Xingwen Yu, Arumugam Manthiram Sodium-Sulfur Batteries with a Polymer-Coated NASICON-type Sodium-Ion Solid Electrolyte  Xingwen Yu, Arumugam Manthiram  Matter  DOI: 10.1016/j.matt.2019.03.008 Copyright © 2019 Elsevier Inc. Terms and Conditions

Matter DOI: (10.1016/j.matt.2019.03.008) Copyright © 2019 Elsevier Inc. Terms and Conditions

Figure 1 Characterization of the Na3Zr2Si2PO12 Solid Electrolyte and the PIN Polymer (A) Illustration of the NASICON structure of Na3Zr2Si2PO12 material. (B) XRD pattern of the Na3Zr2Si2PO12 membrane (top) and the reference pattern of the Na3Zr2Si2PO12 compound (bottom). (C) SEM image of the Na3Zr2Si2PO12 membrane. (D) Molecular structure of a PIN. (E) 1H-NMR spectrum of the PIN polymer. The labels correspond to the polymer structure in (D). (F) FTIR spectrum of the PIN material. Matter DOI: (10.1016/j.matt.2019.03.008) Copyright © 2019 Elsevier Inc. Terms and Conditions

Figure 2 Characterization of the PIN-Coated Na3Zr2Si2PO12 Membrane (A) XRD pattern of the PIN material (top) and a PIN-coated Na3Zr2Si2PO12 pellet (bottom). (B) SEM image of the surface of a PIN-coated Na3Zr2Si2PO12 pellet. (C) SEM image of the cross-section of a PIN-coated Na3Zr2Si2PO12 membrane. Matter DOI: (10.1016/j.matt.2019.03.008) Copyright © 2019 Elsevier Inc. Terms and Conditions

Figure 3 Electrochemical Performances of the Na ǁ Na3Zr2Si2PO12 ǁ CNF/S and the Na ǁ PIN-Na3Zr2Si2PO12 ǁ CNF/S Cells (A) Charge-discharge profile of a Na ǁ Na3Zr2Si2PO12 ǁ CNF/S cell at the first few cycles. (B) Charge-discharge profile of a Na ǁ PIN-Na3Zr2Si2PO12 ǁ CNF/S cell at the first few cycles. (C) CV curves of a Na ǁ PIN-Na3Zr2Si2PO12 ǁ CNF/S cell at a scan rate of 0.1 mV s−1. (D) Charge-discharge curves of Na ǁ PIN-Na3Zr2Si2PO12 ǁ CNF/S cells at various C rates. (E) Specific discharge capacities and Coulombic efficiencies versus cycling number of a Na ǁ PIN-Na3Zr2Si2PO12 ǁ CNF/S cell and a Na ǁ Celgard ǁ CNF/S cell at a cycling rate of C/5. Matter DOI: (10.1016/j.matt.2019.03.008) Copyright © 2019 Elsevier Inc. Terms and Conditions

Figure 4 XPS Regional Spectra of Fresh (Top) and Cycled (Bottom) Na3Zr2Si2PO12 Membranes The cycled membrane was taken from a Na ǁ PIN-Na3Zr2Si2PO12 ǁ CNF/S cell after 100 cycles. (A) Zr 3d spectrum, (B) Si 2p spectrum, (C) P 2p spectrum. Matter DOI: (10.1016/j.matt.2019.03.008) Copyright © 2019 Elsevier Inc. Terms and Conditions

Figure 5 Characterization of the Cycled Na3Zr2Si2PO12 Membrane (A) XPS survey spectrum of the cycled Na3Zr2Si2PO12 membrane. (B) XPS S 2p spectrum of the cycled Na3Zr2Si2PO12 membrane. (C) EDS spectrum of the cycled Na3Zr2Si2PO12 membrane. (D) SEM image of the cycled Na3Zr2Si2PO12 membrane. (E–I) Elemental mappings obtained with EDS of the cycled Na3Zr2Si2PO12 membrane in the area of (D). (E) Na, (F) Zr, (G) Si, (H) P, (I) S. Matter DOI: (10.1016/j.matt.2019.03.008) Copyright © 2019 Elsevier Inc. Terms and Conditions