Controllable synthesis of a peapod-like nanostructure via nanoconfining CoFe2O4 in CMK-5 for high-performance lithium-ion batteries

Abstract

The CoFe2O4 with spinel structure has been identified as a promising anode material of lithium-ion battery because of high theoretical capacity of 914 mAh g−1, low price, high chemical durability and environmental friendliness. However, the poor electrical conductivity and significant volume change in the charge and discharge process lead to a severe capacity dropping, hindering its application. The anode architecture with spinel CoFe2O4 and mesoporous carbon CMK-5 (CoFe2O4@CMK-5) was designed through a controllable nanocasting process to overcome the problems. The CoFe2O4 nanoparticles were restrained into the hexagonal tubular mesoporous of CMK-5. The enhanced electrochemical performance benefited from the unique peapod-like structure, which could confine CoFe2O4 nanoparticles to prevent excessive volume expansion effectively. Moreover, the ordered hexagonal nanotube array could provide channels for electron transport and reserved space for electrolyte contact, enhancing cycling and rate performance. Thus, the CoFe2O4@CMK-5 displays superior retained specific capacity (836 mAh g−1) after 100 cycles.