Three novel coordination complexes [Ni(H(2)L1)(DMF)] (Complex 1), [Ca(H(2)L2)(DMF)] (Complex 2), and [Mg(H(2)L2)] (Complex 3) have been synthesized hydrothermally using naphthalene diimide (NDI) ligands. Additionally, these complexes have been studied by single-crystal XRD, IR spectroscopy, TGA analysis, UV-visible spectroscopy, and Hirschfeld surface analysis. Complexes 1 and 2 are 2D polymers of coordination, whereas complex 3 is a 3D coordination framework. The electrochemical properties of the three complexes are determined using cyclic voltammetry (CV) and galvanostatic charge-discharge (GCD) analysis, and their suitability as supercapacitor electrode materials is determined by fabricating working electrodes in 0.5 M TBAPF(6) electrolytes in a three-electrode cell. The capacitances of the three complexes are gravimetric 214 Fg(-1), 141 Fg(-1), and 127 Fg(-1) at 1 Ag-1, respectively, with a voltage window of - 2.5 to 1.0 V and outstanding stability up to 6000 cycles with retentions of around 80%, 78%, and 77%, respectively. We assembled a symmetric device of complex 1 only (because complex 1 has a higher specific capacitance than the other two complexes) that exhibited remarkable electrochemical performance, with a high specific capacitance of 102 Fg(-1) at 0.5 Ag-1 and an excellent energy density of 28 Whkg(-1). Additionally, the symmetric device demonstrated excellent cyclic stability over 5000 charge-discharge cycles at 8 Ag-1 with capacitive retention of 98%. Moreover, DFT study has been carried out to support the results. The results indicate that the three coordination complexes with superior electrochemical characteristics have the potential to operate as capacitors.