Fig. 3

Electrochemical performance of a blank cell and the cells assembled by Li foils with various interfacial layers. a Electrochemical impedance spectra of various cells (inset in Fig. 2a: equivalent circuit for fitting the impedance results). Frequency: 0.1 Hz–1 MHz, perturbation amplitude 5 mV, measured at 0% state of charge (SOC). b Comparison of R_SEI fitting results of all cells. c, d Comparison of the cyclability of a symmetric cell assembled by blank Li foils (red) and Li foils with interfacial layers of graphene (light blue), electrospun fiber (black), ZnO/CNT (dark yellow), and CNT (blue), respectively, at current densities of c 1 and d 5 mA cm⁻² with a deposition/dissolution capacity of both 1 mAh cm⁻² for c 520 and d 220 cycles