Author(s): M. Reina, A. Scalia, G. Auxilia, M. Fontana, F. Bella, S. Ferrero, A. Lamberti
Published in: Advanced Sustainable Systems, 2022, ISSN 2366-7486
Publisher: Wiley-VCH GmbH
DOI: 10.1002/adsu.202100228
Abstract: Laser-induced graphene (LIG) is under the spotlight as a promising material for flexible supercapacitors due to its simple processing and flexibility. However, the poor conductivity and the reduced surface area have prompted research to improve its performance, traditionally introducing a pseudocapacitive behavior. Herein an effective yet easy way is presented to dramatically improve the electric double layer capacitance of LIG electrodes for supercapacitor-related applications without the occurrence of redox reactions. The strategy simply relies on the exploitation of an LIG network to trap and interconnect activated carbon (AC) particles. In order to optimize the infiltration of AC into LIG porosities, several strategies are tested, both varying the surface wettability of LIG and acting on the impregnation approach. Overall, the best compromise results in the combination of LIG N-doping by nitric acid incubation with vacuum-assisted infiltration of an AC-slurry, allowing a two-order of magnitude improvement in the specific capacitance up to 20 mF cm−2 in device configuration.
Author(s): P
. Zaccagnini, C. Ballin, M. Fontana, M. Parmeggiani, S. Bianco, A. Pedico, S. Ferrero, A. Lamberti
Published in: Advanced Materials Interfaces, 8, 2021, Page(s) 2101046, ISSN 2366-7486
Publisher: Wiley-VCH GmbH
DOI: 10.1002/admi.202101046
Abstract:
Laser graphenization of polymeric surfaces has emerged as one of the most promising technologies to fabricate flexible electrodes. Unfortunately, despite the large number of materials suitable for laser-induced graphene (LIG) fabrication, there is a lack of stretchable polymers, hindering the full exploitation of LIG for flexible electronics. Herein, the laser graphenization of polydimethylsiloxane (PDMS), the most exploited elastomeric substrate for flexible electronic device fabrication, is proposed for the first time. The low carbon content and the absence of aromatic structures strongly limit the graphenization process resulting in limited conduction properties. Nevertheless, by adding triethylene glycol (TEG) as carbon source into the PDMS matrix, it is possible to improve the graphenization and to reduce the sheet resistance of the written LIG by two orders of magnitude down to 130 ohm sq−1. The PDMS-TEG material becomes a suitable candidate for flexible microsupercapacitor fabrication with specific capacitance values as high as 287 µF cm−2 and energy and power density approaching LIG-based supercapacitors fabricated onto traditional polyimide substrates.
Author(s): A. Chiappone
, A. Pedico, S. Porcu, C. F. Pirri, A. Lamberti, I. Roppolo
Published in: Polymers
, 2022, 14(23), 5265, ISSN
2073-4360
Publisher: MDPI
DOI:
10.3390/polym14235265
Abstract:
Porous organic polymers are versatile platforms, easily adaptable to a wide range of applications, from air filtering to energy devices. Their fabrication via vat photopolymerization enables them to control the geometry on a multiscale level, obtaining hierarchical porosity with enhanced surface-to-volume ratio. In this work, a photocurable ink based on 1,6 Hexanediol diacrylate and containing a high internal phase emulsion (HIPE) is presented, employing PLURONIC F-127 as a surfactant to generate stable micelles. Different parameters were studied to assess the effects on the morphology of the pores, the printability and the mechanical properties. The tests performed demonstrates that only water-in-oil emulsions were suitable for 3D printing. Afterwards, 3D complex porous objects were printed with a Digital Light Processing (DLP) system. Structures with large, interconnected, homogeneous porosity were fabricated with high printing precision (300 µm) and shape fidelity, due to the addition of a Radical Scavenger and a UV Absorber that improved the 3D printing process. The formulations were then used to build scaffolds with complex architecture to test its application as a filter for CO2 absorption and trapping from environmental air. This was obtained by surface decoration with NaOH nanoparticles. Depending on the surface coverage, tested specimens demonstrated long-lasting absorption efficiency.
Author(s): F. Raffone
, A. Lamberti, G. Cicero
Published in:
Electrochimica Acta 2023, 458, 142344, ISSN
0013-4686
Publisher: Elsevier
DOI:
10.1016/j.electacta.2023.142344
Abstract:
Ionic liquids (ILs) have been extensively employed in many applications involving interfaces with carbon-based electrodes, such as energy storage devices (batteries or supercapacitors) or electrocatalytic devices, where the way each ion of the IL interacts with the electrode has a strong impact on the overall performance of the device. For instance, the amount of potential difference between the electrode and the bulk of the IL is highly sensitive to the IL composition and it is directly related to the device capacitance. The selection of the most suited pair of ions often proceeds by time-consuming and costly trial-and-error approaches. It is necessary to understand the atomistic features of the interface to determine the effect of each ion on the potential drop. By classical molecular dynamics simulations, we show that it is possible to quickly infer the interface potential arising at the carbon electrode by carefully inspecting the molecular structure of the IL. The ion orientation at the interface is, in fact, determined by the distribution of charges within the molecules. Depending on where charges are located, ions can either lie flat or perpendicular to the interface to minimize the surface energy. The interface potential is found to be mainly determined by ion–ion interactions dictating the interface energy minimization process, whereas ion–electrode interactions are found to enforce higher ordering and charge layers stacking but not to induce selective adsorption of an ion over the other.
Author(s): D. Molino, A. Pedico, P. Zaccagnini, S. Bocchini, A. Lamberti
Published in:
Electrochimica Acta 2023, 468, 143143, ISSN
0013-4686
Publisher: Elsevier
DOI:
10.1016/j.electacta.2023.143143
Abstract:
In this work we report a green procedure for the infiltration of a SPEEK solution into a porous carbon electrode resulting in a thin-film cation exchange membrane. The electrodes have been investigated by a morphological point of view, showing the formation of a thin coating infiltrated into the porous carbonaceous matrix, while mechanical peeling of a tape demonstrated the adhesion of the proposed layer. The fabricated electrodes have been analyzed by electrochemical measurement. The 3-electrode cyclic voltammetry measurements allowed to verify the voltage window resulting in an improved negative potential, while the electrochemical impedance spectroscopy showed a reduction of the electrical resistance. The SPEEK electrode was used in a supercapacitor and deeply characterized by electrochemical analysis. The reported findings demonstrate for the first time the possibility to exploit a cation exchange material in thin film configuration for supercapacitor application with improved performance of the device and exclusively involving the use of nontoxic reagents.
Author(s): M. Reina, M. Serrapede, P. Zaccagnini, A. Pedico, M. Castellino, S. Bianco, T. Ouisse, H. Pazniak, J. Gonzalez-Julian, A. Lamberti
Published in:
Electrochimica Acta 2023,
468, 143163
Publisher: Elsevier
DOI:
10.1016/j.electacta.2023.143163
Abstract:
During the last years, Internet of Things has become a prominent topic of technical, social, and economic importance. One of the main consequences is the high demand for energy and power density from small energy storage devices. In this field the laser induced graphene (LIG) has become a promising material to produce flexible micro-supercapacitors. The issue with this material is that the performances are strongly restrained by its limited surface area and the relatively low conductivity. In this work we improve the performance of a LIG supercapacitor by decorating its surface through electrophoresis: one electrode will be decorated with metal nitrides and metal carbides (MXenes), the other with manganese oxide. These two materials have appreciable conductivity and pseudocapacitance. Electrochemical measurements have been carried out on the two electrodes separately. After a charge balancing, the device has been sealed in pouch and tested.
Author(s): P. Zaccagnini, Y. Tien, L. Baudino, A. Pedico. S. Bianco, A. Lamberti
Published in:
Advanced Materials Technology 2023, 8 (23), 2300833
Publisher: Wiley
DOI:
10.1002/admt.202300833
Abstract:
Microsupercapacitors (µSCs) have received a lot of interest for their possible use in miniaturized electronics and in the field of the Internet of Things (IoT) to power distributed sensors. µSCs fill the gap between batteries and traditional capacitors, providing high power densities and acceptable energy densities to fulfill onboard power supply requirements, coupled with quick charge/discharge rates and extended lifetime. Charge balancing of µSCs is not a standard practice, although the optimization of electrodes can provide beneficial effects on the electrochemical performance and stability of the device. In this work, a charge-balanced double-layer µSC based on laser-induced graphene (LIG) with [PYR14][TFSI] as an ionic liquid electrolyte is presented for the first time. The optimized device shows an improvement in terms of the increased lifetime of a factor of four and its energy efficiency is raised above 80%.
Author(s): G. Mogli,
M. Reina, A. Chiappone, A. Lamberti, F.C. Pirri. I. Roppolo, S. Stassi
Published in:
Advanced Functional Materials 2023, 34 (7), 202307133
Publisher: Wiley
DOI:
10.1016/j.electacta.2023.143163
Abstract:
Self-healing ionic conductive hydrogels have shown significant potential in applications like wearable electronics, soft robotics, and prosthetics because of their high strain sensitivity and mechanical and electrical recovery after damage. Despite the enormous interest in these materials, conventional fabrication techniques hamper their use in advanced devices since only limited geometries can be obtained, preventing proper conformability to the complexity of human or robotic bodies. Here, a photocurable hydrogel with excellent sensitivity to mechanical deformations based on a semi-interpenetrating polymeric network is reported, which holds remarkable mechanical properties (ultimate tensile strain of 550%) and spontaneous self-healing capabilities, with complete recovery of its strain sensitivity after damages. Furthermore, the developed material can be processed by digital light processing 3D printing technology to fabricate complex-shaped strain sensors, increasing mechanical stress sensitivity with respect to simple sensor geometries, reaching an exceptional pressure detection limit below 1 Pa. Additionally, the hydrogel is used as an electrolyte in the fabrication of a laser-induced graphene-based supercapacitor, then incorporated into a 3D-printed sensor to create a self-powered, fully integrated device. These findings demonstrate that by using 3D printing, it is possible to produce multifunctional, self-powered sensors, appropriately shaped depending on the various applications, without the use of bulky batteries.
