Abbas Karim Ahmed, Abdelwahab Abdalla, Abdel-Samad Hesham S, Abd-El Rehim Sayed Sabet, Hassan Hamdy H
Chemistry Department, Faculty of Science, Ain-Shams University Abassia Cairo 11566 Egypt
Faculty of Science, Galala University Sokhna Suez 43511 Egypt.
Nanoscale Adv. 2023 Sep 20;5(20):5499-5512. doi: 10.1039/d3na00517h. eCollection 2023 Oct 10.
The development of metal-free supercapacitor electrodes with a high energy density is a crucial requirement in the global shift towards sustainable energy sources and industrial pursuit of an optimal supercapacitor. Indeed, from an industrial perspective, time assumes a paramount role in the manufacturing process. A majority of synthesis methods employed for the fabrication of carbon xerogel-based supercapacitor electrodes are characterized by prolonged durations, and result in relatively poor energy and power density. These limitations hinder their practical applications and impede their widespread manufacturing capabilities. In this study, carbon xerogel-based supercapacitor electrodes were made in the shortest time ever reported by making the condition highly acidic with hydrochloric acid (HCl). Furthermore, the investigation of the effect of HCl concentrations (0.1 M, 0.05 M, and 0.01 M) on the morphology and electrochemical behavior of the prepared samples is reported herein. Interestingly, the highest concentration of HCl developed the highest BET surface area, 1032 m g, which enforced the capacitive behavior to deliver a specific capacitance of 402 F g at 1 A g and a capacitance retention of 80.8% at a current density of 2 A g in an electrolyte containing 0.5 M HSO + 0.5 M NaSO. Moreover, an impressive energy density of 45 W h kg at a power density of 18.2 kW kg was achieved. Interestingly, as the HCl concentration increased, the equivalent series resistance decreased to 3.9 W with carbon xerogel 0.1 M HCl (CX0.1). The superior performance of CX0.1 may be attributed to its enlarged BET surface area, pore volume, pore diameter, and smaller particle size. This work provides a facile approach for the large-scale production of metal-free carbon supercapacitor electrodes with improved performance and stability and opens novel horizons to explore the impacts of many types of catalysts during the carbon xerogel preparation.
开发具有高能量密度的无金属超级电容器电极是全球向可持续能源转型以及工业追求最优超级电容器的关键需求。事实上，从工业角度来看，时间在制造过程中起着至关重要的作用。用于制造碳气凝胶基超级电容器电极的大多数合成方法的特点是耗时较长，且导致能量和功率密度相对较低。这些限制阻碍了它们的实际应用，并妨碍了它们的大规模制造能力。在本研究中，通过用盐酸（HCl）使条件呈高酸性，在有史以来报道的最短时间内制备了碳气凝胶基超级电容器电极。此外，本文还报道了HCl浓度（0.1 M、0.05 M和0.01 M）对制备样品的形貌和电化学行为的影响。有趣的是，最高浓度的HCl产生了最高的BET表面积，为1032 m²/g，这增强了电容行为，在含有0.5 M H₂SO₄ + 0.5 M Na₂SO₄的电解质中，在1 A/g时提供了402 F/g的比电容，在2 A/g的电流密度下电容保持率为80.8%。此外，在功率密度为18.2 kW/kg时实现了令人印象深刻的45 W h/kg的能量密度。有趣的是，随着HCl浓度的增加，0.1 M HCl碳气凝胶（CX0.1）的等效串联电阻降至3.9 Ω。CX0.1的优异性能可能归因于其增大的BET表面积、孔体积、孔径和更小的粒径。这项工作为大规模生产性能和稳定性得到改善的无金属碳超级电容器电极提供了一种简便方法，并为探索碳气凝胶制备过程中多种类型催化剂的影响开辟了新的视野。
