Tunable construction of multi-shell hollow SiO2 microspheres with hierarchically porous structure as high-performance anodes for lithium-ion batteries

Silica is one of the most abundant materials on the earth, and promises a high potential application in lithium ion battery (LIB). The crucial challenge for SiO2 materials is the huge volume change and poor electrical conductivity during the lithiation and delithiation process which result into the rapid capacity fading and bad cyclability. Herein, we successfully synthesized the multi-shell hollow silica microspheres (MHSM) with hierarchically porous structure via a simple sacrificial template method. The numbers of shell could be simply controlled by the precursor (Na2SiO3) loading. The multi-shell and hierarchically porous structure could endow SiO2 with large volume, good porosity and permeability. These advantages could offer not only the plentiful electrode-electrolyte reaction sites but also a “buffer” to hinder the volume expansion of silica in the Li+ charge-discharge process. The research results showed that LIB assembled with the MHSM exhibited high capacity and long cycle life. The multi-shell and hierarchically porous structures provide a novel morphology of anode materials to enhance rate capability and structural stability of high-capacity electrode materials.