Figure 7.

Quantitative capacitive storage analysis and diffusion kinetics of sodium ions in hybrid sponge electrodes: a) CV curves of CNT/CoSe₂/C at various scan rates. b) The relationship between logarithm scan rates and logarithm peak current for all corresponding peaks. c) The contribution of capacitive capacities in percentage at different scan rates. d) Pseudocapacitive contribution (shaded region) in CV curve of CNT/CoSe₂/C at 0.3 mV s⁻¹. e) EIS spectra and f) graph of Z _re with ω^−1/2 in the low frequency range of CNT/CoSe₂ and CNT/CoSe₂/C anodes after 30 cycles.