Na _ 3Zr _ 2Si2PO _ 12 (NZSP) is an inorganic solid electrolyte with the structure of sodium super-ionic conductor (NASICON), which is stable to CO2 and has the most promising development prospect. However, the solid-state Na-CO2 battery is limited by the slow dynamics of the positive electrode. The ideal anode of solid sodium-carbon dioxide battery should be conducive to the conduction of electrons, sodium ions and carbon dioxide gas. However, the point-to-point contact between the porous positive electrode and NZSP hindered ion diffusion, resulting in battery failure. In addition, the high reactivity of sodium metal always leads to interfacial parasitic reaction, which eventually leads to battery failure.
Professor Ru from Taiwan Province Provincial University, Professor Shu from Taiwan Province Provincial Normal University and Professor Yin from Institute of Metals, Chinese Academy of Sciences made use of the plastic crystal interface on the anode and the dynamic stable interface on the cathode to prepare the solid-state sodium-carbon dioxide battery as electrolyte for the first time. The related paper was published in Nanoenergy magazine, entitled "Sodium carbon dioxide battery with NASICON structure solid electrolyte".
Paper link:
/Science/Articles/ABS/PII/S 2211285521002305
In the solid-state sodium-carbon dioxide battery proposed in this paper, multi-walled carbon nanotubes modified by ruthenium nanoparticles are used as catalytic cathodes. In the cathode, porous carbon nanotubes in contact with each other form gas channels, which promotes the diffusion of CO2. In addition, sp2-type carbon on carbon nanotubes improves the conductivity of the catalyst, thus improving the reaction kinetics. Metal ruthenium nanoparticles with reduced coordination number play an important role in improving the reaction kinetics of CO2 reduction reaction (CO2RR) and CO2 precipitation reaction (CO2ER). The in-situ prepared succinonitrile-based (SN) plastic crystal interface makes Ru/CNT in close contact with NZSP, thus reducing the interface charge transfer resistance. On the negative side, the dynamic and stable interface phase is revealed by the interaction of X-ray photoelectron spectroscopy (XPS), X-ray absorption spectroscopy (XAS), Fourier transform infrared spectroscopy (FT-IR) and density functional theory (DFT). The dynamic and stable interfacial phase protects NZSP from continuous interfacial parasitic reaction, thus making it have excellent cycle performance. At the current of 100 mA/g, the complete discharge capacity of the proposed solid-state sodium -CO2 battery is 28,830 ma h/g. In addition, when the capacity is 500 ma h/g, the solid-state Na-CO2 battery can be stably cycled for more than 50 times, and when 100 Ma/g, the potential difference is small. ..
Figure 1. Summary figures
Figure 2. (a) Point-to-point contact diagram between porous anode and NZSP, which hinders ion diffusion in anode. (b) Tin wets the surface of the porous anode to promote ion diffusion. (XRD pattern of refined NZSP of Rietveld. (d) NZSP model diagram with NASICON structure. (green ZrO6 polyhedron, gray Si(P) polyhedron, blue Na 1 atom, pink Na2 atom, yellow Na3 atom) (e) Surface SEM of e)NZSP grain. (f) Nyquist diagram of Au|NZSP|Au at 25: 00.
Figure 3. (a) TEM diagram of Ru/CNT composite cathode. (b) Standard XRD patterns of Ru/CNT cathode, CNT powder and hcp-Ru. (c) X-ray absorption near-edge structure (XANES) spectra of Ru/CNT and Ru foil. (d) R space of EXAFS experimental signal weighted by Ru/CNT and Ru foil and Fourier transform (FT) k3 of the best fitting curve. (e) XRD patterns of SN with 7.5 wt% NaClO4, pure Sn and NaClO4. (f) Photographs of Sn and NaClO4 (7.5% by weight) at 50 and 25 degrees.
Figure 4. (a) National density of a)NZSP block. (b) Energy band calibration diagrams of Fermi energy levels in (00 1), (100) and (10/) three low exponential planes of b)NZSP and bcc block Na. (XPS of zr3d signal. (4) XPS of P2P signal. (XPS of si2p signal. (f) X-ray absorption near-edge structure spectrum of original NZSP and circulating NZSP P. ..
Figure 5. (a) The solid sodium-carbon dioxide battery lights up the red LED. (b) Complete discharge diagram of solid sodium-carbon dioxide battery. The charge-discharge curves of solid-state batteries at different current densities are (c) 50 mA/g, (e) 100 mA/g, (g) 200 ma/g. Solid-state batteries at different current densities (d) 50 mA/g, (f) 100 mA/g, (.
Generally speaking, the solid-state Na-CO2 battery is made of NZSP with NASICON structure, metal sodium negative electrode and Ru/CNT positive electrode with SN interface. The high conductivity of NZSP (0.8 mS/cm) promotes the application of the battery at room temperature. On the cathode side, tin plays an important role as an ionic conductor in the cathode. Without tin, the solid sodium carbon dioxide battery can't work. In addition, Ru/CNT cathode showed good catalytic activity. With the help of SN, the full discharge capacity of the battery is 28 830 mAh/g.. On the cathode side, the dynamic and stable interface was confirmed by XPS, XAS, FT-IR, EIS and DFT calculations. The dynamic and stable interfacial phase with electrical insulation properties inhibits the continuous interfacial reaction. Due to the stability of the three conductive positive and negative electrodes, the solid-state battery shows good electrochemical performance at room temperature. However, due to the shuttle corrosion of metal sodium by carbon dioxide gas, the battery eventually failed. Up to now, the high cost of solid sodium-carbon dioxide battery prepared with noble metal catalyst limits its practical application. In the future research, it is necessary to study catalysts and solid electrolytes with high cost performance to reduce the high cost of the system. (Text: Walking the World)
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