Poplar branch bio-template synthesis of mesoporous hollow Co3O4 hierarchical architecture as an anode for long-life lithium ion batteries

Abstract Mesoporous hollow hierarchical structures play an important role in enhancing the lithium storage performances of Co3O4 anode materials. In this work, Co3O4 with mesoporous hollow structure has been successfully fabricated by simple impregnation and subsequently air calcination using poplar branch as bio-template. The product calcined at 600 °C (PB-Co600) perfectly duplicates the 3D aligned microchannels structure of poplar branch. Importantly, the wall of aligned microchannels in PB-Co600 is constructed by a lot of irregular cross-linked Co3O4 nanoparticles and there are abundant mesopores on the surface. As an anode, it exhibits high reversible capacity and remarkable long-cycle stability. At 0.1 A g-1, it can deliver a high specific capacity of 1153.7 mA h g-1 after 100 cycles, and even at 1 A g-1, the reversible specific capacity of 555.7 mA h g-1 can be retained after cycling 1000 times. The excellent lithium storage performance of PB-Co600 may be attributed to its unique hierarchical structure, which is not only favorable to the rapid transfer of substances and Li+ ion diffusion, but also alleviates the volume change during the charge/discharge cycle. Furthermore, the existence of oxygen vacancies and pseudo-capacitance also contributes significantly to the superior lithium storage performance of the PB-Co600 electrode. Therefore, the PB-Co600 prepared by a large-scale and eco-friendly route can be used as a potential candidate anode for LIBs.