Quantum mechanics

Voltage

Composite number

Engineering

Lithium (medication)

Electrochemistry

Pseudocapacitance

Materials science

Cathode

Endocrinology

Carbon fibers

Chemical engineering

Capacitor

Physical chemistry

Polymer

Supercapacitor

Physics

Nanotechnology

Carbon nanotube

Electrospinning

Carbonization

Carbon nanofiber

Composite material

Medicine

Chemistry

Scanning electron microscope

Nanofiber

Electrode

Anode

Electrolyte

Electrical engineering

Electrochimica Acta

The development of high-energy lithium-ion and sodium-ion capacitors (LICs and SICs) is still a challenge due to the kinetics mismatch between the insertion/deinsertion anode and adsorption/desorption cathode. Here, high-level N/P-doped Sn-carbon nanofibers (Sn-NP-CNFs) were fabricated via an electrospinning technique followed by pre-oxidization and carbonization. The N/P-doping increased the defects and carbon interlayer distance to inhibit the precipitation and volume expansion of the Sn and improve the Li/Na-adsorption, resulting in an ultrahigh pseudocapacitance and rate capability of the Sn-NP-CNF. An advanced LIC and SIC were composed of an activated carbon cathode and a Sn-NP-CNF anode. The LIC and SIC displayed ultrahigh energy densities (186.0 Wh kg−1 and 134.6 Wh kg−1) and power densities (20.0 kW kg−1 achieved at 22.2 Wh kg−1) with superior energy retentions (83.7% and 79.8% after 10,000 cycles at 5.0 A g−1).

High-level N/P co-doped Sn-carbon nanofibers with ultrahigh pseudocapacitance for high-energy lithium-ion and sodium-ion capacitors