Electrochemical performance of an all-solid-state lithium–oxygen battery under humidified oxygen

Highlight
• All solid-state lithium–air batteries
• Charge and discharge performance is greatly improved by the humidified oxygen.
• The reversible capacity is 1750 mAh g− 1 of platinum at 100 ƒÊA cm− 2.
• The reaction product contains O, H and Li.

The electrochemical performance of an all-solid-state lithium–oxygen battery was examined using a platinum patterned electrode with a lithium conducting solid electrolyte under a humidified O2 atmosphere. The cell consisted of a lithium metal anode, a protective layer of polyethylene oxide with Li(CF3SO2)2N, a lithium-conducting solid electrolyte of Li1 + x + yAlx(Ge,Ti)2 − xSiyP3 − yO12, and a sputtered platinum stripe-patterned air electrode. The open circuit voltage (OCV) of the virgin cell was 3.5 V under humidified O2 and decreased to 3.2 V after slight discharge, which is comparable with that under dry O2 (2.4 V). The cell was successfully discharged and charged at 0.1 mA cm− 2 and 60 °C. A reaction product was observed on the platinum electrode; however, it could not be identified by X-ray diffraction analysis or Raman spectroscopy, which indicated it was amorphous. Nano-secondary ion mass spectrometry (SIMS) analysis suggested that the reaction product contains Li, H, and O.