Fig. 6. GCD at different current densities for (a) Co-PYDC MOF (b) Cu-PYDC MOF (c) comparison of GCD for Co-PYDC and Cu-PYDC MOFs at a current density of 0.7 A g⁻¹ (d) specific capacity comparison for Co-PYDC and Cu-PYDC MOFs w.r.t. current densities.