• Shirazi, Shahram Nouri
• Langer, Frederieke
• Sarkar, Subhajit
• Thangadurai, Venkataraman
• Schwenzel, Julian
• Zhou, Chengtian
• Chen, Bowen

Abstract

The hybrid solid-liquid electrolyte concept is one of the best approaches for counteracting the interface problems between solid electrolytes and Li anodes/cathodes. However, a solid-liquid electrolyte layer forming at the interfaces degrades battery capacity and power during a longer cycle due to highly reactive chemical and electrochemical reactions. To solve this problem in the present study, a synthetic approach is demonstrated by combining AlCl 3 Lewis acid and fluoroethylene carbonate as additives in a conventional LiPF 6 -containing carbonate-based electrolyte. This electrolyte design triggers the fluoroethylene carbonate polymerization by AlCl 3 addition and can also form a mechanically robust and ionically conductive Al-rich interphase on the surface of Li 7 La 2.75 Ba 0.25 Zr 1.75 Ta 0.25 O 12 garnet-type structured solid electrolytes, Li anodes and LiNi 0.6 Mn 0.2 Co 0.2 O 2 cathodes. Benefitting from this approach, the assembled Li symmetric cell exhibits a remarkably high critical current density of 4.2 mA cm −2 , and stable long-term cycling over 3000 h at 0.5 mA cm −2 at 25 °C. The assembled hybrid full cell shows an impressive specific capacity retention of 92.2% at 1 C till 200 cycles. This work opens a new direction in developing safe, long-lasting, and high-energy hybrid solid-state lithium-metal batteries.

Topics

• density
• impedance spectroscopy
• surface
• reactive
• forming
• Lithium
• current density