Fish scale derived nitrogen doped hierarchical porous carbon-a high rate performing anode for lithium ion cell

Performance of nitrogen doped porous carbon, obtained from fish scale, has been investigated as an anode material for lithium ion battery in an ionic liquid (IL) electrolyte containing N-butyl,N,N,N-triethylammonium bis(trifluoromethanesulfonyl) imide (N2224-TFSI) and in conventional medium. The N-doped fish scale hierarchical carbon (FSHC) exhibits large surface area (1980 m2 g−1) with uniform pore distribution. The representative anode material shows steady state reversible capacities of ∼500 and 480 mAh g−1 at a current density of 75 mA g−1 and discharge capacities of ∼224.7 and 232.5 mAh g−1 at 2000 mA g−1 in the IL and organic electrolytes respectively for the investigated 75 cycles. Such performance indicates a coulombic efficiency of ∼90 % coupled with a superior capacity retention of about 80%. Post-mortem of the cell containing N-doped FSHC electrode cycled at high current density shows excellent stability in both electrolytes, as confirmed by Field Emission Scanning Electron Microscopy (FE-SEM) and X-ray diffraction pattern (XRD). The enhanced electrochemical performance of the N-doped FSHC as a high capacity anode for lithium-ion batteries could be mainly attributed to the high specific surface area and hierarchical porous structure.