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Several spinel series with general formula LiTi2-xMxO4, with M = V, Cr, Fe and Co, have been studied in view of a possible structural transition to a ramsdellite form at high temperatures. Starting from the spinel structure, new ramsdellite families are prepared in the case of M = V and Cr, leading to the new solid solutions LiTi2-xVxO4 and LiTi2-xCrxO4 with 0 ≤ x ≤ 1. Structural characterisation of the new oxides has been performed by means of X-ray powder diffraction. In addition, magnetic properties of chromium compounds have been determined. The results obtained from both magnetic measurements and electrochemical intercalation studies confirm that cationic substitution in ramsdellite LiTi2O4 (e.g. formally as LiTi3+Ti4+O4), has an effect on the trivalent titanium cation, which is replaced by Cr3+ or V3+. The electrochemical behaviour of the series LiTi2-xVxO4 makes these oxides useful as negative electrode in rechargeable lithium ion batteries. Electrodes consisting of LiTi2-xVxO4 would develop at 1.5 volts reversible capacities of about 160 mAh/g, value which is close to that described for the parent LiTi2O4. We would like to remark the versatile behaviour of the new ramsdellite series LiTi2- xCrxO4. A detailed study of the intercalation electrochemistry of the member with x = 1, e.g. LiTiCrO4, shows that this new material may be useful as the negative electrode in rechargeable lithium ion batteries. Amaximal theoretical capacity of 157 mAh/g is developed at an average potential of 1.5 Volts When an electrochemical oxidation under a density current of 0.1 mA/cm2 is performed on LiTiCrO4, the compound develops a capacity of 90 mAh/g at an average potential of 4 Volts. Hence, this ramsdellite may also be useful for the positive electrode in lithium batteries.Se han investigado las posibles transformaciones a alta temperatura de diversas espinelas del tipo LiTi2-xMxO4 con M = V, Cr, Fe y Co, habiéndose determinado que es posible la obtención de nuevas rasmdellitas LiTi2-xVxO4 y LiTi2-xCrxO4 con 0 ≤ x ≤ 1. La caracterización estructural mediante difracción de rayos X y las medidas de susceptibilidad magnética realizadas para el caso del cromo, en unión de los datos aportados por el estudio electroquímico realizado, han permitido establecer que la sustitución catiónica lleva a compuestos del tipo Li(Ti3+)1-xMx(Ti4+)O4 con M = V3+ o Cr3+. El comportamiento electroquímico de LiTi2- xVxO4 permite proponer su posible uso como electrodo negativo en baterías de ion litio, ya que estos nuevos electrodos desarrollan capacidades de 160 mAh/g a un potencial medio de 1.5 V, valores que resultan similares a los del compuesto sin sustituir, la ramsdellita LiTi2O4 (166 mAh/g). Hay que destacar el comportamiento versátil de una nueva familia de ramsdellitas, LiTi2-xCrxO4. El estudio presentado sobre el miembro de esta familia con x = 1, la composición que se ha considerado más relevante, ha permitido proponer a este nuevo material como un buen candidato a electrodo negativo en baterías recargables de litio. Además de poder desarrollar en reducción, una capacidad máxima de 157 mAh/g a un potencial medio de 1.5 V, el material puede desarrollar en oxidación una capacidad de unos 90 mAh/g bajo una densidad de corriente de 0.1 mA/cm2 , por lo que podría actuar como el electrodo positivo, ya que en este caso el potencial medio de trabajo sería de 4 V.

The so called Electrochemical Potential Spectroscopy has been used to characterise several intercalation systems. The technique has shown its usefulness to study the different phases that form when an intercalation reaction occurs. Once the existence domains are determined, the work dedicated to the preparation of samples, in order to perform the structural characterisation, is very much shortened. We also present some cases where the above referred electrochemical technique does not yield good results in as much as the existence domains are not well determined. These are the cases of reactions with a very slow kinetic of intercalation and those where displacement reaction occurs. Some problems with experimental set up can also prevent us of using this technique.Se ha aplicado la técnica electroquímica que ha dado en llamarse Espectroscopía de Potencial Electroquímico a varios sistemas de intercalación redox para mostrar que ésta se presenta como una herramienta útil para el estudio de las fases presentes en dichos sistemas reduciendo considerablemente el trabajo de síntesis y caracterización estructural de compuestos formados en reacciones de intercalación redox. Puede así determinarse de una forma sencilla el número de fases presentes antes de proceder a su síntesis y posterior caracterización. Por otro lado se presentan algunas de las limitaciones de uso que presenta esta técnica. En particular los margenes de composición determinados no resultan fiables cuando se aplica a compuestos en los que la cinética de reacción es muy lenta o en los que se producen reacciones desplazamiento. De igual forma se ha establecido cuál es el límite de uso de esta técnica (5.3 V) en el caso de procesos de oxidación que se estudien usando la nueva generación de electrolitos estables por encima de 4.6 V.

The effect of mechanical grinding on the electrochemical properties of Li2Ti3O7 regarding lithium insertion is studied. X-ray diffraction experiments of milling compounds showed a progressively amorphization of the crystalline material due to both crystalline size decreasing and internal strain increasing. These structural modifications are reflected in the electrochemical behavior of Li2Ti3O7, when it is used as the positive electrode in lithium cells. As a function of milling time a higher specific capacity is obtained during the first discharge of the cell, but when charging an increasing in the irreversible capacity is observed. The most promising Li2Ti3O7 based electrode has been achieved, under our experimental conditions, for 13 hours milling that produces a compound with crystallite size of approximately 20 nm. [ABSTRACT FROM AUTHOR]

Abstract: Li2Ti6O13 has been prepared from Na2Ti6O13 by Li ion exchange in molten LiNO3 at 325°C. Chemical analysis and powder X-ray diffraction study of the reaction product respectively indicate that total Na/Li exchange takes place and the Ti–O framework of the Na2Ti6O13 parent structure is kept under those experimental conditions. Therefore, Li2Ti6O13 has been obtained with the mentioned parent structure. An important change is that particle size is decreased significantly which is favoring lithium insertion. Electrochemical study shows that Li2Ti6O13 inserts ca. 5 Li per formula unit in the voltage range 1.5–1.0V vs. Li+/Li, yielding a specific discharge capacity of 250mAhg−1 under equilibrium conditions. Insertion occurs at an average equilibrium voltage of 1.5V which is observed for oxides and titanates where Ti(IV)/Ti(III) is the active redox couple. However, a capacity loss of ca. 30% is observed due to a phase transformation occurring during the first discharge. After the first redox cycle a high reversible capacity is obtained (ca. 160mAhg−1 at C/12) and retained upon cycling. Taking into consideration these results, we propose Li2Ti6O13 as an interesting material to be further investigated as the anode of lithium ion batteries. [ABSTRACT FROM AUTHOR]

Abstract: The α-polymorph of Li3FeF6 has been obtained at room temperature by a precipitation reaction from aqueous solution. This easy procedure that does not require any further annealing at high temperature yields a white powder with particles sizes ranging from 250 to 400nm. After proper processing by mechanical milling, particle sizes clearly below 100nm are achieved and this fluoride reacts reversibly with lithium at an average voltage of 3.1V, which is expected for the Fe3+/Fe2+ redox couple. After 12h of ball milling observed average particle size is ca. 50nm and a reversible capacity of 100mAhg−1 is obtained. This corresponds to 70% of the theoretical capacity expected for the one electron reduction of Fe3+. The mentioned capacity is fairly kept upon cycling making the new material useful as the positive electrode in lithium batteries. This is the very first time that a material for cathode application in lithium batteries is prepared at room temperature and from aqueous solution, a procedure which is easily scalable and hence of high industrial interest. [Copyright &y& Elsevier]

Abstract: A structural and electrical characterization of the system NiNb2− x Ta x O6 (0≤x≤2) is presented. For x≤0.25 materials with the columbite-type structure typical of NiNb2O6 have been obtained whereas for x≥1 tri-rutile-like oxides were obtained. The electrical properties are similar in both cases; they are semiconducting with very low electrical conductivity and very high activation energy, though slight differences were found as a function of Ta content. Improvement of conductivity by reducing the stoichiometric materials could not be achieved due to decomposition. In this connection, partial substitution of Nb or Ta by Ti has been carried out in order to create oxygen vacancies. Tantalum was partially replaced by Ti to a significant extent in the tri-rutile structure inducing a slight increasing of conductivity. However, for the columbite case neither Nb nor Ta could be partially replaced. This behavior is quite different from that reported for other similar columbites such as MnNb2O6− δ , which exhibits high electrical conductivity upon substitution of niobium by titanium. [Copyright &y& Elsevier]

Abstract: We present an electrochemical study of BiSbO4, an opened layered oxide having a structure related to Aurivillius phases. Li//BiSbO4 cells show a large specific capacity as high as 1250mAhg−1 during reduction down to 0.5V. This reaction involves 18Li atoms per formula unit, pointing it towards a very promising cathode material for primary lithium batteries, in particular for ICD devices. The characterization of the reduction products indicates that the reduction of BiSbO4 with lithium presumably goes along firstly with the formation of metallic Sb and Bi to follow the formation of the alloys Li3Bi and Li3Sb dispersed in a lithium oxide matrix. In situ X-ray diffraction experiments proved the amorphous nature of both metals and final alloys. On the other hand when Li//BiSbO4 cells are limited to discharge down to 1.2V, BiSbO4 reacts with 5Li atoms. After the first discharge, that develops a specific capacity of 350mAhg−1, high cyclability has been observed. [Copyright &y& Elsevier]

Abstract: Structural evolution during topotactical electrochemical lithium insertion and deinsertion reactions in ramsdellite-like Li x Ti2O4 has been followed by means of in situ X-ray diffraction techniques. The starting Li x Ti2O4 (x =1) exists as a single phase with variable composition which extends in the range 0.50≤ x ≤1.33. However, beyond the lower and upper compositional limits, two other single phases, with ramsdellite-like structure, are detected. The composition of these single phases are: TiO2 upon lithium deinsertion and Li2Ti2O4 upon lithium insertion. Both TiO2 and Li2Ti2O4 are characterized by narrow compositional ranges. The close structural relationship between pristine LiTi2O4 and the inserted and deinserted compounds together with the relative small volume change over the whole insertion–deinsertion range (not more than 1.1% upon reduction) is a guaranty for the high capacity retention after long cycling in lithium batteries. The small changes in cell parameters well reflect the remarkable flexibility of the ramsdellite framework against lithiation and delithiation reactions. [Copyright &y& Elsevier]

Abstract: We describe the synthesis, crystal structure, magnetic and electrochemical characterization of new rock salt-related oxides of formula, Li3 M 2RuO6 (M=Co, Ni). The M=Co oxide adopts the LiCoO2 (R-3m) structure, where sheets of LiO6 and (Co2/Ru)O6 octahedra are alternately stacked along the c-direction. The M=Ni oxide also adopts a similar layered structure related to Li2TiO3, where partial mixing of Li and Ni/Ru atoms lowers the symmetry to monoclinic (C2/c). Magnetic susceptibility measurements reveal that in Li3Co2RuO6, the oxidation states of transition metal ions are Co3+ (S=0), Co2+ (S=1/2) and Ru4+ (S=1), all of them in low-spin configuration and at 10K, the material orders antiferromagnetically. Analogous Li3Ni2RuO6 presents a ferrimagnetic behavior with a Curie temperature of 100K. The differences in the magnetic behavior have been explained in terms of differences in the crystal structure. Electrochemical studies correlate well with both magnetic properties and crystal structure. Li-transition metal intermixing may be at the origin of the more impeded oxidation of Li3Ni2RuO6 when compared to Li3Co2RuO6. Interestingly high first charge capacities (between ca. 160 and 180mAhg−1) corresponding to ca. 2/3 of theoretical capacity are reached albeit, in both cases, capacity retention and cyclability are not satisfactory enough to consider these materials as alternatives to LiCoO2. [Copyright &y& Elsevier]

The development of sustainable, safe, low-cost, high energy and density power-density energy storage devices is most needed to electrify our modern needs to reach a carbon-neutral society by ~2050. Batteries are the backbones of future sustainable energy sources for both stationary off-grid and mobile plug-in electric vehicle applications. Biomass-derived carbon materials are extensively researched as efficient and sustainable electrode/anode candidates for lithium/sodium-ion chemistries due to their well-developed tailored textures (closed pores and defects) and large microcrystalline interlayer spacing and therefore opens-up their potential applications in sustainable potassium and aluminum batteries. The main purpose of this perspective is to brief the use of biomass residues for the preparation of carbon electrodes for potassium and aluminum batteries annexed to the biomass-derived carbon physicochemical structures and their aligned electrochemical properties. In addition, we presented an outlook as well as some challenges faced in this promising area of research. We believe that this review enlightens the readers with useful insights and a reasonable understanding of issues and challenges faced in the preparation, physicochemical properties and application of biomass-derived carbon materials as anodes and cathode candidates for potassium and aluminum batteries, respectively. In addition, this review can further help material scientists to seek out novel electrode materials from different types of biomasses, which opens up new avenues in the fabrication/development of next-generation sustainable and high-energy density batteries.

The present work elucidates facile one-pot synthesis from biomass forestry waste (Norway spruce bark) and its chemical activation yielding high specific surface area ( S BET ) biochars as efficient lithium- and sodium-ion storage anodes. The chemically activated biochar using ZnCl 2 (Biochar-1) produced a highly mesoporous carbon containing 96.1% mesopores in its structure as compared to only 56.1% mesoporosity from KOH-activated biochars (Biochar-2). The latter exhibited a lower degree of graphitization with disordered and defective carbon structures, while the former presented more formation of ordered graphite sheets in its structure as analyzed from Raman spectra. In addition, both biochars presented a high degree of functionalities on their surfaces but Biochar-1 presented a pyridinic-nitrogen group, which helps improve its electrochemical response. When tested electrochemically, Biochar-1 showed an excellent rate capability and the longest capacity retentions of 370 mA h g -1 at 100 mA g -1 (100 cycles), 332.4 mA h g -1 at 500 mA g -1 (1000 cycles), and 319 mA h g -1 at 1000 mA g -1 after 5000 cycles, rendering as an alternative biomass anode for lithium-ion batteries (LIBs). Moreover, as a negative electrode in sodium-ion batteries, Biochar-1 delivered discharge capacities of 147.7 mA h g -1 at 50 mA g -1 (140 cycles) and 126 mA h g -1 at 100 mA g -1 after 440 cycles., Competing Interests: The authors declare no competing financial interest., (© 2022 The Authors. Published by American Chemical Society.)

Aims: The pharmacokinetic (PK) similarity between MB02, a proposed bevacizumab biosimilar, and reference bevacizumab approved from the USA (US-bevacizumab) and European Union (EU-bevacizumab) was evaluated. Safety and immunogenicity were also assessed., Methods: In this phase 1, randomized, double blind, single dose, parallel group study, 114 healthy male volunteers were randomized 1:1:1 to receive a 3 mg/kg intravenous dose of MB02, US-bevacizumab or EU-bevacizumab, and evaluated for 100 days. PK similarity between MB02 and reference bevacizumab was determined using the standard bioequivalence criteria (0.80-1.25) for the area under the serum concentration-time curve from time 0 extrapolated to infinity (AUC (0-∞) ) and the maximum observed serum concentration (C max )., Results: Baseline demographics were similar across treatment groups. All study drugs exhibited similar PK profile. The 90% confidence interval for the geometric lead square means ratios for the primary parameters AUC (0-∞) and C max for MB02, US-bevacizumab and EU-bevacizumab were fully contained within the pre-defined bioequivalence limits for the 3 pairwise comparisons: AUC (0-∞) (MB02:US-bevacizumab 0.998 [0.944 to 1.05]; MB02:EU-bevacizumab 1.07 [1.00 to 1.14]; and US-bevacizumab:EU-bevacizumab 0.934 [0.884 to 0.988]) and C max (MB02:US-bevacizumab 0.983 [0.897 to 1.08]; MB02:EU-bevacizumab 1.06 [0.976 to 1.16]; and; US-bevacizumab: EU-bevacizumab 0.926 [0.851 to 1.01]). Treatment emergent adverse events were reported in 87 subjects (76.3%), most being mild and with comparable incidence among treatment groups. Thirty-three subjects (28.9%) reported 56 possibly related treatment emergent adverse events with comparable incidence across treatments, the most frequent being headache (10.5%) and fatigue (3.5%). Anti-drug antibody incidence was low and similar between treatment groups., Conclusions: This study demonstrates the PK similarity and bioequivalence of MB02 to the reference bevacizumab, whether approved from USA or EU. The safety and immunogenicity profile of MB02 was shown also to be similar to the bevacizumab reference product (NCT04238663)., (© 2021 The Authors. British Journal of Clinical Pharmacology published by John Wiley & Sons Ltd on behalf of British Pharmacological Society.)

The electrode performance and degradation of 1:1 La 2-x NiTiO 6- δ :YSZ composites (x = 0, 0.2) has been investigated to evaluate their potential use as SOFC cathode materials by combining electrochemical impedance spectroscopy in symmetrical cell configuration under ambient air at 1173 K, XRD, electron microscopy and image processing studies. The polarisation resistance values increase notably, i.e., 0.035 and 0.058 Ωcm 2 h -1 for x = 0 and 0.2 samples, respectively, after 300 h under these demanding conditions. Comparing the XRD patterns of the initial samples and after long-term exposure to high temperature, the perovskite structure is retained, although La 2 Zr 2 O 7 and NiO appear as secondary phases accompanied by peak broadening, suggesting amorphization or reduction of the crystalline domains. SEM and TEM studies confirm the ex-solution of NiO with time in both phases and also prove these phases are prone to disorder. From these results, degradation in La 2-x NiTiO 6- δ :YSZ electrodes is due to the formation of La 2 Zr 2 O 7 at the electrode-electrolyte interface and the ex-solution of NiO, which in turn results in the progressive structural amorphization of La 18 NiTiO 6- δ phases. Both secondary phases constitute a non-conductive physical barrier that would hinder the ionic diffusion at the La 2-x NiTiO 6- δ :YSZ interface and oxygen access to surface active area.

The organic solvents that are widely used as electrolytes in lithium ion batteries present safety challenges due to their volatile and flammable nature. The replacement of liquid organic electrolytes by non-volatile and intrinsically safe ceramic solid electrolytes is an effective approach to address the safety issue. However, the high total resistance (bulk and grain boundary) of such compounds, especially at low temperatures, makes those solid electrolyte systems unpractical for many applications where high power and low temperature performance are required. The addition of small quantities of a polymer is an efficient and low cost approach to reduce the grain boundary resistance of inorganic solid electrolytes. Therefore, in this work, we study the ionic conductivity of different composites based on non-sintered lithium lanthanum titanium oxide (La 0.5 Li 0.5 TiO 3 ) as inorganic ceramic material and organic polymers with different characteristics, added in low percentage (<15 wt.%). The proposed cheap composite solid electrolytes double the ionic conductivity of the less cost-effective sintered La 0.5 Li 0.5 TiO 3 .