Sodium thiophosphate electrolyte thin films prepared by pulsed laser deposition for bulk-type all-solid-state sodium rechargeable batteries

Abstract

Sodium rechargeable batteries using earth-abundant raw material sources are more suitable for wide application as compared to lithium batteries. The development of inorganic solid electrolytes with high Na-ion conductivity is indispensable to realize all-solid-state sodium batteries. The sulfide solid electrolyte with cubic Na 3 PS 4 phase has a high sodium-ion conductivity at room temperature. This research has addressed, for the first time, the preparation of Na 3 PS 4 electrolyte thin films using pulsed laser deposition, to be applied in bulk-type allsolid-state sodium batteries. The heat-treated Na 3 PS 4 thin film exhibited a conductivity of 3.5 © 10 ¹5 S cm ¹1 at 25°C and the activation energy for conduction was calculated to be 45 kJ mol ¹1 . The active material in the form of NaCrO 2 particles coated with Na 3 PS 4 thin film was applied in all-solid-state batteries, which functioned as a sodium secondary battery at room temperature.

Oxide-Based Composite Electrolytes Using Na3Zr2Si2PO12/Na3PS4 Interfacial Ion Transfer

“…NPS glass thin films were formed on the polished NASICON ceramic by PLD, conducted based on a previous report. 35 An apparatus with a KrF excimer laser (λ = 248 nm, Lambda Physik, LPXPro) was used. The pulsed laser energy was 200 mJ/pulse and the repeating frequency was 10 Hz.…”

“…The main structural unit was PS 4 3− ; some P 2 S 6 4− was also detected, with a peak profile almost the same as that reported for an NPS film on a Si substrate. 35,36 The desired NPS film was thus formed on the surfaces of the NASICON sintered ceramic. Then, gold thin films as ion-blocking electrodes were formed on the NPS films by direct current (DC) sputtering to obtain the symmetrical gold/NPS/ NASICON/NPS/gold cell.…”

“…This report describes the preparation and characterization of novel NASICON−NPS composite electrolytes with NASI-CON-rich compositions (70−90 wt %). Before composite preparation, the NASICON/NPS interfacial resistance is quantified for a model of a NASICON sintered body coated with a glassy NPS thin film, 35 prepared by pulsed laser deposition (PLD). Then, using the obtained information regarding interfaces suitable for sodium-ion transfer, oxidebased NASICON−NPS composite powders with many oxide− sulfide interfaces are prepared.…”

High-Safety Symmetric Sodium-Ion Batteries Based on Nonflammable Phosphate Electrolyte and Double Na3V2(PO4)3 Electrodes

“…Some safe electrolytes have been studied, such as aqueous, , fluorinated ethers, , ionic liquids, − organic phosphates, and solid-state electrolytes. , Among them, organic phosphate electrolytes seem to be a promising alternative owing to their low viscosity, wide electrochemical window, good solvating ability, and low cost. , Recent research studies have used organic phosphate as a single solvent to prepare a nonflammable electrolyte. , For instance, an electrolyte consists of NaFSI salt and pure tris­(2,2,2-trifluoroethyl) phosphate solvent is reported for the HC/NVP (hard carbon/Na 3 V 2 (PO 4 ) 3 ) full cell. It displayed good cycling performance with a capacity retention of 89.2% after 300 cycles at 100 mA g –1 .…”

“…Some safe electrolytes have been studied, such as aqueous, 12,13 fluorinated ethers, 14,15 ionic liquids, 16−18 organic phosphates, 19 and solid-state electrolytes. 20,21 Among them, organic phosphate electrolytes seem to be a promising alternative owing to their low viscosity, wide electrochemical window, good solvating ability, and low cost. 22,23 Recent research studies have used organic phosphate as a single solvent to prepare a nonflammable electrolyte.…”