NASICON-structured Na3.1Zr1.95Mg0.05Si2PO12 solid electrolyte for solid-state sodium batteries

Using stable inorganic solid electrolyte to replace organic liquid electrolyte could significantly reduce potential safety risks of rechargeable batteries. Na-superionic conductor （NASICON）-structured solid electrolyte is one of the most promising sodium solid electrolytes and can be employed in solid-state sodium batteries. In this work, a NASICON-structured solid electrolyte Na3.1Zr1.95Mg0.05Si2PO12 was synthesized through a facile solid-state reaction, yielding high sodium-ionic conductivity of 1.33 × 10-3 S.cm^-1 at room temperature. The results indicate that Mg^2＋ is a suitable and economical substitution ion to replace Zr^4＋, and this synthesis route can be scaled up for powder preparation with low cost. In addition to electrolyte material preparation, solid-state batteries with Na3.1Zr1.95Mg0.05Si2PO12 as electrolyte were assembled. A specific capacity of 57.9 mAh·g^-1 is maintained after 100 cycles under a current density of 0.5C rate at room temperature. The favorable cycling performance of the solid-state battery suggests that Na3.1Zr1.95Mg0.05Si2PO12 is an ideal electrolyte candidate for solid-state sodium batteries.

All-Solid-State Lithium Batteries with Sulfide Electrolytes and Oxide Cathodes

All-solid-state lithium batteries(ASSLBs)have attracted increasing attention due to their high safety and energy density.Among all corresponding solid electrolytes,sulfide electrolytes are considered to be the most promising ion conductors due to high ionic conductivities.Despite this,many challenges remain in the application of ASSLBs,including the stability of sulfide electrolytes,complex interfacial issues between sulfide electrolytes and oxide electrodes as well as unstable anodic interfaces.Although oxide cathodes remain the most viable electrode materials due to high stability and industrialization degrees,the matching of sulfide electrolytes with oxide cathodes is challenging for commercial use in ASSLBs.Based on this,this review will present an overview of emerging ASSLBs based on sulfide electrolytes and oxide cathodes and high-light critical properties such as compatible electrolyte/electrode interfaces.And by considering the current challenges and opportunities of sulfide electrolyte-based ASSLBs,possible research directions and perspectives are discussed.