An In Situ Formed Composite Surface Layer to Stabilize Na3Zr2Si2PO12/Na Interfacial Performance

• Published in: Energy & fuels 2024-10, Vol.38 (20), p.19897-19903
• Main Authors: Li, Yunpeng, Wang, Anli, Zhang, Jiayu, Zhang, Liang, Shen, Fei, Chen, Jianlin, Shen, Mengyuan, Yuan, Jiamin, Hou, Wenyan, Han, Xiaogang
• Format: Article
• Language: English
• Subjects: Batteries and Energy Storage
• ISSN: 0887-0624; 1520-5029
• DOI: 10.1021/acs.energyfuels.4c03595

Na3Zr2Si2PO12 (NZSP) is regarded as a promising solid-state electrolyte (SSE) for solid-state sodium–metal batteries (SSSMBs) due to its high ionic conductivity and stable mechanical properties. However, the poor solid–solid contact between sodium (Na) and NZSP results in a high interfacial resistance and a reduced output capacity of the SSSMBs, thus restricting its practical application. To address this issue, a SnF2 coating layer is introduced onto the surface of the NZSP with a simple drop-casting method. Then, through the in situ reaction of SnF2 and molten Na metal, a composite conductive interfacial layer can be formed with its composition analyzed by CT and XPS. This composite layer facilitates intimate contact and decreases the interfacial resistance to 2.5 Ω cm2. The critical current density is enhanced about 26 times, rising to 1.3 mA cm–2. The symmetric cell displays a stable cycle life of 2500 h at 0.2 mA cm–2 due to the advantageous interface. Moreover, the Na/SnF2@NZSP/NaNi1/3Fe1/3Mn1/3O2 full cell exhibits an excellent cycle performance.