In situ formed LiF-Li_(3)N interface layer enables ultra-stable sulfide electrolyte-based all-solid-state lithium batteries

Sulfide solid electrolytes are promising for high energy density and safety in all-solid-state batteries due to their high ionic conductivity and good mechanical properties.However,the application of sulfide solid electrolytes in all-solid-state batteries with lithium anode is restricted by the side reactions at lithium/electrolytes interfaces and the growth of lithium dendrite caused by nonuniform lithium deposition.Herein,a homogeneous LiF-Li_(3)N composite protective layer is in situ formed via a manipulated reaction of pentafluorobenzamide with Li metal.The LiF-Li_(3)N layer with both high interfacial energy and interfacial adhesion energy can synergistically suppress side reactions and inhibit the growth of lithium dendrite,achieving uniform deposition of lithium.The critical current densities of Li_(10)GeP_(2)S_(12)and Li_(6)PS_(5)Cl are increased to 3.25 and 1.25 mA cm^(-2)with Li@LiF-Li_(3)N layer,which are almost triple and twice as those of Li-symmetric cells in the absence of protection layer,respectively.Moreover,the Li@LiF-Li_(3)N/Li10GeP2S12/Li@LiF-Li_(3)N cell can stably cycle for 9000 h at 0.1 mA cm^(-2)under 0.1 mA h cm^(-2),and Li@LiF-Li_(3)N/Li_(6)PS_(5)Cl/Li@LiF-Li_(3)N cell achieves stable Li plating/stripping for 8000 h at 0.1 mA cm^(-2)under10 m A h cm^(-2).The improved dynamic stability of lithium plating/stripping in Li@LiF-Li_(3)N/Li_(10)GeP_(2)S_(12)or Li_(6)PS_(5)Cl interfaces is proved by three-electrode cells.As a result,LiCoO_(2)/electrolytes/Li@LiF-Li_(3)N batteries with Li_(10)GeP_(2)S_(12)and Li_(6)PS_(5)Cl exhibit remarkable cycling stability of 500 cycles with capacity retentions of 93.5%and 89.2%at 1 C,respectively.

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.

Air exposure towards stable Li/Li_(10)GeP_(2)S_(12) interface for all-solid-state lithium batteries

Moist air is a great challenge for manufacturing sulfide-based all-solid-state lithium batteries as the water in air will lead to severe decomposition of sulfide electrolytes and release H2S gas.However,different with direct reaction with water,short-period air exposure of Li_(10)GeP_(2)S_(12) sulfide electrolyte with controlled humidity can greatly enhance the stability of Li_(10)GeP_(2)S_(12) against lithium metal,thus realizing stable Li_(10)GeP_(2)S_(12) based all-solid-state lithium metal batteries.During air exposure,partial hydrolysis reaction occurs on the surface of Li_(10)GeP_(2)S_(12) pellets,rapidly generating a protective decomposition layer of Li4P2S6,GeS2 and Li2HPO3 in dozens of seconds.This ionically conductive but electronically insulation protecting layer can effectively prevent the severe interface reaction between Li_(10)GeP_(2)S_(12) and lithium metal during electrochemical cycling.The Li/40s-air-exposed Li_(10)GeP_(2)S_(12)/Li cell shows long cycling stability for 1000 h.And the LiCoO_(2)/40s-air-exposed Li_(10)GeP_(2)S_(12)/Li batteries present good rate capability and long cyclic performances,showing capacity retention of 80%after 100 cycles.