<p>In order to reduce climate change rate, sustainable energy sources have emerged as a promising solution. Nevertheless, such energy sources require the use of energy storage systems to match optimal performance. Within this context, the design and synthesis of materials, which can provide enhanced energy storage, stand as a major research field. Herein, we established an eco-friendly method to synthesize a coordination polymer (CP) based on benzene-1,4-diboronic acid (BDBA) and Co(II) atoms, entitled Co-BDBA, using only water in the whole synthetic process. Co-BDBA is a crystalline material comprising a mesoporous structure with specific surface area and a mean pore size of 104.9 m²&#xa0;g⁻¹ and 3.4&#xa0;nm, respectively. Remarkably, Co-BDBA features enhanced electrical properties, compared to other reported CPs. Specifically, arguably due to a better orbital overlap in the coordinate bonds, Co-BDBA exhibits a band gap of 3.41&#xa0;eV. Furthermore, Co-BDBA might transport charge carriers by a band-like mechanism. As a result of the enhanced electrical properties, Co-BDBA shows high electrochemical reversibility with a specific capacitance of 345 F g⁻¹ at 1 A g⁻¹ and superior capacitance retention of 109.7% after 2000 galvanostatic charge–discharge cycles. The voltammograms and the galvanostatic charge–discharge profiles indicate a pseudocapacitive behavior, where the energy storage kinetics is controlled by surface processes, <i>i.e.</i>, a capacitive-controlled energy storage kinetics, contrary to the majority of coordination polymers previously reported, which, as best of our knowledge, storage kinetics is diffusion-controlled. Finally, capacitive-controlled energy storage kinetics was also confirmed by electrochemical impedance spectroscopy experiments.</p> Graphical abstract <p></p>