Tuning composite solid-state electrolyte interface to improve the electrochemical performance of lithium-oxygen battery

Abstract

Thin and flexible composite solid-state electrolyte (SSE) is considered to be a prospective candidate for lithium-oxygen (Li-O2) batteries with the aim to address the problems of unsatisfied safety, terrible durability as well as inferior electrochemical performance. Herein, in order to improve the safety and durability, a succinonitrile (SN) modified composite SSE is proposed. In this SSE, SN is introduced for eliminating the boundary between ceramic particles, increasing the amorphous region of polymer and ensuring fast ionic transport. Subsequently, the symmetric battery based on the proposed SSE achieves a long cycle life of 3000 h. Moreover, the elaborate cathode interface through the SN participation effectively reduces the barriers to the combination between lithium ions and electrons, facilitating the corresponding electrochemical reactions. As a result, the solid-state Li-O2 battery based on this SSE and tuned cathode interface achieves improved electrochemical performance including large specific capacity over 12,000 mAh g−1, enhanced rate capacity as well as stable cycle life of 54 cycles at room temperature. This ingenious design provides a new orientation for the evolution of solid-state Li-O2 batteries.

Keywords

• Solid-state Li-O2 battery
• Composite electrolyte
• Cathode interface
• Room temperature
• Succinonitrile