fig3

Figure 3. Sodium and potassium storage behavior and open-circuit voltage: (A) schematic of Na⁺/K⁺-ion transport during charge/discharge; (B) binding energies versus alkali concentration; (C) corresponding open-circuit voltage profiles; (D) comparison of Na⁺/K⁺ diffusion barriers; (E) comparison of theoretical specific capacities with representative anodes^[54-63].