No description available.

This thesis concerns the use of advanced solid-state NMR methods to investigate local structural features and ion dynamics in a series of paramagnetic cathode materials for lithium and sodium ion batteries. A variety of polyanionic phosphate and fluorophosphate derivatives were explored to identify characteristics that ultimately improve battery performance. Solid-state NMR is an excellent method to probe such materials, as it offers the unique ability to track the charge-carrying alkali ion (Li or Na) over the course of the electrochemical process, adding insight not obtainable by bulk characterization techniques. Selective inversion exchange experiments were used to elucidate ion diffusion pathways in low-mobility Li ion conductors Li2MnP2O7 and Li2SnO3. Contrasting experimental results highlight significant differences observed when the method is applied to paramagnetic versus diamagnetic systems, with the former being much more complicated to study with traditional exchange spectroscopy methods. Selective inversion was similarly applied to a new lithium iron vanadate framework, LiFeV2O7, where the changing ion dynamics as a function of electrochemical state of charge were quantified, allowing for the development of a model to explain the corresponding phase changes in the material. This represents the first example of an ex situ Li-Li exchange study for a cathode material, particularly where the conductivity changes are linked directly to a change of ion exchange rates. Additionally, 23Na NMR spectroscopy was additionally used to investigate Na2FePO4F as a potential Na ion battery cathode, where ex situ NMR measurements successfully determined the local Na ion distribution in the electrode as a function of electrochemical cycling. In combination with density functional theory (DFT) calculations, the NMR results lead to the construction of a biphasic desodiation model for Na2FePO4F cathodes. Finally, possible defect formation in sodium iron fluorophosphate was investigated with a variety of methods including 23Na NMR, DFT calculations, powder X-ray diffraction and Mössbauer spectroscopy. / Thesis / Doctor of Philosophy (PhD) / Lithium ion batteries are considered to be at the forefront of current energy storage development, offering high energy density in a small and lightweight package. This thesis delineates the investigation of materials for both lithium and sodium ion batteries via nuclear magnetic resonance methods. Slow Li ion dynamics were investigated and quantified in three lithium-conducting materials: Li2MnP2O7, Li2SnO3, and LiFeV2O7 via the use of selective inversion NMR experiments. In the case of the latter, the ion dynamics were probed ex situ during the course of battery cycling, where a maximum in Li mobility is observed approximately half way through the charge-discharge cycle. Additionally, a potential Na ion cathode material, Na2FePO4F, was found by ex situ methods to reveal a biphasic mechanism for the desodiation of the electrode during charging. This mechanism and the NMR data used to discover it were further supported by ab initio calculations.

The demand for alternative secondary batteries to lithium-ion batteries (LIBs) grows. Sodium-ion batteries (SIBs) have been studied for many years and could replace LIBsfor some application. Metallic anodes for both LIBs and SIBs are interesting due totheir high energy densities. Several aspects such as reactivity, stability and depositionmorphology must be properly addressed before metallic Na could be considered apossible anode material. This study aims to evaluate deposition of Na on Alelectrodes using fundamental electrochemical theories. Na deposition was studiedusing pouch cells and sodium triflate (NaOTf) in dimethyl glycol ether (diglyme) aselectrolyte. Galvanostatic deposition using different current densities, electrolyteconcentrations and potential pulses prior to galvanostatic deposition were tested. Theelectrochemical methods used in this study were galvanostatic deposition andchronoamperometry. The morphology of deposited Na was analyzed with ex-situscanning electron microscopy (SEM). A decrease of the size of deposited Na islandswas observed for both increasing current density and decreasing electrolyteconcentration. Fluctuations and poor stability in the deposition potential wereobtained when decreasing the electrolyte concentration under 0.5 M and also whenincreasing the current density over 1 mA cm-2. The most homogeneous depositionwas obtained with a 1030 ms potential pulse amplitude (-3 V vs. Na+/Na) prior togalvanostatic deposition (1 mA cm-2, 0.5 mAh cm-2) using 0.1 M NaOTf in diglyme aselectrolyte. Reproducibility was a major issue in this study and further investigation ofseveral parameters is needed.

L'évolution des consommations énergétiques au cours des dernières décennies entraîne des modifications majeures dans la conception des systèmes électriques autonomes à fournir, que ce soit pour des applications électriques ou électroniques. La nécessité présente de réaliser des générateurs capables de délivrer l'énergie suffisante, avec une garantie de sûreté maximale, impose à la recherche l'exploration de nouvelles voies de stockage. Les voies actuelles par accumulateurs au lithium tendent à montrer leurs limites, tant stratégiques qu'environnementales. Dans ce cadre, la construction de nouveaux systèmes électrochimiques mettant en œuvre le sodium ouvre une possibilité de réalisation d'accumulateurs sans lithium. Le besoin de batteries toujours plus performantes oblige à des conceptions innovantes, abandonnant la voie liquide au profit de systèmes tout solide plus sécuritaires. De plus, la miniaturisation de l'électronique conduit à revoir le dimensionnement des batteries, vers des batteries de type micro, pour lesquelles l'intérêt d'un empilement tout solide n'est plus à démontrer. Aujourd'hui, des verres de chalcogénures au soufre permettent l'accès à des conductivités ioniques qui laissent entrevoir la possibilité d'une réalisation de batteries tout solide, à la fois sous forme de micro batteries ou de batteries massives. Un effort de recherche a été porté à la formulation de ces verres de chalcogénures afin d'obtenir des conductivités ioniques maximales et des propriétés autorisant leur utilisation comme électrolyte. La modification de ces verres met alors en lumière l'intérêt des différents éléments les composant. L'étude de la mise en forme de l'électrolyte par dépôts de type couches minces (obtenues par Radio Fréquence Magnétron Sputering, RFMS) prouve la faisabilité de ces micro batteries tout solide au sodium. Par la suite, la réalisation de batteries massives tout solide a demandé la synthèse de deux matériaux de cathode (NaCrO2 et Na[Ni0,25Fe0,5Mn0,25]O2) et de deux matériaux d'anode (Na15Sn4 et Na) permettant ainsi la mise en œuvre de quatre empilements électrochimiques, tous caractérisés comme accumulateurs. Enfin, l'amélioration des interfaces grâce à un gel-polymère a permis de perfectionner les propriétés des assemblages avec notamment une augmentation des vitesses de charge/décharge et une mobilisation accrue des matériaux actifs de cathode. / The evolution of energy consumption in recent decades has led to major changes in the design of autonomous electrical systems dedicated to either electrical or electronic applications. The present demand to build generators capable of delivering sufficient energy, with a guarantee of maximum safety, requires to explore new storage routes. The current lithium battery routes tend to show their limits, both strategic and environmental. In this context, the construction of new electrochemical systems implementing sodium opens the way of the lithium-free accumulators production. The need for ever more efficient batteries requires innovative designs, giving up the liquid path in favor of stronger solid systems. In addition, the miniaturization of electronics leads to a review of the size of the batteries, to micro-type batteries, for which the interest of a solid stack is no longer to demonstrate. Today, sulfur chalcogenide glasses allow access to ionic conductivities that suggest the possibility of a realization of all solid batteries, both in the form of micro batteries or massive batteries. A research effort has been made to formulate these chalcogenide glasses in order to obtain a maximum of ionic conductivity and properties allowing their use as electrolytes. The composition of these glasses highlights the interest of the different elements for such properties. The study of the electrolyte shaping by thin-film deposition (obtained by Radio Frequency Magnetron Sputering, RFMS) proves the feasibility of these all-solid sodium micro-batteries. Subsequently, the realization of massive all solid batteries required the synthesis of two cathode materials (NaCrO2 and Na [Ni0.25Fe0.5Mn0.25]O2) and two anode materials (Na15Sn4 and Na) thus allowing the implementation of four electrochemical stacks, all characterized as accumulators. Finally, the improvement of the interfaces thanks to a gel-polymer made it possible to improve the properties of the assemblies with notably an increase of the speeds of charge / discharge and an enhanced mobilization of the cathode active materials.

The aim of this project was to find a recycling route for Prussian white. During the experimental part, one recycling method was tested using sodium hydroxide and from this a method for re-synthesis of Prussian white was conducted as well as a method for re-crystallisation of sodium ferrocyanide. The method that proved most successful was the re-crystallisation of sodium ferrocyanide. Furthermore, the conditions needed to conduct a proper re-synthesis of Prussian white was not available during this research. Therefore, it was not possible to produce Prussian white of the right structure. The analysis was performed through XRD analysis and it was concluded that it is possible to re-crystallise sodium ferrocyanide from Prussian white.

Hard carbon is regarded as one of the most promising anode materials for sodium-ion battery. However, the ash content of the hard carbon anode inherited from the precursor have several negative impacts on the electrochemical performance of hard carbon. The traditional method utilizes strong inorganic acid washing to reduce the ash content of hard carbon. However, this method results in heavy environment pressure and safety hazards. Therefore, it’s necessary to exploring an alternative ash content removal method which is safer and environment friendly. This project develops an environmentally friendly approach to remove ash from hard carbon by using acetic acid. This approach effectively reduces the ash content and enhances the electrochemical performance of the hard carbon anode. The ash content of hard carbon decrease from 1.57 wt% to 0.655 wt% after the 4 mol /L acetic acid treatment. The two-step treatment process also studied in this project and shows a better ash removal ability than one-step treatment process. The ash content of 4 mol /L acetic acid and 20 wt% KOH only 0.28 wt%. Furthermore, the electrochemical performance of the two- step treated hard carbon exhibits notable improvements, including enhanced initial Columbic efficiency (from 84.53% to 88.11%), reversible capacity (from 244.2 mAh g-1 to 280.8 mAh g-1). The long cycle performance of chemical treated hard carbon anode need further investigations in future studies. / Hårt kol anses vara ett av de mest lovande anodmaterialen för natriumjonbatterier. Askhalten i den hårda kolanoden som ärvts från prekursorn har dock flera negativa effekter på den elektrokemiska prestandan hos hårt kol. Den traditionella metoden använder stark oorganisk syratvättning för att minska askhalten av hårt kol. Denna metod resulterar dock i hög miljöbelastning och säkerhetsrisker. Därför är det nödvändigt att utforska en alternativ metod för borttagning av askinnehåll som är säkrare och miljövänligare. Detta projekt utvecklar ett miljövänligt tillvägagångssätt för att ta bort aska från hårt kol genom att använda ättiksyra. Detta tillvägagångssätt reducerar effektivt askinnehållet och förbättrar den elektrokemiska prestandan hos den hårda kolanoden. Askhalten i hårt kol minskar från 1,57 viktprocent till 0,655 viktprocent efter 4 mol/L ättiksyrabehandlingen. Tvåstegsbehandlingsprocessen studerades också i detta projekt och visar en bättre förmåga att avlägsna aska än enstegsbehandling. Askhalten av 4 mol/L ättiksyra och 20 viktprocent KOH är endast 0,28 viktprocent. Dessutom uppvisar den elektrokemiska prestandan hos det tvåstegsbehandlade hårda kolet anmärkningsvärda förbättringar, inklusive förbättrad initial Columbic effektivitet (från 84,53 % till 88,11 %), reversibel kapacitet (från 244,2 mAh g-1 till 280,8 mAh g-1). Den långa cykelprestandan hos kemiskt behandlad hård kolanod behöver ytterligare undersökningar i framtida

A new preparation concept of a partially porous solid-state bilayer electrolyte (BE) for high-temperature sodium-ion batteries has been developed. The porous layer provides mechanical strength and is infiltrated with liquid and highly conductive NaAlCl4 salt, while the dense layer prevents short circuits. Both layers consist, at least partially, of Na-β-alumina. The BEs are synthesized by a three-step procedure, including a sol-gel synthesis, the preparation of porous, calcined bulk material, and spin coating to deposit a dense layer. A detailed study is carried out to investigate the effect of polyethylene oxide (PEO) concentration on pore size and crystallization of the bulk material. The microstructure and crystallographic composition are verified for all steps via mercury intrusion, X-ray diffraction, and scanning electron microscopy. The porous bulk material exhibits an unprecedented open porosity for a NaxAlOy bilayer-system of ≤57% with a pore size of ≈200–300 nm and pore volume of ≤0.3 cm3∙g−1. It contains high shares of crystalline α-Al2O3 and Na-β-alumina. The BEs are characterized by impedance spectroscopy, which proved an increase of ionic conductivity with increasing porosity and increasing Na-β-alumina phase content in the bulk material. Ion conductivity of up to 0.10 S∙cm−1 at 300 °C is achieved.

Because of the changing energy supply landscape, with the transition towards renewable energy, an emerging demand for energy storage systems (ESS) is expected in the near future. Battery energy storage is promising to contribute to mitigate the greenhouse gas emissions, but face issues considering resource use (IEA, 2023; IRENA, 2022). Sodium-ion batteries are a promising technology for the ESS-market, expected to take up 21 % of new installations by 2030. This means an anticipated demand of about 50 GWh of sodium-ion cells required in 2030. Key drivers for the expected entrance of sodium-ion storage are the low price, high abundance of cell materials and expectations of a more safe and sustainable battery. Lithium-ion technology is currently dominating the energy storage market, but have concerns with ethical resource supply and rising mineral prices combined with the growing demand. (BloombergNEF, 2023; IEA, 2023) There is a scarcity of information considering sodium-ion environmental reporting (Liu et al., 2021; Peters et al., 2021). Therefore, the purpose of this study is to evaluate the environmental aspect of sodium-ion storage technology. Thereby, with this study a life cycle assessment (LCA) is performed on a specific sodium-ion cell. The specific scope for the thesis is to look at 1 kWh of produced battery energy storage, in a cradle-to-gate perspective. The results are to be presented with a decomposition of the emissions across the value chain including materials, transport, and energy influence. As well a division of the cell materials impacts are demonstrated. For the assessed cell, it is assumed to be intended for a giga scale production (>1 GWh annual cell storage produced). Hypothetically this is to be placed in Europe, with both a global and a local supply chain presented. In order with European initiatives, there is a guideline called PEFCR, that recommends how to access the environmental footprint of different products. Among these guidelines, there is a certain standard for battery environmental assessment, which was pursued to be followed. According to these recommendations, the methodology of this assessment will include 16 environmental perspectives, called EF2.0. The EF2.0 emission categories presented as main result are Climate Change (total), Acidification, Resource Use (fossils), Resource Use (minerals & metals), and Particulate Matter, since these are considered relevant for batteries by PEFCR. (European Commission and ReCharge, 2018) Furthermore, it was chosen for this study to have its core in analysing the EF2.0 Climate Change impact, with the aim to identify measures on how to reduce the carbon footprint caused by the cell’s life cycle. With the perspective of the 16 environmental effects, a sodium-ion current state scenario was put in focus. On top of this, a decarbonized scenario is presented for the EF2.0 Climate Change impact. For the current state scenario, a comparison is made with a lithium-ion cell from industry, produced from fossil-free energy. This is framing the sodium-ion environmental results in the perspective of how a decarbonized lithium-ion cell performs environmentally. Both the sodium and lithium cells included in the comparison, have the aim to be used for energy storage system applications (ESS). Regarding the results for the 16 environmental categories, overall, the cathode is the main driver for emissions, followed by electrolyte and anode. Furthermore, in the decarbonized scenario, it is illustrated that implementing certain measures within the value chain could reduce the sodium-cell carbon emissions with potentially more than half of what is estimated today. Altogether, the sodium-ion value chain is in an emerging expansion phase (Rho motion, 2023), with a young supply chain starting to form. It is discussed that in the near future, with higher energy density on sodium cells commercialized (Peters et al., 2021), the environmental footprint for sodium-ion could significantly improve. Anyhow, the strongest indication from this study, is that the resource use from minerals and metals drastically would reduce with a technology switch from lithium to sodium. Among the 16 environmental impacts as a whole, the main trend is that sodium-ion cells induce less harm on the environment compared to lithium technologies. Certainly, in the future sodium-ion cells could be a low cost and sustainable option available for energy storage systems. / I och med dagens förändrade energiförsörjningslandskap, med en pågående trend mot mer förnybar energi, förväntas en ökad efterfrågan på storskaliga energilagringssystem (ESS) inom en snar framtid. Däribland är batterilagring lovande för att bidra till att minska utsläppen av växthusgaser, men försörjningen av batterier står samtidigt inför utmaningar vad gäller resursutarmning (IEA, 2023; IRENA, 2022). Natriumjonbatterier är en lovande teknik för ESS-marknaden, som förväntas uppta 21 % av försäljningsmarknaden till 2030. Vilket skulle motsvara en efterfrågan på cirka 50 GWh natriumjonceller till 2030. De viktigaste drivkrafterna för en förmodad ökning av natriumbatterilagring är låga kostnader, överflödig tillgång på cellmaterial och förväntningar om att det ska vara ett säkrare och mer hållbart batteri. Litiumbatterier dominerar för närvarande energilagringsmarknaden, men har problem med etisk resursförsörjning och stigande mineralpriser, samtidigt som det finns en växande efterfrågan av energilagring. (BloombergNEF, 2023; IEA, 2023) Eftersom det finns sparsamt med information kring miljökonsekvenser av natriumbatteriproduktion (Liu et al., 2021; Peters et al., 2021) är syftet med den här studien att utvärdera miljöavtrycket av natriumjonbatterilagring. I studien utförs därför en livscykelanalys (LCA) på en bestämd natriumjoncell. Mer specifikt omfattar det att analysera det ekologiska avtrycket av 1 kWh producerad batterikapacitet, i ett cradle-to-gate-perspektiv. Resultaten presenteras dels som en fördelning av utsläppen över hela värdekedjan, inklusive material, transport och produktionspåverkan. Därtill visas en differentiering av cellmaterialets miljöpåverkan. Det berörda batteriet antas vara tillverkad i en giga scale produktion (>1 GWh årlig celltillverkning). Hypotetiskt antas tillverkningen placeras i Europa, men både en global och en lokal leveranskedja bedöms. I enlighet med europeiska initiativ finns det riktlinjer kallade PEFCR, som rekommenderar hur bedömningar av produkters miljöavtryck bör utföras. Det finns en specifik standard för miljöbedömning av batterier, vilken har eftersträvats i den här studien. I enlighet med rekommendationerna, innefattar den här studiens metod att utvärdera 16 miljöperspektiv, kallade EF2.0. De utsläppskategorier (EF2.0) som presenteras som huvudresultat är Climate Change (total), Acidification, Resource Use (fossils), Resource Use (minerals & metals), och Particulate Matter, eftersom dessa enligt PEFCR anses vara relevanta för just batterier. (European Commission and ReCharge, 2018) Det bör understrykas att den här studie har sitt huvudfokus på att analysera EF2.0 Climate Change (total), med målet att identifiera åtgärder för hur koldioxidavtrycket orsakat av batteriets livscykel kan minskas. För de 16 miljökategorierna, har ett natriumbatteris nuvarande läge ”current state scenario” satts i fokus. Utöver det presenteras ett ”decarbonized scenario” för EF2.0 Climate Change (total). För ”current state”-scenariot görs en jämförelse med ett litiumbatteri från industrin, vilket produceras med fossilfri energi. Därmed skapas förståelse för hur natriumbatteriets miljöpåverkan skiljer sig från det lågfossilintensiva litiumjoncellen. Både natrium- och litiumcellerna som ingår i jämförelsen har som avsikt att användas för energilagringssystem (ESS). Gällande resultatet av de 16 miljökategorierna är det tydligt att katoden är den främsta källan för utsläpp, följt av elektrolyten och anoden. I ”decarbonized scenario” illustreras därtill att om vissa specifika åtgärder implementeras i värdekedjan, skulle det kunna minska natriumbatteriers koldioxidutsläpp med potentiellt mer än hälften av vad som uppskattats idag. I nuläget pågår en utveckling och expansion av leveranskedjan för natriumbatteriproduktion (Rho motion, 2023), med en materialproduktion som börjar ta form. Samtidigt kan det i en snart framtid förväntas levereras natriumbatterier med högre energidensitet (Peters et al., 2021) och då skulle miljöpåverkan från natriumceller kunna sjunka avsevärt. Det centrala medskicket från den här studien är att resursanvändningen av mineraler och metaller drastiskt skulle minska i och med ett teknikskifte från litium- till natriumbatterier. Med de 16 miljöperspektiven i åtanke, är det övergripande resultatet att natriumceller orsakar mindre miljöskada jämfört med litiumteknik. Högst troligt, kan natriumceller i framtiden vara ett billigt och hållbart alternativ för energilagringssystem.

Le cœur de technologie d'une batterie réside principalement dans les matériaux actifs des électrodes, qui est fondamental pour pouvoir stocker une grande quantité de charge et garantir une bonne durée de vie. Le dioxyde d'étain (SnO₂) a été étudié en tant que matériau d'anode dans les batteries Li-ion (LIB) et Na-ion (NIB), en raison de sa capacité spécifique élevée et sa bonne tenue en régimes de puissance élevés. Cependant, lors du processus de charge/décharge, ce matériau souffre d'une grande expansion volumique qui entraîne une mauvaise cyclabilité, ce qui empêche la mise en oeuvre de SnO₂ dans des accumulateurs commerciaux. Aussi, pour contourner ces problèmes, des solutions pour surmonter les limites de SnO₂ en tant qu'anode dans LIB / NIB seront présentées dans cette thèse. La partie initiale de la thèse est dédié à la production de SnO₂ et de RGO (oxyde de graphène réduit)/SnO₂ par pyrolyse laser puis à sa mise en oeuvre en tant qu'anode. La deuxième partie s'attarde à étudier l'effet du dopage de l'azote sur les performances et permet de démontrer l'effet positif sur le SnO₂ dans les LIB, mais un effet néfaste sur les NIB. La partie finale de la thèse étudie l'effet de l'ingénierie matricielle à travers la production d'un composé ZnSnO₃. Enfin, les résultats obtenus sont comparés avec l'état de l'art et permettent de mettre en perspectives ces travaux. / The heart of battery technology lies primarily in the electrode material, which is fundamental to how much charge can be stored and how long the battery can be cycled. Tin dioxide (SnO₂) has received tremendous attention as an anode material in both Li-ion (LIB) and Na-ion (NIB) batteries, owing to benefits such as high specific capacity and rate capability. However, large volume expansion accompanying charging/discharging process results in poor cycleability that hinders the utilization of SnO₂ in commercial batteries. To this end, engineering solutions to surmount the limitations facing SnO₂ as an anode in LIB/NIB will be presented in this thesis. The initial part of the thesis focuses on producing SnO₂ and rGO (reduced graphene oxide)/SnO₂ through laser pyrolysis and its application as an anode. The following segment studies the effect of nitrogen doping, where it was found to have a positive effect on SnO₂ in LIB, but a detrimental effect in NIB. The final part of the thesis investigates the effect of matrix engineering through the production of a ZnSnO₃ compound. Finally, the obtained results will be compared and to understand the implications that they may possess.

Les accumulateurs au lithium jouent un rôle important comme source d'alimentation pour les appareils électroniques portables en raison de leur forte capacité gravimétrique et volumétrique et leur haute tension. En outre, la technologie lithium-ion est la mieux placée pour une application à grande échelle, telle que le véhicule électrique, ce qui pose un problème de ressource et à terme, de coût. Une des réponses envisagées sur le plan économique et environnemental est le développement d’accumulateurs sodium-ion. Dans tous les cas, le problème scientifique consiste à proposer des matériaux d’insertion des ions sodium avec un caractère réversible de la réaction électrochimique, et une durée de vie compétitive par rapport aux systèmes au lithium. Le travail présenté se situe dans cet effort de recherche. Les potentialités de matériaux dérivés du pentoxyde de vanadium, de structure 2D, sont étudiées comme composés d’intercalation du sodium: le composé de référence V2O5, le bronze performant dérivé de V2O5 de formule K0,5V2O5, ε’-V2O5, ainsi que le composé au manganèse de type lamellaire : la birnessite sol-gel et sa forme dopée au cobalt. Les relations structure-électrochimie sont élucidées à travers une étude combinant propriétés électrochimiques, diffraction des Rayons X et spectroscopie Raman des matériaux à différents taux d’insertion, en fin de réaction et après cyclages galvanostatiques. De nouvelles phases sont obtenues et des capacités spécifiques comprises entre 100 et 160 mAh/g dans le domaine de potentiel 4V-1V peuvent être obtenues avec parfois une stabilité remarquable comme dans le cas de NaV2O5 et ε’-V2O5 / Since commercialization, Li-ion batteries have been playing an important role as power source for portable electronic devices because of high gravimetric, volumetric capacity and high voltage. Furthermore, the lithium-ion technology is best suited for large-scale application, such as electric vehicles, which poses a resource problem and ultimately cost. On the contrary, sodium is a most abundant element, inexpensive and similarly properties as lithium. In order to solve the problem of lithium raw resource, sodium is proposed as a solution for next generation power source storage. This work investigates the potential derivative vanadium pentoxide materials as sodium intercalation compounds: the V2O5 reference compound, the promizing potassium bronze K0,5V2O5, ε'-V2O5, as well as a lamellar manganese oxide: the sol-gel birnessite and its doped cobalt form. The structure-electrochemistry relationships are clarified through a study combining electrochemical properties, X-ray diffraction and Raman spectroscopy of materials at different insertion rate, end of the reaction and after galvanostatic cycling. New phases are highlighted and specific capacities between 100 and 160 mAh / g in the field of 4V-1V potential can be obtained with sometimes remarkably stable as in the case of NaV2O5 and ε'-V2O5