On the strange case of divalent ions intercalation in V2O5

International audienceVanadium pentoxide has been investigated for multivalent ion battery technologies but the structural characterization of inserted phases is poor, and conflicting reports exist in the literature. This study presents a critical overview of controversial aspects related to Mg and Ca insertion in α-V2O5 under diverse conditions by combined electrochemical and ex-situ XRD experiments. Galvanostatic tests are carried out in dry and wet alkyl carbonate-based electrolytes at RT and 100 °C. The formation of protonated phases with negligible divalent ion content if any is evidenced by Rietveld refinements of the XRD data, unambiguously dismissing the presence of AV2O5 (A: Mg, Ca) as electrochemical reduction products. Furthermore, thermal instability of V2O5 at 100 °C in alkyl carbonate solvents is demonstrated by XRD and TEM analysis and the formation of an orthorhombic phase with increased a parameter, most likely due to degradation favored by both water and temperature, is observed for both Mg and Ca. In order to assess the feasibility of the reverse reaction, fully intercalated AV2O5 (A = Ca, Mg) phases were also prepared by solid state reaction and oxidation attempted both electrochemically and chemically without evidence of any significant amount of Mg2+ or Ca2+ extraction, further corroborating the sluggish diffusion kinetics of divalent cations in α-V2O5

High capacity tin-iron oxide-carbon nanostructured anode for advanced lithium ion battery

A novel nanostructured SneFe2O3eC anode material, prepared by high-energy ball milling, is here originally presented. The anode benefits from a unique morphology consisting in Fe2O3 and Sn active nanoparticles embedded in a conductive buffer carbon matrix of micrometric size. Furthermore, the Sn metal particles, revealed as amorphous according to X-ray diffraction measurement, show a size lower than 10 nm by transmission electron microscopy. The optimal combination of nano-scale active materials and micrometric electrode configuration of the SneFe2O3eC anode reflects into remarkable electrochemical performances in lithium cell, with specific capacity content higher than 900 mAh g-1 at 1C rate (810 mA g -1) and coulombic efficiency approaching 100% for 100 cycles. The anode, based on a combination of lithium conversion, alloying and intercalation reactions, exhibits exceptional rate-capability, stably delivering more than 400 mAh g-1 at the very high current density of 4 A g-1. In order to fully confirm the suitability of the developed SneFe2O3eC material as anode for lithium ion battery, the electrode is preliminarily studied in combination with a high voltage LiNi0.5Mn1.5O4 cathode in a full cell stably and efficiently operating with a 3.7 V working voltage and a capacity exceeding 100 mAh g-1

High capacity tin-iron oxide-carbon nanostructured anode for advanced lithium ion battery

A novel nanostructured SneFe2O3eC anode material, prepared by high-energy ball milling, is here originally presented. The anode benefits from a unique morphology consisting in Fe2O3 and Sn active nanoparticles embedded in a conductive buffer carbon matrix of micrometric size. Furthermore, the Sn metal particles, revealed as amorphous according to X-ray diffraction measurement, show a size lower than 10 nm by transmission electron microscopy. The optimal combination of nano-scale active materials and micrometric electrode configuration of the SneFe2O3eC anode reflects into remarkable electrochemical performances in lithium cell, with specific capacity content higher than 900 mAh g-1 at 1C rate (810 mA g -1) and coulombic efficiency approaching 100% for 100 cycles. The anode, based on a combination of lithium conversion, alloying and intercalation reactions, exhibits exceptional rate-capability, stably delivering more than 400 mAh g-1 at the very high current density of 4 A g-1. In order to fully confirm the suitability of the developed SneFe2O3eC material as anode for lithium ion battery, the electrode is preliminarily studied in combination with a high voltage LiNi0.5Mn1.5O4 cathode in a full cell stably and efficiently operating with a 3.7 V working voltage and a capacity exceeding 100 mAh g-1

High-Capacity NiO-(Mesocarbon Microbeads) Conversion Anode for Lithium-Ion Battery

A conversion-type, NiO–MCMB (mesocarbon microbeads) composite anode prepared by high-energy ball milling is here characterized and tested in lithium half and full cells. An optimized and submicrometric morphology allows the NiO–MCMB electrode to achieve high cell performance and excellent rate capability, that is, delivering specific capacities of 515 and 450 mAhg -1 when cycled at current densities as high as 545 and 1090 mAg -1, respectively. The NiO–MCMB composite anode is studied in a full lithium-ion battery using a high-voltage LiNi0.5Mn1.5O4 electrode that is considered a suitable cathode in combination with conversion-type electrodes. The battery delivers a specific capacity of 90 mAhg -1 with high coulombic efficiency and an average working voltage of 4.1 V. The electrochemical results suggest the viability of the alternative cell configuration here adopted for the development of low cost, high-energy-density lithium-ion batteries

Transition metal oxide-carbon composites as conversion anodes for sodium-ion battery

Herein, we characterize various metal oxide-carbon composites, i.e. CuO-MCMB (mesocarbon microbeads), Fe2O3–MCMB and NiO-MCMB, as anode materials for application in sodium-ion battery. The electrodes, supposed to react through a conversion mechanism, are studied in terms of structure, morphology and electrochemical behavior in sodium cell. The results demonstrate a specific capacity of the order of 100 mAh g-1 for Fe2O3–MCMB and NiO-MCMB, and of about 300 mAh g-1 for CuO-MCMB. The remarkable performance of the latter suggests the copper oxide-based electrode as the preferred anode material for battery application. Indeed, further study aimed to clarify the Na/CuO-MCMB reaction mechanism is performed by ex-situ X-ray diffraction on electrode material cast onto aluminum support. The study suggests a partial conversion reaction for CuO-based anode that is considered suitable candidate in replacement of sodium metal, in efficient and safe Na-ion battery

Transition metal oxide-carbon composites as conversion anodes for sodium-ion battery

Herein, we characterize various metal oxide-carbon composites, i.e. CuO-MCMB (mesocarbon microbeads), Fe2O3-MCMB and NiO-MCMB, as anode materials for application in sodium-ion battery. The electrodes, supposed to react through a conversion mechanism, are studied in terms of structure, morphology and electrochemical behavior in sodium cell. The results demonstrate a specific capacity of the order of 100 mAh g-1 for Fe2O3-MCMB and NiO-MCMB, and of about 300 mAh g-1 for CuO-MCMB. The remarkable performance of the latter suggests the copper oxide-based electrode as the preferred anode material for battery application. Indeed, further study aimed to clarify the Na/CuO-MCMB reaction mechanism is performed by ex-situ X-ray diffraction on electrode material cast onto aluminum support. The study suggests a partial conversion reaction for CuO-based anode that is considered suitable candidate in replacement of sodium metal, in efficient and safe Na-ion battery

New lithium ion batteries exploiting conversion/alloying anode and LiFe0.25Mn0.5Co0.25PO4 olivine cathode

New Li-ion cells are formed by combining a LiFe0.25Mn0.5Co0.25PO4 olivine cathode either with Sn-Fe2O3-C or with Sn-C composite anodes. These active materials exhibit electrochemical properties very attractive in view of practical use, including the higher working voltage of the LiFe0.25Mn0.5Co0.25PO4 cathode with respect to conventional LiFePO4, as well as the remarkable capacity and rate capability of Sn-Fe2O3-C and Sn-C anodes. The stable electrode/electrolyte interfaces, demonstrated by electrochemical impedance spectroscopy, along with proper mass balancing and anode pre-lithiation, allow stable galvanostatic cycling of the full cells. The two batteries, namely Sn-Fe2O3-C/LiFe0.25Mn0.5Co0.25PO4 and Sn-C/LiFe0.25Mn0.5Co0.25PO4, reversibly operate revealing promising electrochemical features in terms of delivered capacity, working voltage and stability, thus suggesting these electrodes combinations as suitable alternatives for an efficient energy storage

Lithium-ion batteries for sustainable energy storage: Recent advances towards new cell configurations

The recent advances in the lithium-ion battery concept towards the development of sustainable energy storage systems are herein presented. The study reports on new lithium-ion cells developed over the last few years with the aim of improving the performance and sustainability of electrochemical energy storage. Alternative chemistries involving anode, cathode and electrolyte components are herein recalled in order to provide an overview of state-of-the-art lithium-ion battery systems, with particular focus on the cell configurations currently proposed at the laboratory scale. Hence, the review highlights the main issues related to full cell assembly, which have been tentatively addressed by a limited number of reports, while many papers describe materials investigation in half-cells, i.e., employing lithium metal anodes. The new battery prototypes here described are evaluated in terms of their electrochemical performances, cell balance, efficiency and cycle life. Finally, the applicability of these suitable energy storage systems is evaluated in the light of their most promising characteristics, thus outlining a conceivable scenario for new generation, sustainable lithium-ion batteries

Electrochemical and structural evaluation of TiS2 as cathode material for calcium rechargable batteries

The experimental details on the data acquisition and data treatment are available at the article with DOI 10.1149/1945-7111/ab7a82This research was conducted under the innovation program H2020 FETOPEN-1-2016-2017 (CARBAT, grant agreement no. 766617). The objective of the CARBAT project is the development of a calcium metal rechargeable battery. This work aims to establish a reliable was to evaluate cathode active material for calcium reversible intercalation and shows the potential use of TiS2 as reversible cathode material for calcium batteries at room temperature.This dataset includes the electrochemical curves corresponding to a TiS2 cell cycled in 0.3 M Ca(TFSI)2 in PC electrolyte solution and tested at C/50 rate and at 60 °C. as well as x-ray diffraction data and the corresponding rietvel refinment pcr file of the reduced electrode samples.Peer reviewe

Electrochemical Study of a CuO–Carbon Conversion Anode in Ionic Liquid Electrolyte for Application in Li-Ion Batteries

A CuO–Carbon anode storing lithium through a conversion mechanism is electrochemically studied in cells employing Pyr14TFSI–LiTFSI electrolyte [Pyr14: N-butyl-N-methylpyrrolidinium], [TFSI: bis(trifluoromethanesulfonyl) imide]. The electrode delivers a specific capacity as high as 580 mAh g−1with a coulombic efficiency exceeding 98 %. The combination of CuO–carbon with a high-voltage LiNi0.5Mn1.5O4cathode in the ionic liquid electrolyte produces a Li-ion battery with an average operating voltage of 3 V and specific capacity of approximately 120 mAh g−1. The cell, employing easily-prepared electrodes and a safe ionic liquid electrolyte, represents a good candidate for use in sustainable power sources