Facile synthesis of porous Co3O4 nanosheets containing abundant oxygen vacancies for boosted lithium-ion storage

Nanosized cobalt (II, III) oxide (Co 3 O 4 ) is a promising anode material in virtue of its relatively high theoretical capacity. In this study, nanosized Co 3 O 4 was fabricated by facile hydrothermal method followed by annealing. So-obtained samples exhibited integrated characteristics and advantages including porous nanosheets structure, oxygen vacancy , and pseudocapacitance Pseudo-capacitance. The splendid electrochemical properties of Co 3 O 4 electrodes are inseparable from these features providing synergistic effect. During insertion and extraction of lithium ion , porous nanosheets structure not only assisted in buffering volume changes, but also benefitted the transportation of electron/ion. Furthermore, abundant oxygen vacancies improved internal conductivity and promoted migration of lithium ion via regulating surface electronic structure. The pseudocapacitance behavior was instrumental in electrochemical kinetics. Consequently, the resulting nanosized Co 3 O 4 delivered fine discharge specific capacity (1502.5 mAh g −1 ) after 100 cycles at 200 mA g −1 accompanied by the superior capacity retention rate (97.8%). Discharge specific capacity (1093.5 mAh g −1 ) higher than that of graphite, was recorded even at a current density of 2 A g −1 . The results indicate that the as-obtained MNS-CoO 1.0M with excellent properties may act as promising alternative candidates for lithium storage materials.