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Multiwalled carbon nanotubes have been synthesized by floating reactant method in a vertical tubular reactor. An internal short approach process was developed to achieve the pre-lithiated multiwalled carbon nanotube MWCNTs/graphite composite anodes. Lithium-ion capacitors (LICs) were composed of a pre-lithiated multiwalled carbon nanotubes/graphite composite anode and an activated carbon (AC) cathode. The electrochemical performance of LICs with different MWCNTs content was investigated through galvanostatic charge/discharge and electrochemical impedance. The results show that the charge-discharge performance of LICs was greatly improved with the addition of MWCNTs in anodes. LIC25 (25 wt% MWCNTs) was found to achieve the optimal electrochemical performance. The LIC25 hold a specific capacitance of 58.2 F/g at the current density of 100 mA/g. The maximum energy density and power density were up to 96 Wh/kg and 10.1 kW/kg, respectively, in the current range of 100~8000 mA/g. The continuous galvanostatic charge-discharge cycling tests revealed that the LIC25 maintained excellent capacity retention of 86% after 3000 cycles. [ABSTRACT FROM AUTHOR]

Si-based anodes are promising to be used in next-generation lithium ion batteries (LIBs), yet limited by low electrical conductivity and pulverization during cycling. The challenge is the simultaneous improvement of electrical conductivity and mechanical stability of the anodes under practical significance. Here, we constructed a ternary conductive 3D network based on hydroxyl-functionalized whisker-like carbon nanofibers (BH). We demonstrate that the hydrogen bond formed at the interactions between SiO x and the ternary conductive network can not only enhance electrode conductivity for the improved capacities and rate performance, but also increase interfacial adhesion strength for good structural stability. The ternary conductive 3D network constructed by BH, Super P, and SWCNTs at the optimal mass ratio of 2.95:7:0.05 enables the SiO x @C/graphite anode (10:90) a high initial discharge specific capacity (565 mAh g−1 at 0.1 C), high rate performance (320.1 mAh g−1 at 0.1 C), and outstanding cycling performance (381.9 mAh g−1 after 100 cycles at 0.2 C). Even the neat SiO x @C electrode with the optimized ternary conductive network delivers stable capacities of 1753.5 mAh g−1 at 0.5 C and 622.5 mAh g−1 at 10 C. The delicate design of 3D conductive networks in this work demonstrates great potential for the application of Si-based anodes in commercial LIBs with high energy densities. • WCNFs were collaboratively prepared through CVD and graphitization treatment. • Enhanced capacities and superior rate performance were attained through the integration of BH, Super P, and SWCNTs. • Ternary conductive agent can increase interfacial adhesion strength for good structural stability. • Suitable framework can buffer the volume expansion of SiO x and inhibit the pulverization during cycling process. [ABSTRACT FROM AUTHOR]