Bioprocess-inspired preparation of silica with varied morphologies and potential in lithium storage

摘要

As one of the most delicate bioprocesses in nature, biosilicification is closely related to biosilica with various morphologies, and has provided abundant inspiration to materials synthesis. In the present study, to explore the biosilica formation process and fabricate silica with an exquisite microstructure for lithium-ion battery (LIB) electrodes, a bacterial phage (M13) is used as a biotemplate to synthesize silica with diverse morphologies: cylinders, hexagonal prisms, assemblies of smaller cylinders and nanowires. A facile ethanol bath method is conducted to coat the nanowires with nitrogen-containing carbon and carbon-coated SiO2 nanowires with mesochannels (C@msSiO2NWs) are first used as anode materials for LIBs. Attributed to the uniform carbon coating and parallel mesochannel structure, the electronic conductivity and capacity to accommodate volume variations were significantly improved. In the electrochemical performance test, the composites calcined at 750 °C (C@msSiO2NWs-750) show an impressive capacity of 653 mA h g−1 at a current density of 500 mA g−1 and stability (1000 cycles). In view of the electrochemical test outcomes, the preparation of a sophisticated structure with an outstanding potential is easily achieved via a biomimetic strategy.