講演情報
[23p-P05-40]Study of dual alkali-metal-ion coexisting NASICON-type cathode materials for sodium ion batteries
〇(D)Jiaze SUN1, Chubin WAN2, Tingli MA1 (1.Kyushu Ins. Tech., 2.Univ. Sci. Tech. BJ)
キーワード：
cathode of sodium-ion battery、Jahn-Teller effect、dual-ion substitution
NASICON fast-ionic conductors have been largely considered as a viable solution for the development of energy storage units. Due to its three-dimensional framework and high operating voltage, NASICON-type material has been extensively investigated for sodium-ion batteries.
Chemical doping is a popular technique to improve the electrochemical performances. The Mn-based NASICON-type Na4 VMn(PO4 ) 3 materials are promising cathode materials for sodium-ion batteries (SIBs) due to their environmental friendliness and cost-effectiveness. However, the unexpected Jahn-Teller effect induced by Mn 3+ and sluggish Na + diffusion kinetics in Na4 VMn(PO4 ) 3 cathodes lead to the unfavorable structural distortion and rapid capacity fading.
Some research work confirmed Heterogeneous alkali-metal-ion doping were considered as a good solution to enhance the structural stability and improve the ions transmission of cathodes in SIBs and LIBs. In this work, we demonstrated that dual-ion substitution with the Li + and K + ions, such as NASICON Nax (Li, K)1-x VMP series, induced a faster ionic conductivity, due to the enlargement of the tunnels’ bottleneck. Based on the XRD refinements, Li + and K + might occupy Na + sites or transition metal ion sites. The electrochemical properties of the Nax (Li, K)1-x VMP were evaluated through Electrochemical Impedance Spectroscopy (EIS), Cyclic Voltammetry (CV) and Galvanostatic Charge Discharge (GCD) tests. The electrochemical performance was discussed through the evaluation of experimental results from X-ray Diffraction (XRD) in combination with data from the ab-initio simulation, and the discussion was extended to a general knowledge of NASICON doping, and these results will be presented.
Chemical doping is a popular technique to improve the electrochemical performances. The Mn-based NASICON-type Na4 VMn(PO4 ) 3 materials are promising cathode materials for sodium-ion batteries (SIBs) due to their environmental friendliness and cost-effectiveness. However, the unexpected Jahn-Teller effect induced by Mn 3+ and sluggish Na + diffusion kinetics in Na4 VMn(PO4 ) 3 cathodes lead to the unfavorable structural distortion and rapid capacity fading.
Some research work confirmed Heterogeneous alkali-metal-ion doping were considered as a good solution to enhance the structural stability and improve the ions transmission of cathodes in SIBs and LIBs. In this work, we demonstrated that dual-ion substitution with the Li + and K + ions, such as NASICON Nax (Li, K)1-x VMP series, induced a faster ionic conductivity, due to the enlargement of the tunnels’ bottleneck. Based on the XRD refinements, Li + and K + might occupy Na + sites or transition metal ion sites. The electrochemical properties of the Nax (Li, K)1-x VMP were evaluated through Electrochemical Impedance Spectroscopy (EIS), Cyclic Voltammetry (CV) and Galvanostatic Charge Discharge (GCD) tests. The electrochemical performance was discussed through the evaluation of experimental results from X-ray Diffraction (XRD) in combination with data from the ab-initio simulation, and the discussion was extended to a general knowledge of NASICON doping, and these results will be presented.