Improving the alkali metal electrode/inorganic solid electrolyte contact via room-temperature ultrasound solid welding

• Published in: Nature communications Vol. 12; no. 1; pp. 7109 - 8
• Main Authors: Wang, Xinxin, Chen, Jingjing, Wang, Dajian, Mao, Zhiyong
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 07.12.2021; Nature Publishing Group; Nature Portfolio
• Subjects: 147/135; 639/301/299/891; 639/301/357; 639/4077/4079/891; 639/638/675; Alkali metals; Batteries; Critical current density; Dendrites; Electrodes; Electrolytes; Electrolytic cells; Humanities and Social Sciences; Lithium; Molten salt electrolytes; multidisciplinary; Rechargeable batteries; Room temperature; Science; Science (multidisciplinary); Solid electrolytes; Solid state; Ultrasonic imaging; Ultrasonic welding; Ultrasound; Welding
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-021-27473-4

The combination of alkali metal electrodes and solid-state electrolytes is considered a promising strategy to develop high-energy rechargeable batteries. However, the practical applications of these two components are hindered by the large interfacial resistance and growth of detrimental alkali metal depositions (e.g., dendrites) during cycling originated by the unsatisfactory electrode/solid electrolyte contact. To tackle these issues, we propose a room temperature ultrasound solid welding strategy to improve the contact between Na metal and Na 3 Zr 2 Si 2 PO 12 (NZSP) inorganic solid electrolyte. Symmetrical Na|NZSP | Na cells assembled via ultrasonic welding show stable Na plating/stripping behavior at a current density of 0.2 mA cm −2 and a higher critical current density (i.e., 0.6 mA cm −2 ) and lower interfacial impedance than the symmetric cells assembled without the ultrasonic welding strategy. The beneficial effect of the ultrasound welding is also demonstrated in Na|NZSP | Na 3 V 2 (PO 4 ) 3 full coin cell configuration where 900 cycles at 0.1 mA cm −2 with a capacity retention of almost 90% can be achieved at room temperature. The practical application of solid-state rechargeable alkali metal batteries is hindered by the poor contact between the metal electrode and the solid electrolyte. Here, the authors report an ultrasound solid welding strategy to favor the contact between these cells components.