Elizabeth Castillo-martínez | University of Cambridge (original) (raw)

Papers by Elizabeth Castillo-martínez

ACS Applied Energy Materials

Sustainable Energy & Fuels, 2021

Sustainable and accessible energy? Green materials and batteries. We review the latest ecological... more Sustainable and accessible energy? Green materials and batteries. We review the latest ecological materials and technologies for off-grid battery applications.

ECS Meeting Abstracts, 2015

Sodium ion batteries (SIBs) are becoming an attractive alternative for stationary applications be... more Sodium ion batteries (SIBs) are becoming an attractive alternative for stationary applications because of their low cost: sodium is more abundant and easier to obtain than lithium and cheaper current collectors made of aluminium instead of copper can be used. While for cathode materials many lithium analogues can be successfully used in SIB [1], the challenge is to find alternative anode materials [2], the reasons being the impossibility of sodium insertion into graphite and the formation of a stable SEI layer (Solid Electrolyte Interphase). Na2Ti3O7 has been reported as the oxide with the lowest sodium insertion/deinsertion voltage at 0.3 V vs . Na+/Na and a capacity close to 200 mAh/g [3], becoming a very promising anode candidate both in terms of energy density and cost. However the reported capacity retention needs to be improved [4, 5] and the formation of a stable SEI layer remains to be proved. Here we present a study were the role of several synthesis parameters, such as the...

Materials Research Bulletin, 2017

Highlights  New Al,Mg-doped (Na [Ti(1-x)Mx]O2 layered oxide phases has been synthesised.  Negli... more Highlights  New Al,Mg-doped (Na [Ti(1-x)Mx]O2 layered oxide phases has been synthesised.  Negligible changes are observed in lattice parameters of doped samples.  Mg doping is confirmed by 23 Na ssNMR.  Al,Mg-doped are electrochemically active in the 0.05-1.6 V vs. Na/Na + range.  NaTi0.65Mg0.35O2 with a smoothening voltage profile and improved Crate .

Energy & Environmental Science, 2016

Common organic dyes show three stable redox states, offering an alternative to questionable vanad... more Common organic dyes show three stable redox states, offering an alternative to questionable vanadium for the implementation of redox-flow batteries.

Journal of Power Sources, 2016

h i g h l i g h t s g r a p h i c a l a b s t r a c t Transformation of Na 2 Ti 3 O 7 into Na 2Àx... more h i g h l i g h t s g r a p h i c a l a b s t r a c t Transformation of Na 2 Ti 3 O 7 into Na 2Àx H x Ti 3 O 7 (2 < x < 0) in contact with air or H 2 O. First structural resolution of Na 2Àx H x Ti 3 O 7 (x ¼ 1.4, x ¼ 0.7) by neutron diffraction. Na 2Àx H x Ti 3 O 7 (2 < x 0) transforms into Na 2 Ti 3 O 7 after the first cycle in a Na half-cell. CMC binder improves the electrochemical performance of Na 2 Ti 3 O 7 .

Electrochimica Acta, 2016

Abstract Na-ion batteries (NIB) are now attracting researchers’ attention as possible substitutes... more Abstract Na-ion batteries (NIB) are now attracting researchers’ attention as possible substitutes of Li-ion batteries. Promising cathode materials, which have demonstrated to work well for NIB are those based on the sodiated Prussian Blue, NaFeFe(CN) 6 , Prussian White, Na 2 FeFe(CN) 6 , and their analogues. Herein, the effect of different electrolytes and binder composition, on the electrochemical performance of sodium Prussian Blue, Na 0.75 Fe 2.08 (CN) 6 ·3.4H 2 O, as cathode material for NIB is studied. Several electrolytes containing NaClO 4 or NaPF 6 salts in carbonated mixtures, with and without fluoroethylene carbonate (FEC) as additive, have been tested for Na 0.75 Fe 2.08 (CN) 6 ·3.4H 2 O. The effect of different binders, polyvinylidene fluoride (PvdF), sodium carboxymethyl cellulose (CMC), polytetrafluoroethylene (PTFE) and ethylene propylene diene monomer ruber (EPDM), is also investigated.

Acta Materialia, 2016

Abstract Na 2 Ti 3 O 7 is a promising insertion anode material for Na-ion batteries owing to its ... more Abstract Na 2 Ti 3 O 7 is a promising insertion anode material for Na-ion batteries owing to its low reaction voltage (0.3 V vs . Na + /Na) and high specific capacity (178 mAh/g). However, such promising attributes are shaded by the poor capacity retention that has so far been obtained for this material. Here the impact of solid state synthesis parameters on the electrochemical properties is reported and, in particular, on the capacity retention. In agreement with 23 Na solid state NMR and FTIR it has been found that small amounts of insulating Na 2 CO 3 , either from unreacted precursor or formed by surface corrosion, strongly contribute to the capacity fading. These were avoided by eluding Na 2 CO 3 as a precursor and preventing hydration of the samples by controlling the atmosphere of the cooling process. Once the synthesis conditions were optimized a Na 2 CO 3 free sample was carbon-coated to enhance the electrochemical properties obtaining the best charge capacity retention reported up to date after 100 cycles (78%) with a measured capacity of 124 mAh/g.

Electrochimica Acta, 2016

Cabanas, Electrochemical characterization of NaFe2(CN)6 Prussian Blue as positive electrode for a... more Cabanas, Electrochemical characterization of NaFe2(CN)6 Prussian Blue as positive electrode for aqueous sodium-ion batteries, Electrochimica Acta http://dx.

Prussian Blue Based Batteries, 2018

Aqueous batteries offer lower cost compared to non-aqueous batteries and higher ionic mobility, t... more Aqueous batteries offer lower cost compared to non-aqueous batteries and higher ionic mobility, thus potentially higher power, which are the driving forces for their commercialization. On the other hand, water-based electrolytes present a more limited voltage stability window (ca. 1.23 V) than organic electrolytes, what translates into storing lower energy densities than non-aqueous batteries. However, as we will see, there are several ways to enlarge this voltage window, such as modifying the salt chosen and its concentration.

Advanced Sustainable Systems, 2022

Electrochimica Acta, 2020

Abstract The lithium ion storage properties of a series of metal-organic frameworks (MOFs) with f... more Abstract The lithium ion storage properties of a series of metal-organic frameworks (MOFs) with formula {[M(L)(H2O)2]H2O}n and [M(CA)(Pyz)]n (where L refers to the tetraoxolene ligands: CA = chloranilate and DHBQ = dihydroxybenzoquinone; Pyz = pyrazine; M = Fe and Mn) and exhibiting a 1D and 2D structure, respectively, have been studied. The 1D MOFs ({[M(L)(H2O)2]H2O}n) show higher reversible capacity values for lithium ion insertion with respect to 2D structures containing two organic ligands (M(CA)(Pyz)]n). The gravimetric capacity for the 1D Fe-CA MOF is 75 mAh/g at 2.16 mA/g (∼ 1 lithium atom per formula unit) higher than for the Mn complexes which is 65 mAh/g at 2.12 mA/g, though isostructural. Lithium ion insertion in the 1D Mn-CA chains takes place at 2.4 V vs. Li+/Li which is ∼700 mV higher than what is recorded for the Fe analogue. This result is most probably due to much more stable d5 electronic configuration of Mn2+ than d6 of Fe2+ in its isostructural Fe-based framework analogue of the final reduced phases. The 1D Fe-DHBQ capacity is higher than its manganese analogue 75 mAh/g at 2.5 mA/g (0.8 lithiums) against 40 mAh/g. In general, the high voltages of reaction in these 1D MOFs suggest that they involve the participation of the ligand on the redox processes along with the reduction of the transition metal if any. In fact, the potential of ion insertion changed depending on the metal. This fact along with the absence of evidence of conversion reaction by x-ray diffraction of cycled electrodes suggests that the charge delocalization may be all along the metal-ligand molecular framework participating as a whole hybrid unit in the lithium storage.

Prussian Blue Based Batteries, 2018

espanolLos dispositivos de almacenamiento de energia electroquimica juegan un papel cada vez mas ... more espanolLos dispositivos de almacenamiento de energia electroquimica juegan un papel cada vez mas importante en nuestra sociedad y los materiales polimericos son componentes criticos de estos dispositivos. Con la creciente demanda de baterias de alta densidad energetica, se hace necesario preparar nuevos materiales que, fabricados sobre el conocimiento fundamental de los fenomenos fisicos y propiedades estructura-funcion de los anteriores, den lugar a la nueva generacion de baterias. En este articulo se describen las bases de Schiff polimericas como potencial material activo en los anodos para baterias de ion sodio de bajo coste para aplicaciones de gran escala. Especificamente, se propone el diseno de materiales polimericos avanzados con las siguientes propiedades deseadas: adhesion mecanica al colector de corriente, alta capacidad, alta conductividad ionica y electronica e interacciones quimicas especificas. Estos polimeros cumplen los criterios de requerir una materia prima abunda...

En este trabajo hemos empleado la alta presion para estabilizar perovskitas con un cation B reput... more En este trabajo hemos empleado la alta presion para estabilizar perovskitas con un cation B reputado inestable en coordinacion octaedrica con oxigeno, como es el Cr(IV). Las fases preparadas han sido caracterizadas plenamente en terminos estructurales por difraccion de rayos-X y microscopia electronica de transmision, y en ellas se han efectuado medidas magneticas, electricas y en algunos casos de calor especifico. En concreto se han sintetizado 3 tipos de fases. 1) La disolucion solida Sr1-xCaxCrO3 tipo perovskita, 2) Las fases denominadas de Ruddlesden-Popper, de formula general Srn+1CrnO3n+2)- Tambien hemos descubierto nuevas fases de las denominadas discordantes, "misfit layer structure". Por ultimo y tambien por medio de alta presion, hemos conseguido transformar un compuesto con estructura tipo bixbyita en perovskita, ScIIIVIIIO3, que presenta la mayor distorsion octahedrica conocida hasta el momento.

Prussian Blue Based Batteries, 2018

Electrochemistry is the science dedicated to study the relationship existent between the occurren... more Electrochemistry is the science dedicated to study the relationship existent between the occurrence of certain chemical processes and the electrical current needed or generated during such chemical processes.

Prussian Blue Based Batteries, 2018

Prussian Blue is a mixed-valence polynuclear transition metal cyanide complex (Samain et al. in J... more Prussian Blue is a mixed-valence polynuclear transition metal cyanide complex (Samain et al. in J Phys Chem C 117:9693–9712, 2013, [1]), (Ludi in Descriptive chemistry of mixed-valence compounds. Springer, Dordrecht, 1980, [2]) and it can be considered the first synthetic coordination compound (Davies et al. in Synthetic coordination chemistry: principles and practice. World Scientific, Singapore, 1996, [3]). The discovery of Prussian Blue dates back to early eighteenth century, around 1704. Its invention has been attributed to a colour manufacturer from Berlin named Diesbach, who apparently obtained the blue compound accidentally when he was preparing another pigment (Stahl in Experimenta, observations, animad-versiones, CCC numero, chymicae et physicae. Berlin, 1731, [4]).

Journal of the American Chemical Society, 2017

ACS Applied Energy Materials

Sustainable Energy & Fuels, 2021

Sustainable and accessible energy? Green materials and batteries. We review the latest ecological... more Sustainable and accessible energy? Green materials and batteries. We review the latest ecological materials and technologies for off-grid battery applications.

ECS Meeting Abstracts, 2015

Sodium ion batteries (SIBs) are becoming an attractive alternative for stationary applications be... more Sodium ion batteries (SIBs) are becoming an attractive alternative for stationary applications because of their low cost: sodium is more abundant and easier to obtain than lithium and cheaper current collectors made of aluminium instead of copper can be used. While for cathode materials many lithium analogues can be successfully used in SIB [1], the challenge is to find alternative anode materials [2], the reasons being the impossibility of sodium insertion into graphite and the formation of a stable SEI layer (Solid Electrolyte Interphase). Na2Ti3O7 has been reported as the oxide with the lowest sodium insertion/deinsertion voltage at 0.3 V vs . Na+/Na and a capacity close to 200 mAh/g [3], becoming a very promising anode candidate both in terms of energy density and cost. However the reported capacity retention needs to be improved [4, 5] and the formation of a stable SEI layer remains to be proved. Here we present a study were the role of several synthesis parameters, such as the...

Materials Research Bulletin, 2017

Highlights  New Al,Mg-doped (Na [Ti(1-x)Mx]O2 layered oxide phases has been synthesised.  Negli... more Highlights  New Al,Mg-doped (Na [Ti(1-x)Mx]O2 layered oxide phases has been synthesised.  Negligible changes are observed in lattice parameters of doped samples.  Mg doping is confirmed by 23 Na ssNMR.  Al,Mg-doped are electrochemically active in the 0.05-1.6 V vs. Na/Na + range.  NaTi0.65Mg0.35O2 with a smoothening voltage profile and improved Crate .

Energy & Environmental Science, 2016

Common organic dyes show three stable redox states, offering an alternative to questionable vanad... more Common organic dyes show three stable redox states, offering an alternative to questionable vanadium for the implementation of redox-flow batteries.

Journal of Power Sources, 2016

h i g h l i g h t s g r a p h i c a l a b s t r a c t Transformation of Na 2 Ti 3 O 7 into Na 2Àx... more h i g h l i g h t s g r a p h i c a l a b s t r a c t Transformation of Na 2 Ti 3 O 7 into Na 2Àx H x Ti 3 O 7 (2 < x < 0) in contact with air or H 2 O. First structural resolution of Na 2Àx H x Ti 3 O 7 (x ¼ 1.4, x ¼ 0.7) by neutron diffraction. Na 2Àx H x Ti 3 O 7 (2 < x 0) transforms into Na 2 Ti 3 O 7 after the first cycle in a Na half-cell. CMC binder improves the electrochemical performance of Na 2 Ti 3 O 7 .

Electrochimica Acta, 2016

Abstract Na-ion batteries (NIB) are now attracting researchers’ attention as possible substitutes... more Abstract Na-ion batteries (NIB) are now attracting researchers’ attention as possible substitutes of Li-ion batteries. Promising cathode materials, which have demonstrated to work well for NIB are those based on the sodiated Prussian Blue, NaFeFe(CN) 6 , Prussian White, Na 2 FeFe(CN) 6 , and their analogues. Herein, the effect of different electrolytes and binder composition, on the electrochemical performance of sodium Prussian Blue, Na 0.75 Fe 2.08 (CN) 6 ·3.4H 2 O, as cathode material for NIB is studied. Several electrolytes containing NaClO 4 or NaPF 6 salts in carbonated mixtures, with and without fluoroethylene carbonate (FEC) as additive, have been tested for Na 0.75 Fe 2.08 (CN) 6 ·3.4H 2 O. The effect of different binders, polyvinylidene fluoride (PvdF), sodium carboxymethyl cellulose (CMC), polytetrafluoroethylene (PTFE) and ethylene propylene diene monomer ruber (EPDM), is also investigated.

Acta Materialia, 2016

Abstract Na 2 Ti 3 O 7 is a promising insertion anode material for Na-ion batteries owing to its ... more Abstract Na 2 Ti 3 O 7 is a promising insertion anode material for Na-ion batteries owing to its low reaction voltage (0.3 V vs . Na + /Na) and high specific capacity (178 mAh/g). However, such promising attributes are shaded by the poor capacity retention that has so far been obtained for this material. Here the impact of solid state synthesis parameters on the electrochemical properties is reported and, in particular, on the capacity retention. In agreement with 23 Na solid state NMR and FTIR it has been found that small amounts of insulating Na 2 CO 3 , either from unreacted precursor or formed by surface corrosion, strongly contribute to the capacity fading. These were avoided by eluding Na 2 CO 3 as a precursor and preventing hydration of the samples by controlling the atmosphere of the cooling process. Once the synthesis conditions were optimized a Na 2 CO 3 free sample was carbon-coated to enhance the electrochemical properties obtaining the best charge capacity retention reported up to date after 100 cycles (78%) with a measured capacity of 124 mAh/g.

Electrochimica Acta, 2016

Cabanas, Electrochemical characterization of NaFe2(CN)6 Prussian Blue as positive electrode for a... more Cabanas, Electrochemical characterization of NaFe2(CN)6 Prussian Blue as positive electrode for aqueous sodium-ion batteries, Electrochimica Acta http://dx.

Prussian Blue Based Batteries, 2018

Aqueous batteries offer lower cost compared to non-aqueous batteries and higher ionic mobility, t... more Aqueous batteries offer lower cost compared to non-aqueous batteries and higher ionic mobility, thus potentially higher power, which are the driving forces for their commercialization. On the other hand, water-based electrolytes present a more limited voltage stability window (ca. 1.23 V) than organic electrolytes, what translates into storing lower energy densities than non-aqueous batteries. However, as we will see, there are several ways to enlarge this voltage window, such as modifying the salt chosen and its concentration.

Advanced Sustainable Systems, 2022

Electrochimica Acta, 2020

Abstract The lithium ion storage properties of a series of metal-organic frameworks (MOFs) with f... more Abstract The lithium ion storage properties of a series of metal-organic frameworks (MOFs) with formula {[M(L)(H2O)2]H2O}n and [M(CA)(Pyz)]n (where L refers to the tetraoxolene ligands: CA = chloranilate and DHBQ = dihydroxybenzoquinone; Pyz = pyrazine; M = Fe and Mn) and exhibiting a 1D and 2D structure, respectively, have been studied. The 1D MOFs ({[M(L)(H2O)2]H2O}n) show higher reversible capacity values for lithium ion insertion with respect to 2D structures containing two organic ligands (M(CA)(Pyz)]n). The gravimetric capacity for the 1D Fe-CA MOF is 75 mAh/g at 2.16 mA/g (∼ 1 lithium atom per formula unit) higher than for the Mn complexes which is 65 mAh/g at 2.12 mA/g, though isostructural. Lithium ion insertion in the 1D Mn-CA chains takes place at 2.4 V vs. Li+/Li which is ∼700 mV higher than what is recorded for the Fe analogue. This result is most probably due to much more stable d5 electronic configuration of Mn2+ than d6 of Fe2+ in its isostructural Fe-based framework analogue of the final reduced phases. The 1D Fe-DHBQ capacity is higher than its manganese analogue 75 mAh/g at 2.5 mA/g (0.8 lithiums) against 40 mAh/g. In general, the high voltages of reaction in these 1D MOFs suggest that they involve the participation of the ligand on the redox processes along with the reduction of the transition metal if any. In fact, the potential of ion insertion changed depending on the metal. This fact along with the absence of evidence of conversion reaction by x-ray diffraction of cycled electrodes suggests that the charge delocalization may be all along the metal-ligand molecular framework participating as a whole hybrid unit in the lithium storage.

Prussian Blue Based Batteries, 2018

espanolLos dispositivos de almacenamiento de energia electroquimica juegan un papel cada vez mas ... more espanolLos dispositivos de almacenamiento de energia electroquimica juegan un papel cada vez mas importante en nuestra sociedad y los materiales polimericos son componentes criticos de estos dispositivos. Con la creciente demanda de baterias de alta densidad energetica, se hace necesario preparar nuevos materiales que, fabricados sobre el conocimiento fundamental de los fenomenos fisicos y propiedades estructura-funcion de los anteriores, den lugar a la nueva generacion de baterias. En este articulo se describen las bases de Schiff polimericas como potencial material activo en los anodos para baterias de ion sodio de bajo coste para aplicaciones de gran escala. Especificamente, se propone el diseno de materiales polimericos avanzados con las siguientes propiedades deseadas: adhesion mecanica al colector de corriente, alta capacidad, alta conductividad ionica y electronica e interacciones quimicas especificas. Estos polimeros cumplen los criterios de requerir una materia prima abunda...

En este trabajo hemos empleado la alta presion para estabilizar perovskitas con un cation B reput... more En este trabajo hemos empleado la alta presion para estabilizar perovskitas con un cation B reputado inestable en coordinacion octaedrica con oxigeno, como es el Cr(IV). Las fases preparadas han sido caracterizadas plenamente en terminos estructurales por difraccion de rayos-X y microscopia electronica de transmision, y en ellas se han efectuado medidas magneticas, electricas y en algunos casos de calor especifico. En concreto se han sintetizado 3 tipos de fases. 1) La disolucion solida Sr1-xCaxCrO3 tipo perovskita, 2) Las fases denominadas de Ruddlesden-Popper, de formula general Srn+1CrnO3n+2)- Tambien hemos descubierto nuevas fases de las denominadas discordantes, "misfit layer structure". Por ultimo y tambien por medio de alta presion, hemos conseguido transformar un compuesto con estructura tipo bixbyita en perovskita, ScIIIVIIIO3, que presenta la mayor distorsion octahedrica conocida hasta el momento.

Prussian Blue Based Batteries, 2018

Electrochemistry is the science dedicated to study the relationship existent between the occurren... more Electrochemistry is the science dedicated to study the relationship existent between the occurrence of certain chemical processes and the electrical current needed or generated during such chemical processes.

Prussian Blue Based Batteries, 2018

Prussian Blue is a mixed-valence polynuclear transition metal cyanide complex (Samain et al. in J... more Prussian Blue is a mixed-valence polynuclear transition metal cyanide complex (Samain et al. in J Phys Chem C 117:9693–9712, 2013, [1]), (Ludi in Descriptive chemistry of mixed-valence compounds. Springer, Dordrecht, 1980, [2]) and it can be considered the first synthetic coordination compound (Davies et al. in Synthetic coordination chemistry: principles and practice. World Scientific, Singapore, 1996, [3]). The discovery of Prussian Blue dates back to early eighteenth century, around 1704. Its invention has been attributed to a colour manufacturer from Berlin named Diesbach, who apparently obtained the blue compound accidentally when he was preparing another pigment (Stahl in Experimenta, observations, animad-versiones, CCC numero, chymicae et physicae. Berlin, 1731, [4]).

Journal of the American Chemical Society, 2017