Diffusion mechanism in a sodium superionic sulfide-based solid electrolyte: Na₁₁Sn₂AsS₁₂

Abstract

Recently, in all solid state batteries, the sulfide based solid electrolytes have received increasing attention due to their high ionic conductivity, good mechanical features and better chemical stability. Therefore, in the present study, we have synthesized sodium superionic conducting novel sulfide based inorganic solid electrolyte (Na11Sn2AsS12) by solid state reaction method. The prepared solid electrolyte (Na11Sn2AsS12) has been characterized by different techniques such as XRD, SEM, XPS, TGA, EIS and LSV to study its various properties such as structure, surface morphology, thermal stability, dielectric properties, ionic conductivity and electrochemical stability window for sodium ion battery applications. The XRD analysis confirms the coexisting two phases- tetragonal and cubic with the phase fraction of 0.69 and 0.31 respectively. The SEM study reveals the irregular shape and dense morphology of solid electrolyte. On the other hand, TGA analysis shows that the prepared solid electrolyte is suitable for high temperature battery application. The ionic and transport studies confirm that the synthesized Na11Sn2AsS12 is purely ionic in nature having ionic conductivity found to be 1.14×〖10〗^(-4) S/cm and negligible electronic conductivity ~ 1.43×〖10〗^(-10) S/cm at room temperature. Furthermore, the detailed ionic conduction mechanism is studied using temperature and frequency dependent ac impedance analysis. In addition, the synthesized solid electrolyte Na11Sn2AsS12 exhibits wide electrochemical window (~7.0 V) and high diffusion coefficient (1.3×〖10〗^(-7) cm2/s) showing suitable electrolyte property for solid state sodium ion battery application.

Polysulfide Rejection Strategy in Lithium–Sulfur Batteries Using an Ion-Conducting Gel-Polymer Interlayer Membrane

“…To calculate the total conductivity of the synthesized IC-GPMs, they are sandwiched between blocking electrodes made of stainless steel with a diameter of 13 mm, and an ac signal with an amplitude of 10 mV was applied to it throughout a frequency range of 1 Hz to 40 MHz. The total conductivity (σ) of the samples is calculated by using the following formula σ = L / R normalb × A where L is the thickness of IC-GPM, A is the cross-sectional area, and R b is the bulk resistance of the sample. The Complex impedance plots and Nyquist plots were used to determine the value of R b .…”

Charge fluctuation drives anion rotation to enhance the conductivity of Na11M2PS12 (M = Si, Ge, Sn) superionic conductors

“…Sodium-ion batteries gradually attracted attention and can potentially be the alternative to lithium-ion batteries with good safety and offer the advantage of a natural abundance of sodium resources. [12][13][14][15] For the practical use of solid-state batteries, highly conductive solid electrolytes with ionic conductivities comparable to a liquid electrolyte are indispensable. [16][17][18][19] Lithium and sodium thiophosphates are widely considered to be the most suitable solid electrolytes for solid-state batteries, among many other kinds of batteries.…”

“…Sodium-ion batteries gradually attracted attention and can potentially be the alternative to lithium-ion batteries with good safety and offer the advantage of a natural abundance of sodium resources. 12–15 For the practical use of solid-state batteries, highly conductive solid electrolytes with ionic conductivities comparable to a liquid electrolyte are indispensable. 16–19…”

Surface-Coated NaNi0.815Co0.15Al0.035O2 Cathode-Based Sodium-Ion Batteries with Enhanced Performance

“…In recent years, there has been significant progress in the development of sodium-ion batteries (SIBs) owing to the abundance of sodium, its cost-effectiveness, and its similar chemical properties to those of lithium. − As a result, SIBs are emerging as the preferred option for large-scale energy storage systems. Among SIBs, layered transition metal oxides with the general form of O3 NaTMO 2 (TM = Ni, Co, Mn, Al) are the most widely used cathode materials due to their high capacity and excellent electrochemical performance. − O3-type structures have the potential to consist entirely of the full sodium content (Na x TMO 2 , x = 1).…”