EXTENDED ABSTRACT: Solid electrolytes are highly important materials for improving safety, energy density, and reversibility of electrochemical energy storage batteries. However, it is challenge to modulate the coordination structure of conducting ions, which limits the improvement of ionic conductivity and hampers further development of practical solid electrolytes. We present a skeleton-retained cationic exchange approach to produce a high-performance solid electrolyte of Li3Zr2Si2PO12 stemming from the NASICON-type superionic conductor of Na3Zr2Si2PO12. The introduced lithium ions stabilized in under-coordination structures are facilitated to pass through relatively large conduction bottlenecks inherited from Na3Zr2Si2PO12 precursor. The synthesized Li3Zr2Si2PO12 achieves a low activation energy of 0.21 eV and the high ionic conductivity of 3.59 mS·cm-1 at room temperature. Li3Zr2Si2PO12 not only inherits the satisfactory air survivability from Na3Zr2Si2PO12, but exhibits excellent cyclic stability and rate capability when applied to solid-state batteries. We have developed solid-state batteries ranging from 1 to 25 Ah, with a speciffc energy density ≥ 500 Wh/Kg. These batteries can pass safety tests such as short circuit, overcharge, over-discharge, and nail penetration. The present study opens a new avenue to regulate cationic occupancy and make new materials.

Keywords: coordination structure, skeleton-retained cationic exchange approach, oxide solid state electrolytes, high Ionic conductivity, high stability. solid state batteries.

REFERENCES:

Lei Zhu, Youwei Wang, Junchao Chen, et al. Science Advances, 8, eabj7698 (2022).