University of Science and Technology Beijing - School of Materials Science and Engineering
Abstract
Na3Zr2SiPO12 was proven as a promising electrolyte in solid-state sodium batteries. However, its poor conductivity precludes application because of the large ionic resistance caused by grain boundary. Herein we proposed an additional glass phase to connect the grain boundary via Ga2O3 introduction, resulting in enhanced sodium-ion conduction and electrochemical performance. The optimized Na3Zr2SiPO12-0.15Ga electrolyte exhibits Na+ conductivity of 1.65 mS cm-1 at room temperature and a low activation energy of 0.16 eV, with 20% newly formed glass phase enclosing the grain boundary from NMR analysis. Temperature-dependent NMR line shapes and spin-lattice relaxation were used to demonstrate the estimation of Na self-diffusion and Na ion hopping. The strategy of design dense glass-ceramic electrolyte and the structure-dynamics-property correlation from NMR can be extended to wider optimization in material community.
Keywords: Fast sodium ion conductor, Nuclear magnetic resonance, Glass phase formation, Grain boundary, Solid-state battery
Lou, Chenjie and Zhang, Wenda and Liu, Jie and Gao, Yanan and Sun, Xuan and Fu, Jipeng and shi, yongchao and Xu, Ligang and Chen, Yongjin and Gao, Xiang and Kuang, Xiaojun and Su, Lei and Tang, Mingxue, Peeking the Glass Phase in the Grain Boundary of Na3zr2si2po12 by Gallium Modulation. Available at SSRN: https://ssrn.com/abstract=4523454 or http://dx.doi.org/10.2139/ssrn.4523454
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