivity in sodium superionic conductor (e.g. Li(Ti,Zr,Sn,Hf)2(PO4)3). However, the high ionic conductivity in Li-stuffed disordered rock-salt oxides with low lithium-ion content is generally attributed to its cocktail effect, and the underlying mechanisms remains unclear. Here, we develop a robust Li-poor disordered rock-salt high-entropy oxide, (MgCoNiCuZn)0.75Li0.25O (HEOLi) as an artificial solid electrolyte interphase coating layer to stabilize lithium metal anodes, achieving an impressive cycling stability of over 15000 h. We elucidate a cocktail effect of HEOLi arising from its disordered structure of HEOLi, with unique crystallographic local structural distortions, delocalized electron structure, and energy gradients, enabling high Li-ion conductivity. These energy gradients reduce the overall energy barrier and promote Li+ hopping through preferential pathways within the HEOLi. This work offers insight into the cocktail effect of high-entropy and the Li-ion conduction mechanism, facilitating the rational design of conductive high-entropy ceramics.
| Original language | English |
|---|---|
| Pages (from-to) | 26-34 |
| Number of pages | 9 |
| Journal | Materials Today |
| Volume | 89 |
| DOIs | |
| State | Published - Oct 2025 |
Funding
This work was partly supported by Ministry of Science and Technology in Taiwan (MOST 112-2113-M-003-003); CPU time at Taiwan's National Center for High-performance Computing (NCHC). This work was partly supported by the Statler Endowment Fund in West Virginia University. This research used resources at the Spallation Neutron Source, a U.S. Department of Energy (DOE) Office of Science User Facility operated by the Oak Ridge National Laboratory. HZB/BESSY is acknowledged for the allocation of beamtime at beamline KMC2 (Proposal No. 222-11655-ST) and we thank beamline scientist Dr Götz Schuck for the assistance with XAS experiments. We acknowledge DESY (Hamburg, Germany), a member of the Helmholtz Association HGF, for the provision of experimental facilities. Parts of this research were carried out at PETRA III P65 and we thank Dr Edmund Welter for assisting the experiment. Beamtime was allocated for proposal I-20221092. We acknowledge the use of the WVU Shared Research Facilities for material characterization. The UCSD team (D.Z. and J.L.) also acknowledges partial support from the National Science Foundation (grant no. DMR- 2026193).