Figure 4

(a) AC impedance (inserting the fitted equivalent circuit) of graphite and FLG at the third cycle; (b) The relationship lines between Z′ vs. ω−1/2 in the low frequency region of graphite and FLG; (c) Charge-discharge differential capacity profiles of graphite at 0–3.5 V. (○) 0.1 C and (Δ) 5 C; (d) Charge-discharge differential capacity profiles of FLG at 0–3.5 V. (○) 0.1 C and (Δ) 5 C.