A Safe and Sustainable Lithium-Ion-Oxygen Battery based on a Low-Cost Dual-Carbon Electrodes Architecture.

Abstract

People anticipate high-energy-density battery technology with better security, stability, and sustainability. By tuning the advantage of specific capacity, the lithium-metal anode is replaced with a graphite intercalation compound and a conceptual prototype lithium-ion-oxygen battery based on a low-cost dual-carbon electrodes architecture is proposed. The lithium-ion involves a (de)intercalation process into the graphite anode and an O2 /Li2 O2 redox conversion on the carbon-nanotube cathode. After a thorough examination as to the electrode compatibility with current electrolytes, a nonflammable fluorinated ether electrolyte is proposed to render a highly coordinated solvation sheath and low lithium salt concentration (1mol). Herein, the compatibility with graphite anode is investigated, which maintains high capacity retention (88.1%) after long-term lifespan (over 1 year). In view of the ultrahigh reversibility (average Coulombic efficiency over 99.93%) of the graphite anode, a lithium-ion-oxygen coin cell with high depth-of-discharge of 80% and 60% deliver a satisfactory life over 150 and 300 cycles, respectively. Moreover, systematic spectroscopy characterizations demonstrate a reversible and efficient 2e- O2 /Li2 O2 redox reaction without relying on noble-metal catalysts. Lastly, in the engineering aspect, a high-energy-density pouch cell (302.52 W h kg-1 based on the weight of the entire pouch) with cost-effective and environmentally friendly carbon-composed cell components is successfully fabricated.