Procyanidins, a class of substances widely distributed in nature, have attracted the attention of the scientific community due to their bioactive properties, especially with regard to human health. This review is based on an extensive examination of peer-reviewed literature, patents, and clinical trial reports published between 2005 and 2025. From an initial pool of more than 300 documents, 283 studies were selected according to criteria of scientific rigor, methodological clarity, and relevance to the research objectives. A literature search was performed using PubMed, PubChem, Google Scholar, Scopus and ResearchGate employing keywords such as Procyanidins, chemical structure, extraction, and health effects. This article provides a comprehensive overview of current methods for obtaining these compounds, which include both natural sources and synthetic approaches. It provides a concise summary of the molecular structure of procyanidins and emphasizes the importance of understanding their conformational features for predicting biological activity. The challenges of establishing correlations between the structural features of procyanidins and their properties are described. In addition, this article explores the many potential applications of these compounds, spanning both biochemistry and the field of design and synthesis of novel materials. This review provides a comprehensive evaluation of Procyanidins, focusing on their geometrical conformation analysis through advanced NMR spectroscopy techniques including homonuclear correlation (COSY, TOCSY), heteronuclear one-bond (HSQC, HMQC), multiple-bond (HMBC) experiments, and through-space correlation (NOESY) in conjunction with various extraction methodologies.

Choline bromide (ChBr) has been less explored as an electrolyte material. This work demonstrates the promising potential of ChBr as a novel aqueous electrolyte for hybrid supercapacitors. At its optimized concentration of 3.5 M, ChBr solution exhibits a maximum conductivity of 79.56 mS cm⁻¹ at room temperature, along with a viscosity of 3.15 mPas and a density of 1.14 g cm⁻³. A reduction in water activity of the optimized ChBr electrolyte concentration extends the electrochemical stability window (ESW), enabling operation up to 1.9 V for two-electrode cells. When the current densities increase from 0.5 to 5 A g⁻¹, the hybrid supercapacitor based on ChBr electrolyte with the optimized mass ratio of electrodes composed of commercial microporous carbon (Maxsorb) demonstrates impressive specific energy and capacitance retention from 41 to 36 Wh kg⁻¹ and from 330 to 300 F g⁻¹ (per mass of one electrode), respectively. The experimental results obtained from this work demonstrate possibilities for further development and applications of ChBr-based hybrid systems in energy storage devices.

Carbon electrodes for capacitive deionization (CDI) are usually ranked by capacitance measured under conditions different from those of desalination. Six electrodes—a microporous activated carbon from waste coffee grounds, a micro-mesoporous templated carbon from magnesium citrate, their 1:1 mixture, and each with 5 wt% polyaniline (PANI)—were characterized electrochemically in 1 M H₂SO₄ and in the NaCl feed at the CDI cell voltage, and tested in batch-mode CDI at +1.6 V. For the three pristine electrodes, capacitance ranked the initial salt adsorption capacity (SAC) correctly in both electrolytes and by every technique, and their 1:1 mixture showed no synergy under the conditions tested. PANI raised the capacitance by 16–18% in acid, but in the feed its contribution varied between the carbons, was partly irreversible and did not follow the SAC, which fell for the coffee-waste carbon and rose for the templated one. No electrochemical measurement anticipated durability: all electrodes retained 95–100% of their capacitance over 10,000 cycles in acid, whereas the pristine ones lost most of their SAC within 100 CDI cycles, and PANI raised the mean SAC retention of the templated carbon from 12% to 76%. Capacitance is thus a useful first screen for purely capacitive carbons, but not for electrodes with a pseudocapacitive component or for predicting service life.

Porous carbon was prepared by direct carbonization of tri-lithium citrate tetrahydrate at 800 °C, followed by acid leaching and re-annealing. Pyrolysis produced Li₂CO₃ and Li₂O within the carbonizate; their removal left an oxygen-functionalized disordered carbon with an openwork structure of crumpled sheets, a BET area of 342 m² g⁻¹ and micropores near 0.9 nm that supply about 40% of the NLDFT surface area. In a symmetric cell with 6 mol L⁻¹ KOH, the carbon delivered a single-electrode capacitance of 91.5 F g⁻¹ at 0.5 A g⁻¹ and retained 80.2 F g⁻¹ at 5 A g⁻¹, with nearly rectangular voltammograms and coulombic efficiencies of at least 98.9%. In concentrated aqueous lithium bis(trifluoromethanesulfonyl)imide (10 mol kg⁻¹), three symmetric coin cells extended the voltage window to 2.0 V and gave a reproducible capacitance of 57.6 ± 0.2 F g⁻¹ at 0.2 A g⁻¹. In batch capacitive deionization with 10 mmol L⁻¹ NaCl at 1.2 V, the electrodes returned a stable charge of 1.4–1.5 C per cycle over 100 cycles and removed 2.54 ± 0.28 mg g⁻¹ of salt in the first five cycles; the decline in salt adsorption on cycling identifies charge efficiency as the next property to improve.