Carbon-based composite materials for supercapacitor electrodes: a review

International audienc

Nano-encapsulation: overcoming conductivity limitations by growing MOF nanoparticles in meso-porous carbon enables high electrocatalytic performance

MOFs uniquely combine metal-atom centers and developed organic-based structures. Both features are attractive for catalysis. However, their isolating nature prevents them from effective use in electrocatalysis processes. Modifying the chemical structure to gain electric conductivity often harms its natural advantages. In this study, Borenstein et al. present a new approach to overcoming the non-conductivity of MOF b growing MOF nanoparticles in a conductive carbon host. The host’s porosity controls the MOF nanoparticles’ size and their electric properties while preserving their structure. As a result, the composition efficiently electro-catalyzes carbon dioxide into formic acid at low overpotentials

Roll-to-Roll Functionalization of Polyolefin Separators for High-Performance Lithium-Ion Batteries

Modified polyolefin separators fabricated via a roll-to-roll system exhibit markedly improved compatibility with lithium ion battery electrolytes. Zwitterionic molecules containing a perfluorophenyl azide functional group were synthesized and covalently bound to the surface of commercial polyolefin separators via UV-activated photochemistry. A roll-to-roll prototype system was constructed allowing for the functionalization of large areas of separator under ambient conditions at low cost. Lithium-ion battery cells containing the modified separators exhibit superior electrochemical performance using a common commercial electrolyte. The modified separators, both monolayer PE and trilayer PP/PE/PP, are wetted instantly upon contact with liquid electrolytes lacking linear carbonates. These electrolytes have been designed for use in batteries with advanced thermal stability properties and/or higher voltage windows, which have previously been hindered by incompatibility with commercial trilayer polyolefin separators. This scalable modification technique is able to meet the rapidly growing demand for low-cost, high-performance separators for safer lithium-ion batteries

Activated Carbon Modified with Carbon Nanodots as Novel Electrode Material for Supercapacitors

The main goal of this work was to modify activated carbon (AC) with carbon nanodots (C-dots) and to explore the modified composites as electrode materials for supercapacitors. C-dots were synthesized by sonication of polyethylene glycol followed by sonochemical modification of AC matrices with the preprepared C-dots. Sonication introduces the C-dots into the pores of the AC. The effect of the introduction of the C-dots into the AC and their incorporation into the pores was studied. The porosity of the AC/C-dots and the AC reference materials was explored, as well as the impact of the C-dot loading on the performance of the electrodes comprising these AC/C-dots. It was found that the AC/C-dot electrodes demonstrate a specific capacitance of 0.185 F/cm² (per specific electrode area), three times higher than the capacitance of unmodified AC electrodes per specific electrode’s area. It was established that the new electrode’s material, namely, AC/C-dots, exhibits very stable electrochemical behavior. Many thousands of cycles could be demonstrated with stable capacity and a Coulombic efficiency of around 100%

Three-step management of a newborn with a giant, highly vascularized, cervical teratoma: a case report

Abstract Background A giant congenital cervical teratoma is often highly vascularized; thus, in addition to a life-threatening airway occlusion at birth it comprises a high risk for significant and lethal blood loss during resection. In the case presented, an endovascular embolization of the carotid artery that supplied a giant congenital cervical teratoma was done as part of a three-stage treatment soon after birth and contributed to an overall good outcome. Embolization in cases of cervical teratomas was not described previously. Case presentation We present a case of a preterm newborn from a Sephardic jewish origin with a giant, highly vascularized, congenital cervical teratoma that was managed successfully in three stages: (1) delivery by an ex utero intrapartum treatment procedure after extensive preoperative planning and followed by tracheostomy, (2) endovascular embolization of the carotid artery that supplied the tumor in order to decrease blood loss during resection, and (3) complete surgical resection. The parents were involved in all the ethical and medical decisions, starting just after the cervical mass was diagnosed prenatally. Conclusion The management of giant congenital cervical teratoma is often challenging from both a medical and ethical prospective. Meticulous perinatal planning and parents’ involvement is crucial. Endovascular embolization of the tumor feeding vessels can significantly improve the resection outcome and overall prognosis