Synthesis and performances of biomass carbon@Li(Ni0.6Co0.4)O2 micron-tube as electrode material in aqueous lithium-ion hybrid supercapacitors

In this paper, biomass carbon@Li(Ni 0.6 Co 0.4 )O 2 (BC@LNCO) micron-tube is successfully synthesized via a bio-templating method as cathodic material for lithium-ion hybrid supercapacitors. Cobalt nickel subcarbonates nanowires arrays are homogeneously grown on bagasse substrate via a unique synthesis strategy using a toluene-water interface reaction process, which subsequently transform as BC@LNCO micron-tube after lithiation process. The distinctive biomass fibre structure of bagasse biomass carbon leads to a significant enhancement in active sites in the BC@LNCO composite, which facilitates lithium-ion diffusion and enhances the contact area between the electrode and electrolyte. So, the prepared BC@LNCO electrode demonstrates improved electrical performances with a high specific capacitance of 921 F g −1 at 1 A g −1 and a good rate performance with 72 % retention at 10 A g −1 . In addition, the lithium-ion hybrid supercapacitor is fabricated with BC@LNCO and activated carbon (AC) as positive and negative electrodes, respectively. The BC@LNCO//AC device demonstrates a good energy density of 56.25 Wh kg −1 at 818.4 W kg −1 , and maintains 25.06 Wh kg −1 when the power density is up to 8143.42 W kg −1 , indicating that the prepared BC@LNCO composite can be a promising candidate as electrode material for Li-ion hybrid supercapacitor.