CO2 assisted synthesis of highly dispersed Co3O4 nanoparticles on mesoporous carbon for lithium ion battery

Abstract

Co3O4 nanoparticles were uniformly dispersed onto the mesoporous carbon support (Co3O4/mC) using a facile process in CO2–expanded ethanol (CE) solution. During the synthesis, CO2 played the dual roles, one is to provide a simple physical expansion to evenly disperse the precursors onto the mesoporous carbon support, and the other is to offer some chemical groups such as CO32− to facilitate the complete and uniform deposition through the coordination to the metallic cations with these anions. When used as anode material for lithium ion batteries (LIBs), the Co3O4/mC synthesized in CO2-expanded ethanol solution exhibited larger surface area and better cycle performance compared with the reference sample synthesized in pure ethanol. The enhanced cycle performance could be attributed to the synergistic effects between the superior structures of mesoporous C support and the highly dispersed Co3O4 nanoparticles. More importantly, the synthesis of Co3O4/mC composite in CE solution was green and highly efficient, avoiding the use of precipitant and the aggregation of Co3O4, which would definitely enrich the strategies for the fabrication of carbon-based transition-metal oxide composites with great applications.