This page has only limited features, please log in for full access.

Unclaimed
Pier Giorgio Schiavi
Department of Chemistry, Sapienza University of Rome, Piazzale Aldo Moro n.5, 00185 Rome, Italy

Honors and Awards

The user has no records in this section


Career Timeline

The user has no records in this section.


Short Biography

The user biography is not available.
Following
Followers
Co Authors
The list of users this user is following is empty.
Following: 0 users

Feed

Journal article
Published: 15 August 2021 in Energies
Reads 0
Downloads 0

Catalytic electroreduction of carbon dioxide represents a promising technology both to reduce CO2 emissions and to store electrical energy from discontinuous sources. In this work, electrochemical deposition of copper on to a gas-diffusion support was tested as a scalable and versatile nanosynthesis technique for the production of catalytic electrodes for CO2 electroreduction. The effect of deposition current density and additives (DAT, DTAB, PEG) on the catalysts’ structure was evaluated. The selectivity of the synthesized catalysts towards the production of CO was evaluated by analyzing the gaseous products obtained using the catalysts as cathodes in electroreduction tests. Catalyst morphology was deeply influenced by the deposition additives. Copper nanospheres, hemispherical microaggregates of nanowires, and shapeless structures were electrodeposited in the presence of dodecyltrimethylammonium bromide (DTAB), 3,5-diamino-1,2,4-triazole (DAT) and polyethylene glycol (PEG), respectively. The effect of the deposition current density on catalyst morphology was also observed and it was found to be additive-specific. DTAB nanostructured electrodes showed the highest selectivity towards CO production, probably attributable to a higher specific surface area. EDX and XPS analysis disclosed the presence of residual DAT and DTAB uniformly distributed onto the catalysts structure. No significant effects of electrodeposition current density and Cu(I)/Cu(II) ratio on the selectivity towards CO were found. In particular, DTAB and DAT electrodes yielded comparable selectivity, although they were characterized by the highest and lowest Cu(I)/Cu(II) ratio, respectively.

ACS Style

Gianluca Zanellato; Pier Giorgio Schiavi; Robertino Zanoni; Antonio Rubino; Pietro Altimari; Francesca Pagnanelli. Electrodeposited Copper Nanocatalysts for CO2 Electroreduction: Effect of Electrodeposition Conditions on Catalysts’ Morphology and Selectivity. Energies 2021, 14, 5012 .

AMA Style

Gianluca Zanellato, Pier Giorgio Schiavi, Robertino Zanoni, Antonio Rubino, Pietro Altimari, Francesca Pagnanelli. Electrodeposited Copper Nanocatalysts for CO2 Electroreduction: Effect of Electrodeposition Conditions on Catalysts’ Morphology and Selectivity. Energies. 2021; 14 (16):5012.

Chicago/Turabian Style

Gianluca Zanellato; Pier Giorgio Schiavi; Robertino Zanoni; Antonio Rubino; Pietro Altimari; Francesca Pagnanelli. 2021. "Electrodeposited Copper Nanocatalysts for CO2 Electroreduction: Effect of Electrodeposition Conditions on Catalysts’ Morphology and Selectivity." Energies 14, no. 16: 5012.

Journal article
Published: 10 March 2021 in Chemical Engineering Journal
Reads 0
Downloads 0

Despite the efforts devoted to the development of new cathodic materials, cobalt-based lithium-ion batteries (LIBs) remain the first choice for many applications, turning cobalt into a critical raw material. Here, we report a method for the selective recovery of cobalt from mixed LIBs electrode materials. The method relies on the application of a green deep eutectic solvent (DES) and yields an extraction of 90% for cobalt and only 10% for nickel. A solvent extraction procedure was optimized to recover cobalt as cobalt oxalate, which was employed to produce lithium cobalt oxide cathode material. This produced cathode material delivered a discharge capacity of 150 mAh g−1 and a capacity retention between 10 and 100 galvanostatic cycles of 83%. Remarkably, the residual DES solution was reused delivering the same cobalt extraction attained using the fresh DES. Cobalt separation constitutes one of the major bottleneck during LIBs recycling, requiring costly and complex hydrometallurgical operations. The demonstrated selectivity of the implemented leaching method, along with the possibility to reuse the residual DES solution, paves the way to a green recycling alternative allowing for the reintroduction of strategic materials into the LIBs production chain.

ACS Style

Pier Giorgio Schiavi; Pietro Altimari; Mario Branchi; Robertino Zanoni; Giulia Simonetti; Maria Assunta Navarra; Francesca Pagnanelli. Selective recovery of cobalt from mixed lithium ion battery wastes using deep eutectic solvent. Chemical Engineering Journal 2021, 417, 129249 .

AMA Style

Pier Giorgio Schiavi, Pietro Altimari, Mario Branchi, Robertino Zanoni, Giulia Simonetti, Maria Assunta Navarra, Francesca Pagnanelli. Selective recovery of cobalt from mixed lithium ion battery wastes using deep eutectic solvent. Chemical Engineering Journal. 2021; 417 ():129249.

Chicago/Turabian Style

Pier Giorgio Schiavi; Pietro Altimari; Mario Branchi; Robertino Zanoni; Giulia Simonetti; Maria Assunta Navarra; Francesca Pagnanelli. 2021. "Selective recovery of cobalt from mixed lithium ion battery wastes using deep eutectic solvent." Chemical Engineering Journal 417, no. : 129249.

Journal article
Published: 01 November 2020 in Journal of Energy Chemistry
Reads 0
Downloads 0

A novel process is reported which produces an asymmetric supercapacitor through the complete recycling of end-of-life lithium ion batteries. The electrodic powder recovered by industrial scale mechanical treatment of spent batteries was leached and the dissolved metals were precipitated as mixed metals carbonates. Nanowires battery-type positive electrodes were produced by electrodeposition into nanoporous alumina templates from the electrolytic baths prepared by dissolution of the precipitated carbonates. The impact of the different metals contained in the electrodic powder was evaluated by benchmarking the electrochemical performances of the recovered nanowires-based electrodes against electrodes produced by using high-purity salts. Presence of inactive Cu in the nanowires lowered the final capacitance of the electrodes while Ni showed a synergistic effect with cobalt providing a higher capacitance with respect to synthetic Co electrodes. The carbonaceous solid recovered after leaching was in-depth characterized and tested as negative electrode. Both the chemical and electrochemical characterization indicate that the recovered graphite is characterized by the presence of oxygen functionalities introduced by the leaching treatment. This has led to the obtainment of a recovered graphite characterized by an XPS C/O ratio, Raman spectrum and morphology close to literature reports for reduced graphene oxide. The asymmetric supercapacitor assembled using the recovered nanowires-based positive electrodes and graphite as negative electrodes has shown a specific capacitance of 42 F g−1, computed including the whole weight of the positive electrode and recovered graphite, providing a maximum energy density of ~9 Wh kg−1 and a power density of 416 W kg−1 at 2.5 mA cm−2.

ACS Style

Pier Giorgio Schiavi; Pietro Altimari; Robertino Zanoni; Francesca Pagnanelli. Full recycling of spent lithium ion batteries with production of core-shell nanowires//exfoliated graphite asymmetric supercapacitor. Journal of Energy Chemistry 2020, 58, 336 -344.

AMA Style

Pier Giorgio Schiavi, Pietro Altimari, Robertino Zanoni, Francesca Pagnanelli. Full recycling of spent lithium ion batteries with production of core-shell nanowires//exfoliated graphite asymmetric supercapacitor. Journal of Energy Chemistry. 2020; 58 ():336-344.

Chicago/Turabian Style

Pier Giorgio Schiavi; Pietro Altimari; Robertino Zanoni; Francesca Pagnanelli. 2020. "Full recycling of spent lithium ion batteries with production of core-shell nanowires//exfoliated graphite asymmetric supercapacitor." Journal of Energy Chemistry 58, no. : 336-344.

Journal article
Published: 24 October 2020 in Journal of Alloys and Compounds
Reads 0
Downloads 0

An experimental analysis was performed to optimize the structure of Ni–Ni(OH)2/NiO core-shell nanowire electrodes for improving their application in pseudocapacitors. Thickness and composition of the active phase shell were compared after thermal treatments at 40, 70 and 300 °C. A Ni(0) core was found by XPS in the electrode treated at 40 °C, it was still present after a temperature increase to 70 °C but with a lower Ni(OH)2/NiO ratio of the active phase shell, and disappeared after annealing at 300 °C, with a corresponding increase of the charge transfer resistance. The capacitance values increased from 40 to 70 °C and drop to a minimum for the electrode treated at 300 °C. A tailoring of the capacitance of the nanowire electrodes by controlling their length was evaluated. A constant capacitance per nanowires length unit was attained between 5 and 21 μm, indicating that the corresponding mass transfer resistance was negligible over the explored range. These results evidence the relevance to tightly control the thickness and ratio between the Ni(OH)2 and NiO in the nanowires shell and provide a guideline to optimize the capacitance of the electrode by controlling the nanowire length.

ACS Style

Pier Giorgio Schiavi; Pietro Altimari; Flavio Marzolo; Antonio Rubino; Robertino Zanoni; Francesca Pagnanelli. Optimizing the structure of Ni–Ni(OH)2/NiO core-shell nanowire electrodes for application in pseudocapacitors: The influence of metallic core, Ni(OH)2/NiO ratio and nanowire length. Journal of Alloys and Compounds 2020, 856, 157718 .

AMA Style

Pier Giorgio Schiavi, Pietro Altimari, Flavio Marzolo, Antonio Rubino, Robertino Zanoni, Francesca Pagnanelli. Optimizing the structure of Ni–Ni(OH)2/NiO core-shell nanowire electrodes for application in pseudocapacitors: The influence of metallic core, Ni(OH)2/NiO ratio and nanowire length. Journal of Alloys and Compounds. 2020; 856 ():157718.

Chicago/Turabian Style

Pier Giorgio Schiavi; Pietro Altimari; Flavio Marzolo; Antonio Rubino; Robertino Zanoni; Francesca Pagnanelli. 2020. "Optimizing the structure of Ni–Ni(OH)2/NiO core-shell nanowire electrodes for application in pseudocapacitors: The influence of metallic core, Ni(OH)2/NiO ratio and nanowire length." Journal of Alloys and Compounds 856, no. : 157718.

Journal article
Published: 02 September 2020 in Energies
Reads 0
Downloads 0

Li primary batteries are currently treated along with other Li batteries in several big pyro- metallurgical plants in Northern EU countries. Nevertheless, pyro-metallurgical processes do not allow for Mn and Li recycling and present negative environmental impacts, on the other hand hydrometallurgical processing can potentially ensure the integral recovery of all materials in Li primary batteries. In this work, preliminary experimental findings obtained in the LIFE-LIBAT project (LIFE16 ENV/IT/000389) are reported. In this project, end of life Li(0)-MnO2 batteries were cryo-mechanically treated and then the metals were recovered by a hydrometallurgical process. Representative samples of end of life Li(0) batteries were characterized by type and composition. Batteries were stabilized in an N2 bath and then crushed, sieved, and magnetically separated in the SEVal pilot units. Separated fractions (fine fraction, magnetic coarse fraction, and non-magnetic coarse fraction) were chemically characterized for target metal content (Li and Mn). Fractions were first treated for Li extraction and recovery, then the fine fraction was also leached for Mn recovery. Mass balances evidenced a 55% recycling rate and process simulations outlined profitability in the potentiality range in agreement with battery collection fluxes.

ACS Style

Pier Giorgio Schiavi; Ludovica Baldassari; Pietro Altimari; Emanuela Moscardini; Luigi Toro; Francesca Pagnanelli. Process Simulation for Li-MnO2 Primary Battery Recycling: Cryo-Mechanical and Hydrometallurgical Treatments at Pilot Scale. Energies 2020, 13, 4546 .

AMA Style

Pier Giorgio Schiavi, Ludovica Baldassari, Pietro Altimari, Emanuela Moscardini, Luigi Toro, Francesca Pagnanelli. Process Simulation for Li-MnO2 Primary Battery Recycling: Cryo-Mechanical and Hydrometallurgical Treatments at Pilot Scale. Energies. 2020; 13 (17):4546.

Chicago/Turabian Style

Pier Giorgio Schiavi; Ludovica Baldassari; Pietro Altimari; Emanuela Moscardini; Luigi Toro; Francesca Pagnanelli. 2020. "Process Simulation for Li-MnO2 Primary Battery Recycling: Cryo-Mechanical and Hydrometallurgical Treatments at Pilot Scale." Energies 13, no. 17: 4546.

Journal article
Published: 03 August 2020 in Energies
Reads 0
Downloads 0

In this work, an innovative hydrometallurgical recycling route for the recovery of all the materials composing Li-MnO2 primary batteries was proposed. End-of-life batteries were mechanically treated in an innovative pilot plant where a cryogenic crushing was performed. The mechanical treatment allowed for the release of the electrodic powder contained in the batteries with the simultaneous recovery of 44 kg of steel and 18 kg of plastics from 100 kg of batteries. Electrodic powder was employed as the raw material for the synthesis of LiMnPO4 nanoparticles. To obtain the synthesis precursors, selective sequential leaching of Li and Mn was performed. Li was extracted via water washing the electrodic powder and Li2CO3 and a purity of 99% was recovered. The black mass containing Mn oxides was leached using phosphoric acid, which gave a Mn-bearing precursor solution that was directly used for the hydrothermal synthesis of LiMnPO4 nanoparticles. A preliminary materials balance of the process was presented, indicating that the proposed process should be an easy hydrometallurgical route for the recycling of primary lithium batteries. In addition, the simultaneous production of high-value-added products that could be reintroduced into the battery manufacturing chain could ensure the economic feasibility of the process.

ACS Style

Pier Giorgio Schiavi; Flavia Carla Dos Santos Martins Padoan; Pietro Altimari; Francesca Pagnanelli. Cryo-Mechanical Treatment and Hydrometallurgical Process for Recycling Li-MnO2 Primary Batteries with the Direct Production of LiMnPO4 Nanoparticles. Energies 2020, 13, 4004 .

AMA Style

Pier Giorgio Schiavi, Flavia Carla Dos Santos Martins Padoan, Pietro Altimari, Francesca Pagnanelli. Cryo-Mechanical Treatment and Hydrometallurgical Process for Recycling Li-MnO2 Primary Batteries with the Direct Production of LiMnPO4 Nanoparticles. Energies. 2020; 13 (15):4004.

Chicago/Turabian Style

Pier Giorgio Schiavi; Flavia Carla Dos Santos Martins Padoan; Pietro Altimari; Francesca Pagnanelli. 2020. "Cryo-Mechanical Treatment and Hydrometallurgical Process for Recycling Li-MnO2 Primary Batteries with the Direct Production of LiMnPO4 Nanoparticles." Energies 13, no. 15: 4004.

Journal article
Published: 05 March 2020 in The Journal of Physical Chemistry B
Reads 0
Downloads 0

Non-covalent DNA functionalization is one of the most used route for easy dispersion of carbon nanotubes (CNTs) yielding DNA-CNTs complexes with promising applications. Definition of the structure of adsorbed DNA is crucial but the organization of polymer at the carbon interface is far from being understood. In comparison to single-walled nanotubes, not many efforts have been devoted to assess the structure of the adsorbed DNA on multi-walled carbon nanotubes (MWCNTs), where their metallic nature and large size and polydispersity represent serious obstacles for both experimental and theoretical studies. As a contribution to fill this lack in these aspects, we investigated DNA-MWCNT complexes by Dielectric Spectroscopy (DS) which is sensitive to even small changes in the charge distribution at charged interfaces and was largely employed in studying electric and conformational properties of polyelectrolytes, such as DNA, in aqueous solutions and at interfaces. The dielectric relaxation in the MHz range is the signature of DNA adsorption on CNTs and shed light on its conformational properties. A detailed analysis of the conductivity of the DNA-MWCNT suspensions unequivocally proves that DNA is adsorbed in single-stranded conformation, while excess DNA reassociates without interfering with the stability of the complexes.

ACS Style

Franco Tardani; Stefano Sarti; Simona Sennato; Manuela Leo; Patrizia Filetici; Stefano Casciardi; Pier Giorgio Schiavi; Federico Bordi. Experimental Evidence of Single-Stranded DNA Adsorption on Multiwalled Carbon Nanotubes. The Journal of Physical Chemistry B 2020, 124, 2514 -2525.

AMA Style

Franco Tardani, Stefano Sarti, Simona Sennato, Manuela Leo, Patrizia Filetici, Stefano Casciardi, Pier Giorgio Schiavi, Federico Bordi. Experimental Evidence of Single-Stranded DNA Adsorption on Multiwalled Carbon Nanotubes. The Journal of Physical Chemistry B. 2020; 124 (12):2514-2525.

Chicago/Turabian Style

Franco Tardani; Stefano Sarti; Simona Sennato; Manuela Leo; Patrizia Filetici; Stefano Casciardi; Pier Giorgio Schiavi; Federico Bordi. 2020. "Experimental Evidence of Single-Stranded DNA Adsorption on Multiwalled Carbon Nanotubes." The Journal of Physical Chemistry B 124, no. 12: 2514-2525.

Journal article
Published: 30 August 2019 in Journal of Electroanalytical Chemistry
Reads 0
Downloads 0

Electrochemical nucleation and growth of cobalt nanoparticles on aluminium was investigated by potentiostatic electrodeposition from cobalt sulphate solutions buffered with boric acid. At sufficiently low overpotential, the experimental current transients could be fairly reproduced by a mathematical model describing nucleation and growth under mixed kinetic-diffusion control, yielding an estimated number of particles per surface area in agreement with the SEM analysis of the deposits. However, the model gave estimates for the charge-transfer kinetic constant several orders of magnitude lower as compared to the Tafel analysis of cobalt electrodeposition on a previously electrodeposited cobalt film. This deviation can be explained by the inhibition of the direct attachment of metal ions, which can be induced by the adsorption of hydrogen onto cobalt particles and/or the formation of stable nanocluster aggregates. The implemented model failed to reproduce the current transients generated at larger overpotential values. A revision of the implemented mathematical model overcoming this limitation is proposed.

ACS Style

Pietro Altimari; Pier Giorgio Schiavi; Antonio Rubino; Francesca Pagnanelli. Electrodeposition of cobalt nanoparticles: An analysis of the mechanisms behind the deviation from three-dimensional diffusion-control. Journal of Electroanalytical Chemistry 2019, 851, 113413 .

AMA Style

Pietro Altimari, Pier Giorgio Schiavi, Antonio Rubino, Francesca Pagnanelli. Electrodeposition of cobalt nanoparticles: An analysis of the mechanisms behind the deviation from three-dimensional diffusion-control. Journal of Electroanalytical Chemistry. 2019; 851 ():113413.

Chicago/Turabian Style

Pietro Altimari; Pier Giorgio Schiavi; Antonio Rubino; Francesca Pagnanelli. 2019. "Electrodeposition of cobalt nanoparticles: An analysis of the mechanisms behind the deviation from three-dimensional diffusion-control." Journal of Electroanalytical Chemistry 851, no. : 113413.

Conference paper
Published: 27 August 2019 in 15th International Conference on Concentrator Photovoltaic Systems (CPV-15)
Reads 0
Downloads 0

In this work, an electrochemical approach to synthesize Metal-MetalOxide/Hydroxide core-shell nanowires electrodes (NWE) is illustrated. NWE electrodes were obtained by electrodeposition of a targeted metal into the nanopores of nanoporous alumina templates generated by one-step anodization of aluminum. Following metal electrodeposition, the alumina template was selectively etched to obtain an array of free-standing metal nanowires. The imposed electrodeposition conditions allowed directly attaining a core-shell nanostructure, with a metal core covered by a thin metal oxide/hydroxide film. NWE electrodes produced by the proposed synthesis route were tested for the application as electrodes in lithium batteries and supercapacitors. To this purpose, an array of cobalt nanowires (CoNWs) supported by a nanostructured copper current collector was produced by sequential electrodeposition of cobalt and copper, and it was employed as anode in a lithium battery, while a NWE based on Ni-NiO/OH2 (NiNWs) was obtained by nickel electrodeposition and tested as electrode in a supercapacitor. A thorough analysis and characterization of the produced electrodes were performed. The experiments with the lithium cell evidenced the positive effect of metallic core on stability, while the electrochemical characterization of the supercapacitor showed the presence of both NiO and NiOH2 leading, when cycled, to a capacity close to the best literature value.

ACS Style

Pier Giorgio Schiavi; Luca Farina; Antonio Rubino; Pietro Altimari; Maria Assunta Navarra; Robertino Zanoni; Stefania Panero; Francesca Pagnanelli. Electrochemical synthesis of nanowires electrodes and their application in energy storage devices. 15th International Conference on Concentrator Photovoltaic Systems (CPV-15) 2019, 2145, 020012 .

AMA Style

Pier Giorgio Schiavi, Luca Farina, Antonio Rubino, Pietro Altimari, Maria Assunta Navarra, Robertino Zanoni, Stefania Panero, Francesca Pagnanelli. Electrochemical synthesis of nanowires electrodes and their application in energy storage devices. 15th International Conference on Concentrator Photovoltaic Systems (CPV-15). 2019; 2145 (1):020012.

Chicago/Turabian Style

Pier Giorgio Schiavi; Luca Farina; Antonio Rubino; Pietro Altimari; Maria Assunta Navarra; Robertino Zanoni; Stefania Panero; Francesca Pagnanelli. 2019. "Electrochemical synthesis of nanowires electrodes and their application in energy storage devices." 15th International Conference on Concentrator Photovoltaic Systems (CPV-15) 2145, no. 1: 020012.

Conference paper
Published: 27 August 2019 in 15th International Conference on Concentrator Photovoltaic Systems (CPV-15)
Reads 0
Downloads 0

Energy from renewables (solar, photovoltaic, geothermal), is a major challenge for researchers’ efforts in reason of the intermittent nature of these energy sources. Systems like photoelectrochemical (PEC) cells are promising devices that allow the direct conversion of solar energy into electric power and/or chemical fuels. The direct conversion of solar energy in fuels can be achieved using photocatalysts, based on semiconductors like TiO2. In this work TiO2 nanotubes were achieved through “one-step” anodization of titanium, a low cost and accurate method which allowed to control dimensions and morphology of the nanostructured Ti/TiO2 electrodes. Central limit for TiO2 photoconversion efficiency is its wide bandgap (i.e. ~3.2eV), which limits light absorption to the ultraviolet region (3–5% of the solar radiation). Composite Cu2O/TiO2 systems have attracted much attention: Cu2O is a promising semiconductor material (bandgap 2.0-2.6eV), suitable to absorb visible light. Traditionally, Cu2O deposition techniques include the impregnation of TiO2 with a copper salt and subsequent calcination, but offers little control on sizes, shape and deposit’s composition. In this work we developed an electrodeposition method in order to control Cu2O morphology and sizes in the composed Ti/TiO2/Cu2O electrodes.

ACS Style

Antonio Rubino; Pier Giorgio Schiavi; Pietro Altimari; Francesca Pagnanelli. Ti/TiO2/Cu2O electrodes for photocatalytic applications: Synthesis and characterization. 15th International Conference on Concentrator Photovoltaic Systems (CPV-15) 2019, 2145, 020005 .

AMA Style

Antonio Rubino, Pier Giorgio Schiavi, Pietro Altimari, Francesca Pagnanelli. Ti/TiO2/Cu2O electrodes for photocatalytic applications: Synthesis and characterization. 15th International Conference on Concentrator Photovoltaic Systems (CPV-15). 2019; 2145 (1):020005.

Chicago/Turabian Style

Antonio Rubino; Pier Giorgio Schiavi; Pietro Altimari; Francesca Pagnanelli. 2019. "Ti/TiO2/Cu2O electrodes for photocatalytic applications: Synthesis and characterization." 15th International Conference on Concentrator Photovoltaic Systems (CPV-15) 2145, no. 1: 020005.

Journal article
Published: 06 July 2019 in Electrochimica Acta
Reads 0
Downloads 0

A novel process is proposed to produce nanostructured batteries anodes from spent lithium-ion batteries. The electrodic powder recovered by the mechanical treatment of spent batteries was leached and the dissolved metals were precipitated as cobalt carbonates. Two different precipitation routes were separately tested producing cobalt carbonates with different Cu and Fe contents. Nanowire anodes were produced by electrodeposition into nanoporous alumina templates from the electrolytic baths prepared by dissolution of the precipitated carbonates. The electrochemical performances of the produced anodes were evaluated as compared to nanowire anodes produced with the same electrodeposition method but using a synthetic cobalt bath. The application of the carbonates produced by directly precipitating all the leached metals gave nanowires with capacity about halved as compared to the nanowires electrodeposited from the synthetic bath. Selectively removing Cu and Fe prior cobalt carbonate precipitation yielded, in contrast, nanowires with capacity initially larger and then gradually approaching that attained by the nanowire electrodeposited from the synthetic bath. A detailed analysis is presented describing the role of metallic impurities in determining the capacity of the produced nanowires. The impact of the illustrated results for the development of sustainable recycling processes of lithium-ion batteries is discussed.

ACS Style

Pier Giorgio Schiavi; Luca Farina; Robertino Zanoni; Pietro Altimari; Iulia Cojocariu; Antonio Rubino; Maria Assunta Navarra; Stefania Panero; Francesca Pagnanelli. Electrochemical synthesis of nanowire anodes from spent lithium ion batteries. Electrochimica Acta 2019, 319, 481 -489.

AMA Style

Pier Giorgio Schiavi, Luca Farina, Robertino Zanoni, Pietro Altimari, Iulia Cojocariu, Antonio Rubino, Maria Assunta Navarra, Stefania Panero, Francesca Pagnanelli. Electrochemical synthesis of nanowire anodes from spent lithium ion batteries. Electrochimica Acta. 2019; 319 ():481-489.

Chicago/Turabian Style

Pier Giorgio Schiavi; Luca Farina; Robertino Zanoni; Pietro Altimari; Iulia Cojocariu; Antonio Rubino; Maria Assunta Navarra; Stefania Panero; Francesca Pagnanelli. 2019. "Electrochemical synthesis of nanowire anodes from spent lithium ion batteries." Electrochimica Acta 319, no. : 481-489.

Journal article
Published: 14 September 2018 in Electrochimica Acta
Reads 0
Downloads 0

A novel electrochemical method is proposed to synthesize nanostructured cobalt electrodes for lithium-ion batteries (LIBs). An array of cobalt nanowires (CoNWs) supported by a nanostructured copper current collector was obtained by the sequential electrodeposition of cobalt and copper into the nanopores of alumina templates and selective etching of alumina. The illustrated method can be implemented with one-side open alumina templates generated by one-step aluminium anodization, thus excluding the application alumina membranes and their coating by sputter metal deposition. The cobalt electrodeposition conditions allow to directly form Co-CoO core-shell nanowires, with metallic cobalt nanowires covered by a thin cobalt oxide film. The direct electrochemical growth of copper nanowires connected to CoNWs ensured high electronic conductivity and specific surface area of the resulting electrode, leading to a low interfacial impedance when used in lithium cell. This nanostructure and the enhanced lithium diffusion enabled by the nanowires morphology contributed to achieve a specific capacity of 1500 mAhg−1 after 200 cycles at 2 Ag-1, and complete restore of the capacity at 2 Ag-1 after cycling at the ultra-high current density of 450 Ag-1. The faradaic and capacitive contributions to charge storage were estimated by the analysis of cyclic voltammetry experiments carried out at different scan rates. Based on this latter analysis, pseudo-capacitive effects appear to play a pivotal role in determining the total recorded capacity. The advantages of the proposed method to sustain the large scale application of nanowires electrodes in lithium batteries are thoroughly discussed.

ACS Style

Pier Giorgio Schiavi; Luca Farina; Pietro Altimari; Maria Assunta Navarra; Robertino Zanoni; Stefania Panero; Francesca Pagnanelli. A versatile electrochemical method to synthesize Co-CoO core-shell nanowires anodes for lithium ion batteries with superior stability and rate capability. Electrochimica Acta 2018, 290, 347 -355.

AMA Style

Pier Giorgio Schiavi, Luca Farina, Pietro Altimari, Maria Assunta Navarra, Robertino Zanoni, Stefania Panero, Francesca Pagnanelli. A versatile electrochemical method to synthesize Co-CoO core-shell nanowires anodes for lithium ion batteries with superior stability and rate capability. Electrochimica Acta. 2018; 290 ():347-355.

Chicago/Turabian Style

Pier Giorgio Schiavi; Luca Farina; Pietro Altimari; Maria Assunta Navarra; Robertino Zanoni; Stefania Panero; Francesca Pagnanelli. 2018. "A versatile electrochemical method to synthesize Co-CoO core-shell nanowires anodes for lithium ion batteries with superior stability and rate capability." Electrochimica Acta 290, no. : 347-355.

Conference paper
Published: 23 July 2018 in EMERGING TECHNOLOGIES: MICRO TO NANO (ETMN-2017): Proceedings of the 3rd International Conference on Emerging Technologies: Micro to Nano
Reads 0
Downloads 0

In this contribution, two different strategies are discussed to synthesize cobalt nanostructures: direct cobalt electrodeposition on a planar aluminum electrode and cobalt electrodeposition into nanoporous alumina templates generated by aluminum anodization (template electrodeposition). In the direct electrodeposition of cobalt on aluminum, cobalt nanoparticles are formed during the early stage of electrodeposition, which causes the depletion of cobalt ions near the electrode. Water reduction then takes place catalyzed by electrodeposited cobalt nanoparticles, which increases the pH near the electrode and can induce cobalt hydroxide precipitation. By varying the electrode potential and the cobalt ion concentration, the interplay between electrochemical growth of cobalt and water reduction could be controlled to induce transition from cobalt hexagonal nano-platelets to nanostructured films composed of cobalt nanoparticles and cobalt hydroxide nano-flakes. Cobalt nanowires can be synthesized by electrodeposition into nanoporous alumina templates generated by aluminum anodization. This approach typically involves the application of alumina templates produced by a two-step anodization procedure: the alumina nanoporous layer generated by a first anodization is dissolved in a chromic acid solution while a very ordered alumina nanoporous layer is produced by a second anodization stage. In accordance with previous studies, this procedure is fundamental to achieve uniform filling of the nanopores in the subsequent electrodeposition stage. In the present study, uniform filling of the nanoporous alumina generated by one-step anodization could be achieved by the electrodeposition of cobalt nanowires. This result was made possible by the application of a novel pulsed electrodeposition strategy.

ACS Style

Pier Giorgio Schiavi; Antonio Rubino; Pietro Altimari; Francesca Pagnanelli. Two electrodeposition strategies for the morphology-controlled synthesis of cobalt nanostructures. EMERGING TECHNOLOGIES: MICRO TO NANO (ETMN-2017): Proceedings of the 3rd International Conference on Emerging Technologies: Micro to Nano 2018, 1990, 020005 .

AMA Style

Pier Giorgio Schiavi, Antonio Rubino, Pietro Altimari, Francesca Pagnanelli. Two electrodeposition strategies for the morphology-controlled synthesis of cobalt nanostructures. EMERGING TECHNOLOGIES: MICRO TO NANO (ETMN-2017): Proceedings of the 3rd International Conference on Emerging Technologies: Micro to Nano. 2018; 1990 (1):020005.

Chicago/Turabian Style

Pier Giorgio Schiavi; Antonio Rubino; Pietro Altimari; Francesca Pagnanelli. 2018. "Two electrodeposition strategies for the morphology-controlled synthesis of cobalt nanostructures." EMERGING TECHNOLOGIES: MICRO TO NANO (ETMN-2017): Proceedings of the 3rd International Conference on Emerging Technologies: Micro to Nano 1990, no. 1: 020005.

Journal article
Published: 01 January 2018 in Electrochimica Acta
Reads 0
Downloads 0

The electrodeposition of cobalt nanowires into nanoporous alumina templates produced by one-step anodization of low-purity aluminium was investigated. Aluminium was electropolished prior anodization to generate a hexagonal cell pattern, and a tree-like structure was introduced at the aluminium/aluminium oxide interface by progressively decreasing the anodization potential following potentiostatic anodization. Pulsed electrodeposition including the periodic application of a cathodic potential pulse with constant amplitude was performed to fill the generated alumina template by cobalt nanowires. With this strategy, cathodic potential pulses with amplitude lower than −5 V (vs. Ag/AgCl) were necessary to enforce uniform and instantaneous cobalt nucleation at the bottom of template nanopores, which allowed achieving uniform filling and narrow length distribution of the electrodeposited nanowires. However, the uniform growth of the nucleating cobalt nanowires could be sustained by considerably less cathodic potential pulses (up to −1.5 V vs. Ag/AgCl). Uniform filling of the alumina template could accordingly be achieved by a two-stage-pulsed electrodeposition strategy including the application of a high cathodic pulse (<−5 V) inducing uniform and instantaneous cobalt nucleation followed by the periodic application of a lower cathodic pulse (>−1.5 V) sustaining nanowire growth. The mechanisms that govern cobalt nucleation at the bottom of nanopores and the technical advantages of the proposed nanowire synthesis strategy are discussed

ACS Style

Pier Giorgio Schiavi; Pietro Altimari; Antonio Rubino; Francesca Pagnanelli. Electrodeposition of cobalt nanowires into alumina templates generated by one-step anodization. Electrochimica Acta 2018, 259, 711 -722.

AMA Style

Pier Giorgio Schiavi, Pietro Altimari, Antonio Rubino, Francesca Pagnanelli. Electrodeposition of cobalt nanowires into alumina templates generated by one-step anodization. Electrochimica Acta. 2018; 259 ():711-722.

Chicago/Turabian Style

Pier Giorgio Schiavi; Pietro Altimari; Antonio Rubino; Francesca Pagnanelli. 2018. "Electrodeposition of cobalt nanowires into alumina templates generated by one-step anodization." Electrochimica Acta 259, no. : 711-722.

Journal article
Published: 01 December 2016 in Electrochimica Acta
Reads 0
Downloads 0

Cobalt hexagonal nanoplatelets and cobalt nanoflakes were produced by electrodeposition onto aluminium from cobalt sulphate solutions. The dependence of the nanostructure morphology on cobalt ion concentration and potential was investigated under potentiostatic and pulsed-electrodeposition. Under potentiostatic electrodeposition, cobalt hexagonal nanoplatelets were obtained with cobalt ion concentration equal to 0.01 and 0.1 M, while cobalt hydroxide nanoflakes were formed as the cobalt ion concentration was increased to 0.2 M. Under pulsed electrodeposition, both hexagonal nanoplatelets and hydroxide nanoflakes could be obtained with cobalt ion concentration equal to 0.1 M by modulation of the imposed current/potential wave. The analysis of the current transients recorded under potentiostatic electrodeposition and the microscopic analysis of the deposits indicate that three-dimensional diffusion control cannot adequately describe the growth of the cobalt nanostructures. We propose that an aggregative growth mechanism involving the formation and the surface diffusion of cobalt nanoclusters can explain the influence of electrodeposition parameters on the morphology of the cobalt nanostructures. (C) 2016 Elsevier Ltd. All rights reserved

ACS Style

Pier Giorgio Schiavi; Pietro Altimari; Robertino Zanoni; Francesca Pagnanelli. Morphology-controlled synthesis of cobalt nanostructures by facile electrodeposition: transition from hexagonal nanoplatelets to nanoflakes. Electrochimica Acta 2016, 220, 405 -416.

AMA Style

Pier Giorgio Schiavi, Pietro Altimari, Robertino Zanoni, Francesca Pagnanelli. Morphology-controlled synthesis of cobalt nanostructures by facile electrodeposition: transition from hexagonal nanoplatelets to nanoflakes. Electrochimica Acta. 2016; 220 ():405-416.

Chicago/Turabian Style

Pier Giorgio Schiavi; Pietro Altimari; Robertino Zanoni; Francesca Pagnanelli. 2016. "Morphology-controlled synthesis of cobalt nanostructures by facile electrodeposition: transition from hexagonal nanoplatelets to nanoflakes." Electrochimica Acta 220, no. : 405-416.

Journal article
Published: 01 February 2015 in Electrochimica Acta
Reads 0
Downloads 0

Cobalt nanoparticles were synthesized by pulsed electrodeposition on copper substrate. Scanning\ud electron microscopy and image analysis were used to determine morphology and particle size\ud distribution of nanoparticle populations obtained in different operating conditions. After preliminary\ud tests, ton and toff were set at 50 and 300ms respectively to obtain distinct nanoparticles and avoid\ud dendritic structures. Experimental tests were performed according to two partially superimposed\ud factorial designs with two factors at two levels. First factorial design investigated the effect of current\ud density (I = 10 and 50mA/cm2) and discharged cobalt (Q = 2.5*10^3 and 1.0*10^2C); second factorial\ud design investigated the effect of cobalt concentration (C0 = 0.01 and 0.1M) for the same two levels of Q.\ud For optimized value of ton/toff, square and hexagonal shaped nanoparticles were obtained. Statistical\ud analysis evidenced that, for C0 = 0.1 mol/L, current density is the most influencing factor on mean size:\ud increasing I from 10 to 50mA/cm2 determined a diminution of mean size of 240 nm. For the same cobalt\ud concentration, increasing the deposition time (Q) determined an increase of mean size of 60 nm.\ud Diminishing the initial cobalt concentration from 0.1 to 0.01 mol/L determined an increase of mean size\ud from 10nm to 36 nm. For C0 = 0.01 mol/L nanoparticles grow reaching an optimal size (36 nm) and then,\ud increasing the time of deposition, optimal sized subunits tend to aggregate.\ud As for polydispersity of nanoparticles, statistical tests denoted that increasing I determined significant\ud reduction of variance, while increasing the time of deposition determined a significant increase of\ud variance

ACS Style

Francesca Pagnanelli; Pietro Altimari; Marco Bellagamba; Giuseppe Granata; Emanuela Moscardini; Pier Giorgio Schiavi; Luigi Toro. Pulsed electrodeposition of cobalt nanoparticles on copper: influence of the operating parameters on size distribution and morphology. Electrochimica Acta 2015, 155, 228 -235.

AMA Style

Francesca Pagnanelli, Pietro Altimari, Marco Bellagamba, Giuseppe Granata, Emanuela Moscardini, Pier Giorgio Schiavi, Luigi Toro. Pulsed electrodeposition of cobalt nanoparticles on copper: influence of the operating parameters on size distribution and morphology. Electrochimica Acta. 2015; 155 ():228-235.

Chicago/Turabian Style

Francesca Pagnanelli; Pietro Altimari; Marco Bellagamba; Giuseppe Granata; Emanuela Moscardini; Pier Giorgio Schiavi; Luigi Toro. 2015. "Pulsed electrodeposition of cobalt nanoparticles on copper: influence of the operating parameters on size distribution and morphology." Electrochimica Acta 155, no. : 228-235.