Teófilo Rojo Aparicio - Academia.edu (original) (raw)
Uploads
Papers by Teófilo Rojo Aparicio
Boletin De La Sociedad Espanola De Mineralogia, 2002
Chemistry of Materials, 2016
Magnesium substituted P2-structure Na 0.67 Ni 0.3 Mn 0.7 O 2 materials have been prepared by a fa... more Magnesium substituted P2-structure Na 0.67 Ni 0.3 Mn 0.7 O 2 materials have been prepared by a facile solid-state method and investigated as cathodes in sodium-ion batteries. The Mg-doped materials described here were characterized by Xray diffraction (XRD), 23 Na solid-state nuclear magnetic resonance (SS-NMR), and scanning electron microscopy (SEM). The electrochemical performance of the samples was tested in half cells vs Na metal at room temperature. The Mg-doped materials operate at a high average voltage of ca. 3.3 V vs Na/Na + delivering specific capacities of ∼120 mAh g −1 , which remain stable up to 50 cycles. Mg doping suppresses the well-known P2−O2 phase transition observed in the undoped composition by stabilizing the reversible OP4 phase during charging (during Na removal). GITT measurements showed that the Na-ion mobility is improved by 2 orders of magnitude with respect to the parent P2−Na 0.67 Ni 0.3 Mn 0.7 O 2 material. The fast Na-ion mobility may be the cause of the enhanced rate performance.
Journal of The Electrochemical Society, 2019
The need for sustainable energy sources and their efficient utilization has motivated extensive e... more The need for sustainable energy sources and their efficient utilization has motivated extensive explorations of new electrolytes, electrodes, and alternative battery chemistries departing from current lithium-ion battery (LIB) technologies. The evolution and development of rechargeable batteries are tightly linked to the research of polymeric materials, such as polymer electrolytes and redox-active polymeric electrodes, separators, and binders, etc… In this contribution, we review the recent progresses on polymer electrolytes and redox-active polymeric electrodes developed in CIC Energigune with particular attention paid to the molecular designing and engineering. On the basis of our knowledge and experience accumulated in rechargeable batteries, further developments and improvements on the properties of these polymeric materials for building better rechargeable batteries are discussed.
Journal of The Electrochemical Society, 2019
Herein we report a series of lithium ion capacitors (LICs) with extraordinary energy-to-power rat... more Herein we report a series of lithium ion capacitors (LICs) with extraordinary energy-to-power ratios based on olive pit recycled carbons and supported on graphene as a conducting matrix. LICs typically present limited energy densities at high power densities due to the sluggish kinetics of the battery-type electrode. To circumvent this limitation, the hard carbon (HC) was embedded in a reduced graphene oxide (rGO) matrix. The addition of rGO into the negative electrode not only forms a 3D interpenetrating carbon network but also wraps HC particles, facilitating ion diffusion and enhancing the electronic conductivity notably at high power densities. Electrochemical impedance spectroscopy (EIS) analysis reveals that charge-transfer resistance at electrode-electrolyte interphase and the charge-transport resistance within the electrode are considerably lower in the presence of rGO. In addition, charge-transport resistance remains constant upon cycling even at increasing current densities. Capacity gain at high current densities, owing to the reduction of the electrode resistance, triggers the overall LIC performance, allowing for the assembly of an ultrafast LIC delivering up to 200 Wh kg −1 AM at low power rates and 100 Wh kg −1 AM at a power of 10 kW kg −1 AM .
Molecules, 2020
Silicon-based anodes are extensively studied as an alternative to graphite for lithium ion batter... more Silicon-based anodes are extensively studied as an alternative to graphite for lithium ion batteries. However, silicon particles suffer larges changes in their volume (about 280%) during cycling, which lead to particles cracking and breakage of the solid electrolyte interphase. This process induces continuous irreversible electrolyte decomposition that strongly reduces the battery life. In this research work, different silicon@graphite anodes have been prepared through a facile and scalable ball milling synthesis and have been tested in lithium batteries. The morphology and structure of the different samples have been studied using X-ray diffraction, X-ray photoelectron spectroscopy, Raman spectroscopy, and scanning and transmission electron microscopy. We show how the incorporation of an organic solvent in the synthesis procedure prevents particles agglomeration and leads to a suitable distribution of particles and intimate contact between them. Moreover, the importance of the micr...
Advanced Energy Materials, 2020
technologies. Unlike lithium, whose market is already very tight, sodium mineral deposits are alm... more technologies. Unlike lithium, whose market is already very tight, sodium mineral deposits are almost infinite, evenly distributed worldwide, much easier to extract and thereby attainable at low cost. [1-4] If the realization of Na-rechargeable batteries could be practically possible, there will be nearly three orders of magnitude relaxation in the constraints on lithium-based resources, accompanied by sustainability, improved environmental benevolence, and cost reduction (Table 1). Even more appealing is the possible use of the widely available and lighter aluminum, rather than copper, as negative current collector and hard carbon from renewable sources instead of graphite for the negative electrode. Finally, the stability of sodium-ion batteries (SIBs) in the fully discharged state would significantly enhance the safety associated with the shipment of large-format SIBs worldwide. These beneficial features of sodiumbased cells revived the research work on Na-based rechargeable batteries and accordingly captured the attention of both the academic research and industry sectors. However, similar to LIB, most of the research work in Na-based batteries have focused on the development and elaboration of negative and positive For sodium (Na)-rechargeable batteries to compete, and go beyond the currently prevailing Li-ion technologies, mastering the chemistry and accompanying phenomena is of supreme importance. Among the crucial components of the battery system, the electrolyte, which bridges the highly polarized positive and negative electrode materials, is arguably the most critical and indispensable of all. The electrolyte dictates the interfacial chemistry of the battery and the overall performance, having an influence over the practical capacity, rate capability (power), chemical/thermal stress (safety), and lifetime. In-depth knowledge of electrolyte properties provides invaluable information to improve the design, assembly, and operation of the battery. Thus, the full-scale appraisal of both tailored electrolytes and the concomitant interphases generated at the electrodes need to be prioritized. The deployment of large-format Na-based rechargeable batteries also necessitates systematic evaluation and detailed appraisal of the safety-related hazards of Na-based batteries. Hence, this review presents a comprehensive account of the progress, status, and prospect of various Na +-ion electrolytes, including solvents, salts and additives, their interphases and potential hazards.
Boletin De La Sociedad Espanola De Mineralogia, 2002
Chemistry of Materials, 2016
Magnesium substituted P2-structure Na 0.67 Ni 0.3 Mn 0.7 O 2 materials have been prepared by a fa... more Magnesium substituted P2-structure Na 0.67 Ni 0.3 Mn 0.7 O 2 materials have been prepared by a facile solid-state method and investigated as cathodes in sodium-ion batteries. The Mg-doped materials described here were characterized by Xray diffraction (XRD), 23 Na solid-state nuclear magnetic resonance (SS-NMR), and scanning electron microscopy (SEM). The electrochemical performance of the samples was tested in half cells vs Na metal at room temperature. The Mg-doped materials operate at a high average voltage of ca. 3.3 V vs Na/Na + delivering specific capacities of ∼120 mAh g −1 , which remain stable up to 50 cycles. Mg doping suppresses the well-known P2−O2 phase transition observed in the undoped composition by stabilizing the reversible OP4 phase during charging (during Na removal). GITT measurements showed that the Na-ion mobility is improved by 2 orders of magnitude with respect to the parent P2−Na 0.67 Ni 0.3 Mn 0.7 O 2 material. The fast Na-ion mobility may be the cause of the enhanced rate performance.
Journal of The Electrochemical Society, 2019
The need for sustainable energy sources and their efficient utilization has motivated extensive e... more The need for sustainable energy sources and their efficient utilization has motivated extensive explorations of new electrolytes, electrodes, and alternative battery chemistries departing from current lithium-ion battery (LIB) technologies. The evolution and development of rechargeable batteries are tightly linked to the research of polymeric materials, such as polymer electrolytes and redox-active polymeric electrodes, separators, and binders, etc… In this contribution, we review the recent progresses on polymer electrolytes and redox-active polymeric electrodes developed in CIC Energigune with particular attention paid to the molecular designing and engineering. On the basis of our knowledge and experience accumulated in rechargeable batteries, further developments and improvements on the properties of these polymeric materials for building better rechargeable batteries are discussed.
Journal of The Electrochemical Society, 2019
Herein we report a series of lithium ion capacitors (LICs) with extraordinary energy-to-power rat... more Herein we report a series of lithium ion capacitors (LICs) with extraordinary energy-to-power ratios based on olive pit recycled carbons and supported on graphene as a conducting matrix. LICs typically present limited energy densities at high power densities due to the sluggish kinetics of the battery-type electrode. To circumvent this limitation, the hard carbon (HC) was embedded in a reduced graphene oxide (rGO) matrix. The addition of rGO into the negative electrode not only forms a 3D interpenetrating carbon network but also wraps HC particles, facilitating ion diffusion and enhancing the electronic conductivity notably at high power densities. Electrochemical impedance spectroscopy (EIS) analysis reveals that charge-transfer resistance at electrode-electrolyte interphase and the charge-transport resistance within the electrode are considerably lower in the presence of rGO. In addition, charge-transport resistance remains constant upon cycling even at increasing current densities. Capacity gain at high current densities, owing to the reduction of the electrode resistance, triggers the overall LIC performance, allowing for the assembly of an ultrafast LIC delivering up to 200 Wh kg −1 AM at low power rates and 100 Wh kg −1 AM at a power of 10 kW kg −1 AM .
Molecules, 2020
Silicon-based anodes are extensively studied as an alternative to graphite for lithium ion batter... more Silicon-based anodes are extensively studied as an alternative to graphite for lithium ion batteries. However, silicon particles suffer larges changes in their volume (about 280%) during cycling, which lead to particles cracking and breakage of the solid electrolyte interphase. This process induces continuous irreversible electrolyte decomposition that strongly reduces the battery life. In this research work, different silicon@graphite anodes have been prepared through a facile and scalable ball milling synthesis and have been tested in lithium batteries. The morphology and structure of the different samples have been studied using X-ray diffraction, X-ray photoelectron spectroscopy, Raman spectroscopy, and scanning and transmission electron microscopy. We show how the incorporation of an organic solvent in the synthesis procedure prevents particles agglomeration and leads to a suitable distribution of particles and intimate contact between them. Moreover, the importance of the micr...
Advanced Energy Materials, 2020
technologies. Unlike lithium, whose market is already very tight, sodium mineral deposits are alm... more technologies. Unlike lithium, whose market is already very tight, sodium mineral deposits are almost infinite, evenly distributed worldwide, much easier to extract and thereby attainable at low cost. [1-4] If the realization of Na-rechargeable batteries could be practically possible, there will be nearly three orders of magnitude relaxation in the constraints on lithium-based resources, accompanied by sustainability, improved environmental benevolence, and cost reduction (Table 1). Even more appealing is the possible use of the widely available and lighter aluminum, rather than copper, as negative current collector and hard carbon from renewable sources instead of graphite for the negative electrode. Finally, the stability of sodium-ion batteries (SIBs) in the fully discharged state would significantly enhance the safety associated with the shipment of large-format SIBs worldwide. These beneficial features of sodiumbased cells revived the research work on Na-based rechargeable batteries and accordingly captured the attention of both the academic research and industry sectors. However, similar to LIB, most of the research work in Na-based batteries have focused on the development and elaboration of negative and positive For sodium (Na)-rechargeable batteries to compete, and go beyond the currently prevailing Li-ion technologies, mastering the chemistry and accompanying phenomena is of supreme importance. Among the crucial components of the battery system, the electrolyte, which bridges the highly polarized positive and negative electrode materials, is arguably the most critical and indispensable of all. The electrolyte dictates the interfacial chemistry of the battery and the overall performance, having an influence over the practical capacity, rate capability (power), chemical/thermal stress (safety), and lifetime. In-depth knowledge of electrolyte properties provides invaluable information to improve the design, assembly, and operation of the battery. Thus, the full-scale appraisal of both tailored electrolytes and the concomitant interphases generated at the electrodes need to be prioritized. The deployment of large-format Na-based rechargeable batteries also necessitates systematic evaluation and detailed appraisal of the safety-related hazards of Na-based batteries. Hence, this review presents a comprehensive account of the progress, status, and prospect of various Na +-ion electrolytes, including solvents, salts and additives, their interphases and potential hazards.