The GCD curves in Supplementary Fig. further confirm the well-matched mass on both electrodes as the isosceles triangle-shaped profiles are maintained even with an 80-fold increase of the current density. Then, the rate performance is calculated based on these curves where 33.7% of the capacitance is maintained with a larger increase of the current density. Supplementary Fig. and Supplementary Fig. show that the symmetry of galvanostatic charge/discharge is maintained throughout the high current applications with very small ohmic loss indicated by the profile of NFLF negative electrode at fully charge state. Importantly, the two-electrode current-voltage curve in Supplementary Fig.