fig3
From: Tailoring hard carbon interfaces in carbonate-based electrolytes for sodium-ion hybrid capacitors
Figure 3. Electrochemical impedance and surface characterization of HC and HC125@ Co3O4. EIS plots at different temperatures of (A) HC and (B) HC125@Co3O4, and (C) the corresponding equivalent circuits. Arrhenius fitted lines for (D) RSEI and (E) Rct of HC and HC125@Co3O4. (F) Raman fitted plots of NaPF6, HC, Co3O4, HC125@Co3O4. XPS spectra of (G) F1s, (H) O1s and (I) Na1s for HC and HC125@Co3O4 in sodium intercalated state after five cycles.
