Study On Hybrid Supercapacitors Using Pre-lithiated Carbon-Based As Negative Electrode

Multiwallled carbon nanotubes?MWCNTs?were synthesized via chemical vapor deposition?CVD?and fluorinated multiwallled carbon nanotubes?CF_X?were synthesized plasma method.The electrochemical performance of hybrid supercapacitors?HSC?was investigated by using pre-lithiated carbon-based material as anode and activated carbon?AC?as cathode.The electrode materials were analyzed by scanning electron microscope?SEM?,transmission electron microscope?TEM?,x-ray diffractomer?XRD?,x-ray photoelectron spectrometer?XPS?,raman spectrometer?Raman?,thermal gravimetric analyzer?TGA?and specific surface and void ratio tester?BET?.The electrochemical performance of hybrid supercapacitors was tested by galvanostatic charge/discharge?GCD?and electrochemical impedance spectroscopy?EIS?.The main research results are as follows.The pole piece of pre-lithiated graphite as electrode from preparation of internal short method,The electrochemical performance of hybrid supercapacitors was investigated by using pre-lithiated graphite as anode and activated carbon?AC?as cathode.The experimental tests indicated that the internal short method can eliminate part of the inherent irreversible capacity of graphite and greatly improve the electrochemical performance of hybrid supercapacitors.The capacitors of pre-lithiated graphite as electrode achieved a specific capacitance of 40.34 F/g?0.05 A/g?and maximum energy density and power density reached 64.62 Wh/kg?0.05 A/g?and4028.42 W/kg?3 A/g?respectively in the current range of 0.05³ A/g.The continuous galvanostatic charge-discharge cycling tests revealed that the hybrid supercapacitors maintained capacitance retention of 73.3%after 3000 cycles.The hybrid supercapacitors showed a good application prospects.The electrochemical performance of hybrid supercapacitors was investigated by using stabilized lithium metal powder/multi-walled carbon nanotubes composite as anode and activated carbon?AC?as cathode.The experimental tests indicated that the addition of stabilized lithium metal powder can eliminate majority of the inherent irreversible capacity of carbon nanotubes and greatly improve the electrochemical performance of hybrid supercapacitors.The hybrid supercapacitors achieved a specific capacitance of 85.18 F/g at the current density of 0.05 A/g.The maximum energy density and power density reached 140.4 Wh/kg and 5.25 KW/kg respectively in the current range of 0.05⁴ A/g.The continuous galvanostatic charge-discharge cycling tests revealed that the hybrid supercapacitors maintained capacitance retention of 82%after 3000 cycles.The hybrid supercapacitors showed an excellent cycle performance with high energy and power density.The electrochemical performance of hybrid supercapacitors was investigated by using stabilized lithium metal powder/fluorinated multi-walled carbon nanotubes composite as anode and activated carbon?AC?as cathode.The experimental tests indicated that pole piece of pre-lithiated fluorinated multi-walled carbon nanotubes as electrode from preparation of SLMP,that product formed by the reaction can be stably present on the surface of the electrode,and can effectively prevent the corrosion of the organic electrolyte on the surface of the electrode and prevent the formation of dendrites of lithium.The hybrid supercapacitors achieved a specific capacitance of 135.9 F/g at the current density of 0.05 A/g with pre-lithiated CF_0.59 as electrode.The maximum power density and energy density reached 6454.8 W/kg and172.2 Wh/kg respectively in the current range of 0.05⁴ A/g.The continuous galvanostatic charge-discharge cycling tests revealed that the hybrid capacitors maintained capacitance retention of 92.2%and Coulomb efficiency of 99.1%after3000 cycles.The hybrid supercapacitors showed an excellent cycle performance with high energy and power density.