Synthesis and understanding of Na11Sn2PSe12 with enhanced ionic conductivity for all-solid-state Na-ion battery

Zhaoxin Yu, Shun Li Shang, Daiwei Wang, Yuguang C. Li, Hemant P. Yennawar, Guoxing Li, Haw Tyng Huang, Yue Gao, Thomas E. Mallouk, Zi Kui Liu, Donghai Wang

Research output: Contribution to journalArticle

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Abstract

All-solid-state Na-ion batteries (NIBs) that incorporate nonflammable solid-state electrolytes and an inexhaustible alkali metal offer a potential solution to the safety and cost concerns associated with conventional Li-ion batteries that use liquid electrolytes. Na-ion solid-state electrolytes (SSEs) with high ionic conductivity are the key to success for all-solid-state NIBs. Here, we report a new Na-ion SSE, Na11Sn2PSe12, with a superior grain conductivity of 3.04 mS cm−1 and a total ionic conductivity of 2.15 mS cm−1 at 25 °C. Single-crystal X-ray diffraction, first-principles phonon calculations, and the proposed bonding energy model indicate that its superior ionic conductivity stems from the presence of a high density of dispersive Na+ vacancies, three-dimensional Na-ion conduction pathways, and a low bonding energy of the Na+ ion with its neighboring atoms. Na11Sn2PSe12 is used for the first time as the electrolyte in all-solid-state Na-Sn/TiS2 battery cell, which shows excellent rate performance and delivers a high reversible capacity of 66.2 mAh (g of TiS2)−1 after 100 cycles with cycling retention of 88.3% at a rate of 0.1 C at room temperature.

Original languageEnglish (US)
Pages (from-to)70-77
Number of pages8
JournalEnergy Storage Materials
Volume17
DOIs
StatePublished - Feb 2019

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All Science Journal Classification (ASJC) codes

  • Renewable Energy, Sustainability and the Environment
  • Materials Science(all)
  • Energy Engineering and Power Technology

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