Supplementary materials for Poly(vinyl benzoate)-b-poly(diallyldimethyl ammonium TFSI)-b-poly(vinyl benzoate) triblock copolymer electrolytes for sodium batteries [Dataset]
Experimental Section: Materials: Sodium bis(fluorosulfonyl)imide (NaFSI) (Solvionic, 99.99% purity was dried at 50 °C on under vacuum overnight and stored in Ar filled glovebox. The polymer electrolyte membranes were prepared as shown in Figure 3, NaFSI and the block copolymer were dissolved in a so...
| Autores: | , , , , , , , , , |
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| Tipo de recurso: | conjunto de datos |
| Fecha de publicación: | 2024 |
| País: | España |
| Institución: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/355708 |
| Acceso en línea: | http://hdl.handle.net/10261/355708 |
| Access Level: | acceso abierto |
| Palabra clave: | Sodium batteries Sodium-air batteries Polymer electrolytes http://metadata.un.org/sdg/7 Ensure access to affordable, reliable, sustainable and modern energy for all |
| Sumario: | Experimental Section: Materials: Sodium bis(fluorosulfonyl)imide (NaFSI) (Solvionic, 99.99% purity was dried at 50 °C on under vacuum overnight and stored in Ar filled glovebox. The polymer electrolyte membranes were prepared as shown in Figure 3, NaFSI and the block copolymer were dissolved in a solvent mixture of tetrahydrofuran (THF) and acetonitrile (ACN). The solution was stirred at RT overnight and then cast on Teflon mold for solvent evaporation. The dry membranes were hot pressed and then dry at RT under vacuum, before being stored in Ar filled glovebox. Synthesis of PVB-PDADMTFSI-PVB block copolymers: The initial step of the synthesis involved synthesizing the double-functionalized chain transfer agent (CTA), known as X-DiEST-X. Diethyl meso-2,5-dibromoadipate (10 g; 27.7 mmol) was dissolved in 250 mL of 96% ethanol (EtOH) at room temperature in a 500 mL round bottom flask. Subsequently, potassium ethyl xanthogenate was added to the solution and stirred for 90 minutes. The reaction took place at room temperature for 4 hours. Upon completion, the resulting potassium bromide salt was filtered, and ethanol was removed under vacuum. The product was then dissolved in dichloromethane (DCM) and washed three times with distilled water. After evaporating the DCM, the product was dried under vacuum for 24 hours. The second step involved synthesizing the MacroCTA, denoted as X-PAm-DiEst-PAm-X, to achieve water solubility, a crucial property for the polymerization of PDADMACl. X-DiEst-X (4 g), acrylamide (12.8 g), and radical initiator AIBA (0.098 g) were dissolved in 8 mL of water and 35 mL of ethanol in a 50 mL Schlenk flask. The solution was then deoxygenated using nitrogen for 30 minutes. The reaction proceeded for one hour until a white precipitate formed. The precipitate was subsequently extracted and dried under vacuum at 40 °C overnight. Finally, the product was characterized using 1H-NMR and MALDI-TOF techniques (Figures S1 and S2). The polymerization process of the PDAMDATFSI block consisted of two stages. The first stage involved synthesizing poly-DADMACl: X-PAm-DiEst-PAm-X (2 g), AIBA (0.088 g), and PDADMACl (15.6 mL, 65 wt% aqueous solution) in a 50 mL Schlenk tube. The mixture was stirred and degassed with nitrogen for 30 minutes. The reactor was then placed in a preheated oil bath set at 60 °C. The final polymer was precipitated using a 1:1 mixture of ethanol and acetone, followed by filtration and vacuum drying at 40 °C. The product was analyzed using 1H-NMR in D2O (Figure S3). Once the PDADMACl polymer was obtained, an anion exchange was conducted to yield PDADMATFSI. PDADMACl was dissolved in distilled water and slowly added to a solution containing LiTFSI and distilled water under magnetic stirring. The resulting precipitate was then separated from the solvent, dried under vacuum at 40 °C overnight, and subsequently characterized using GPC-SEC (Figure S4). Two chain lengths of PDADMATFSI were investigated in this work: 33K and 17.5K, as shown in Table 1 To obtain the final product, PVB-b-PDADMATFSI-b-PVB triblock copolymers, PDADMATFSI and vinyl benzoate were dissolved in dimethylformamide (DMF) with AIBN as the initiator. The solution was deoxygenated with nitrogen for 30 minutes and then immersed in a preheated oil bath at 65 °C. After 24 hours of reaction, the final polymer was precipitated in cold ethanol, dried under vacuum at 40 °C for 24 hours, and the structure was characterized through 1H-NMR (Figure S5-8). MALDI-TOF: For MALDI-TOF measurements a Bruker Autoflex Speed system (Bruker, Germany) integrated with a Smartbeam-II laser (Nd:YAG, 355nm, 2 kHz) was used, with laser power adjusted during the measurements. The spectrum was acquired in linear mode with an average of 5000 shots. Samples were mixed in MeOH at a concentration of 10 mg/mL. The matrix used was 2,5-DHB, dissolved in MeOH at a concentration of 20 mg/mL. NaTFA was the cation donor (10 mg/mL dissolved in MeOH). A matrix/polymer/salt solution with 10:5:1 ratio was used and 0.5 μL were hand-spotted on the ground steel target plate. Gas Permeation Chromatography (GPC): For GPC a 1200 Infinity gel permeation chromatograph (GPC, Agilent Technologies) integrated with IR detector, a PLgel 5 mm MIXED-D column and a PLgel guard column (Agilent Technologies) was used. As eluent a 0,1 M LiTFSI/DMF solution was used and flow rate was set at 1.0 mL min-1 at 50 oC. PMMA standards (Agilent Technologies, Mp = 0.55 - 1568 x103) were used to perform calibration. Differential Scanning Calorimetry (DSC): Thermal properties of the neat block copolymers and polymer electrolyte membranes were measured by Netzsch DSC (214Polyma). All samples were characterized in the range of -100 and 150 oC, with a heating rate of 40K/min. The second heating is reported. Fourier Transform Infrared Spectroscopy (FTIR): The samples were measured by a Perkin Elmer instrument using a single diamond attenuated reflection unit. The spectra were measured in the region from 4000 to 650 cm-1. Transmission Electron Microscopy (TEM): Block copolymer films were placed into freshly prepared Procure 812 resin (ProSciTech Kirwan, QLD, C045) for 2 hours under vacuum infiltration at RT. The samples were then removed and put in resin mold (Procure 812 resin) before curing for 3 days at 580C. The resin block was sectioned using a Leica UC7 ultramicrotome to obtain silver interference (~50nm) sections and collected onto EMSFCFTH 400 mesh copper grids (ProSciTech Kirwan, QLD). Samples were imaged using a Tecnai 12 Transmission Electron Microscope (FEI, Eindhoven, The Netherlands), operating voltage of 120 kV. At all times low dose procedures were followed, using an electron dose of less than 5 electrons/Å2 for all imaging. Images were recorded using a FEI Eagle 4k x 4k CCD camera at a range of magnifications using AnalySIS v3.2 camera control software (Olympus). Solid State Magic Angle Spin Nuclear Magnetic Resonance Spectroscopy (MAS-NMR): For NMR spectroscopy, a Bruker Avance III 500 MHz ultra shield wide bore spectrometer was used. Zirconia MAS NMR rotors (diameter: 1.3 mm) were filled with samples inside Ar filled glovebox. Spectra were analysed using TopSpin software. Full-width half-maximum (fwhm) values were calculated by fitting the peaks with Gaussian/Lorentzian function. Ionic Conductivity: Ionic conductivity was measured using MTZ-35 in the frequency range of 1 Hz to 10 MHz (amplitude of 0.01 V) in the temperature range of 30 and 90 °C. The polymer electrolyte membranes were cut into 12 mm diameter round discs and andwiched between two stainless steel electrodes inside of a coin cell. The coin cell was then put in a custom-built barrel cell. All the spectra were fitted by MTlab software. Electrochemical Characterization: TNa + at 70 oC was measured with the Bruce−Vincent method, the equation used for calculation is: TNa+ = s(Δ − 0i0)/0(Δ − sis) Where ΔV = applied constant potential, I0 and Is = initial and steady-state currents, respectively, and Rio and Ris = initial and steady state interfacial resistance, respectively. Na|Na symmetric cell cycling was performed using a coin cell with the electrolyte membrane (thickness 300 μm, diameter 14 mm) sandwiched between 2 Na metal discs (diameter 10 mm). Cells were assembled inside an Ar filled glovebox. Na-metal stripping and plating were studied at different currents using a Biologic VMP3 potentiostat, data were processed with EC-Lab software. A homemade 2-electrode Swagelok-type cell was employed for Sodium-Air Battery (SAB) testing. The cell parts were dried at 60 °C overnight and then transferred to an Ar filled glovebox for assembling. The SAB cell was composed of a sodium metal disk (diameter = 12 mm, Sigma Aldrich), the polymer electrolyte membrane (diameter = 12.7 mm) and multi-doped carbon nanofibers air cathode (reported in literature). The surface of the air cathode was wetted with 50 uL of liquid electrolyte (NaTFSI:diglyme:C4mpyrTFSI in mol ratio 1:4:1) to improve contact between air cathode and polymer electrolyte membrane. Once assembled, the cells were taken outside of the Ar filled glovebox and pressurized under pure oxygen (99.99% purity). The cells were left to rest for 8 h at open circuit voltage and 50 oC. Subsequently, a current density of -75 μA cm-2 was applied, with a cut-off potential of 1.6 V.-- Under a Creative Commons license CC BY 4.0 Deed Attribution 4.0 International |
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