Sea Urchin-Like MnO₂/Biomass Carbon Composite Electrode Material for High-Performance Supercapacitors

Figure 4

CV curves of BC and MnO₂/BC at 20 mV·s⁻¹ (a); CV curves of two whole cells at 20 mV·s⁻¹ (b); the magnification plot of the two full cells (c); the EIS plot of the asymmetric supercapacitor constructed (d); Ragone (E-P) curve (e); long-cycle curve (f); luminance photos of light-emitting diodes at different times (g); three 2.0 V asymmetric supercapacitors were connected in series and used to light up a yellow electrochemical light-emitting device with RUB as the light-emitting active layer (h).

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