Three-dimensional (3D) multifunctional carbon nanofibers (CNFs) are promising electrode materials of electrochemical energy storage devices for their unique interconnect structures. Here, we prepared interconnected carbon network decorated with Co3O4 nanoparticles by a facile soak-adsorption strategy. Among them, bacterial cellulose (BC) with inherent interconnect structures was used as carbon precursor. The adsorbed organophosphorus pesticides can introduce new functional groups on the surface of BC and create loose structure for fabricating a loose 3D CNFs skeleton. The absorbed cobalt salt transformed into Co3O4 nanoparticles which anchored on the CNF skeleton to obtain CNFs/Co3O4 composites. This strategy combines interconnected CNFs and uniformly distributed Co3O4 nanoparticles which provide large specific surface area, fast electron transport, well mechanical stability and high electrochemical activity. The CNFs/Co3O4 electrode exhibits a high specific capacitance (785 F g(-1) at 0.5 A g(-1)), superior rate performance (capacity remained 57% from 0.5 to 20 A g(-1)) and good cycling stability (over 93.0% capacity retained after 5000 cycles). Furthermore, the assembled asymmetric device CNFs/Co3O4//activated carbon (AC) possesses a high energy density of 13 Wh kg(-1) at the power density of 257 W kg(-1) and the performance still retains 85.9% of initial capacity after 10,000 cycles.