Fig. 6: Generality of design concept and electrochemical performances of Na-ion full cells.

a The dQ/dV curves of graphite negative electrodes in the electrolyte with different volume fractions of DMM. b The polarization and co-intercalation potential (vs. Na/Na⁺) of graphite negative electrodes in screened electrolyte systems, where D denotes DME, G denotes EGDEE, M denotes DMM, E denotes DEE, and the value is indicated by the corresponding volume fraction. The gray line and the area below it represent the normal polarization potential. c, d The GCD curves of NVP positive electrode (c) and graphite | |NVP full cell (d) at 100 mA g⁻¹ in 1 M NaPF₆ DME and 1 M NaPF₆ D1M2. e Rate performance of graphite | |NVP full cell from 0.05 A g⁻¹ to 2 A g⁻¹. f Cycling performance of graphite | |NVP full cell at 1 A g⁻¹ charge and discharge.