Self-assembled hollow mesoporous Co3O4 hybrid architectures: a facile synthesis and application in Li-ion batteries

We report a facile and template-free soft chemical approach that employs a low-temperature calcination treatment to synthesize a new class of materials comprising self-arranged hollow mesoporous Co3O4 and Co3O4-carbon nanotube composites. Each hollow particle is formed by a double-layered nanowall with a thickness of around 50-100 nm. The inner wall consists of a uniform amorphous layer, while the outer layer consists of self-assembled aggregates of ultrafine nanoflakes and particles. Our synthesis method is scalable and produces high yield with high reproducibility. When applied as negative electrodes in Li-ion batteries, the Co3O4-carbon nanotube composite exhibited superior performance with large reversible capacity, good cycling property and rate capability benefiting from the unique hollow and mesoporous Co3O4 particle structures as well as the hybridization with carbon nanotubes.