Electrode For Sodium-ion Batteries Research Articles

Diffusion strengthening of self-assembled graphite oxide membranes for lithium and sodium ion battery electrodes

After self-assembly and thermal reduction at low temperature (350 °C), reduced graphite oxide membranes (RGOM) with few cracks are obtained. The structure leads to low specific capacities of RGOM electrodes in lithium ion battery (LIB) and sodium ion battery (SIB). Molecular dynamic (MD) simulations indicate that damage for intactness of RGOM has positive impact on ions' diffusion of RGOM in LIB and SIB electrolyte. The damage is completed by pressing RGOM on Cu foams in this paper. According to electrochemical tests, the charge storage mechanism of RGOM in LIB and SIB are both obviously affected by ions’ diffusion, and thus the modified RGOM electrodes assisted with Cu foams show more electrochemical active sites, higher initial coulombic efficiency (∼1.29 times improvement for LIB and ∼1.40 times improvement for SIB at a current density of 50 mA g−1) and specific capacities (∼5.3 times improvement for LIB and ∼10 times improvement for SIB at a current density of 1 A g−1), which is meaningful for application of RGOM in LIB and SIB on a large scale.

Multiple hydrogen bonding induced by semi-interpenetrating polymer network binder to enhance the electrochemical performance of sodium-ion batteries electrodes

Molybdenum disulfide (MoS2) serves as an ideal anode for sodium-ion batteries (SIBs), boasting a high theoretical specific capacity and large interlayer spacing. However, the substantial volume change and low conductivity present significant challenges in maintaining the electrochemical stability of the electrode. Herein, a novel semi-interpenetrating polymer network (SIPN) binder (sodium alginate-g-poly (acrylamide-co-2-hydroxyethyl acrylate)-boric acid, SA-PAHB) is synthesized by free radical copolymerization grafting and the multiple hydrogen bonding crosslinking (bond energies spanning from − 33.89 to − 45.49 kcal/mol by theoretical calculations), which can effectively mitigate stress in Na+ deintercalation in MoS2 anodes under the synergy of the unique structure of the SIPN, maintaining electrode stability. Simultaneously, the variable hydrogen bonding crosslinking and abundant –NH2 groups greatly facilitate Na+ diffusion and enhance kinetic performance. Leveraging the advantages of SA-PAHB, the electrochemical performance is significantly enhanced compared to traditional SA and grafted SA-based binders. Specifically, MoS2 anodes using SA-PAHB binder exhibit an initial discharge specific capacity of 772.1 mAh/g at 0.1 A/g and retain 511.2 mAh/g at 0.5 A/g after 200 cycles, with no capacity loss. Additionally, an outstanding rate performance is achieved, delivering 378.5 mAh/g at 10 A/g. For sodium-ion coin full-cells, a discharge specific capacity of 125.2 mAh/g is maintained at 0.5 A/g after 50 cycles.

Influence of Interlayer Cation Ordering on Na+ Transport in P2-Type Electrodesfor Sodium-Ion Batteries

P2-typeNa2/3Ni1/3Mn2/3O2 (PNNMO) has been extensively studied because of itsdesirable electrochemical properties as a positive electrode for sodium ion batteries. PNNMO exhibits intralayer transition metal ordering of Ni and Mn and intralayer Na+/vacancy ordering. The Na+/vacancy ordering is often considered a major impediment to fast Na+ transport and can be affected by the transition metal ordering. We show by neutron/X-ray diffraction and density functional theory (DFT) calculations that Li doping (Na2/3Li0.05Ni1/3Mn2/3O2, LFN5) promotes ABC-type interplanar Ni/Mn ordering without disrupting the Na+/vacancy ordering and creates low-energy Li-Mn coordinated diffusion pathways. A structure model is developed to quantitatively identify both the intralayer cation mixing and interlayer cationic stacking fault densities. Quasielastic neutron scattering reveals that the Na+ diffusivity in LFN5 is enhanced by an order of magnitude over PNNMO, increasing its capacity at high current. Na2/3Ni1/4Mn3/4O2 (NM13) lacks Na+/vacancy ordering but has comparable diffusivity to LFN5. However, NM13 has the smallest capacity at a high current. The high site energy of Mn-Mn coordinated Na compared to Ni-Mn, and higher density of Mn-Mn coordinated Na+ sites in NM13 disrupts the connectivity of low-energy Ni-Mn coordinated diffusion pathways. These results suggest that the interlayer ordering can be tuned through the control of composition, which has an equal or greater impact on Na+ diffusion than the Na+/ vacancy ordering.

(Invited) Evaluation and Characterization of NaCl as an Electrode for Sodium-Ion Batteries

Sodium-ion batteries (SIBs) have attracted considerable attention as a promising alternative for large-scale energy storage due to their remarkable benefits in terms of resource availability and cost-effectiveness. However, there is still a big difference in energy density between SIBs and lithium-ion batteries (LIBs) that are commercially available, which makes it hard to meet the needs of practical applications. The fabrication of high-energy cathodes has become a successful approach for increasing the energy density of SIBs. This often involves using cathodes that can operate in high-voltage regions.Herein, we used table salt (NaCl) as a novel cathode material for SIBs, where this electrochemically inactive NaCl was activated by introducing structural defects that induce a phase transition from B1- to B2-type NaCl. It was demonstrated that B2-NaCl could exhibit a high initial capacity of 260 mAh g−1; however, poor cycle stability with unsatisfactory capacity retention was a major challenge for its practical application. For this, additional Na-vacancies were introduced by controlling the upper limit of the cut-off voltage, which helped to accommodate more sodium ions during the next discharge, resulting in increased capacity. Meanwhile, Cl-ions, which are released during NaCl decomposition at high voltage of 4.5 V, are oxidized to form Cl-based organic species at the active material interfaces, which helps to enhance the cycle stability. XPS, SEM, and TOF-SIMS characterizations helped to understand the crucial role of these Cl-based species in protecting the NaCl electrode from undesired side reactions at high voltage. Additionally, the in-situ XRD and XAS studies investigated the relationship between the degree of electrochemical activation and the structural stability of metallic NaxCl. We believe that this study could help in exploring a novel method for generating low-cost and high-capacity electrode material for future energy-storage devices.

Carbon-Based Materials As Negative Electrodes in Sodium-Ion Batteries

Nowadays effective energy storage, especially batteries, plays a crucial role in technology development. Due to the high abundance and low cost of sodium, sodium-ion batteries are promising substitutes for widely used Li-ion cells. Graphite-based materials are commonly used as a negative electrode in lithium systems. However, sodium ions have a larger ionic radius compared to lithium ones, and also the energy of intercalation of graphite by Na+ is higher than by Li+ [1]. Therefore, it is necessary to use different types of carbon- based materials with greater interlayer spacing, which can be achieved through increased structural disorder. These materials could be obtained through the thermal processing of polymers [2]. Additionally, due to their high porosity, the adsorption of sodium ions is more efficient. All these properties enhance the specific capacity of negative electrodes in sodium- ion systems.As a result of thermal processing, we obtained porous carbon-based materials. The synthesized powder's electrochemical characteristics have been examined using three-electrode Swagelok®-type cells. Slurry-coated electrodes with carbon-based materials were used as the working electrode, while sodium metal was used as the reference electrode and the counter electrode.Sodium-ion systems were investigated in a high-rate test, with a charging current of 1 C and discharge current rates varying from 1 C to 10 C. Even at the highest discharge current rate, the batteries retained a high percentage of the first-cycle specific capacity.The cycle stability of sodium-ion systems was also examined. After 50 cycles of charging/discharging at a current of 1 C, the specific capacity did not decrease significantly as compared to the specific capacity of the first cycle.Furthermore, the cyclic voltammetry behaviour of these systems was also investigated. Although the two signals were not well separated, it was evident that two electrochemical phenomena were present: diffusion of sodium cations in the carbon matrix and sodium adsorption on the carbon surface.The synthesised carbon-based porous materials demonstrated stability during the charging and discharging of sodium-ion batteries. The implementation of these products in sodium-ion technology could be helpful during the process of commercialization of such energy storage systems. Acknowledgements: This work was supported by The Polish National Centre of Science through a research grant 2021/43/D/ST5/01220 entitled “High-voltage sodium-ion batteries based on exfoliated graphite electrodes”.Literature:[1] Y. Liu et al. „Origin of low sodium capacity in graphite and generally weak substrate binding of Na and Mg among alkali and alkaline earth metals”, PNAS USA 113 2016 [2] T. Zhang et al. „Recent Advances in Carbon Anodes for Sodium-Ion Batteries”. Chem. Rec. 22 2022

Microstructure Analysis and Performance Study of Wood Lignin-Derived Carbon Foam Electrode for Sodium-Ion Batteries

Carbon foams (CF) offer a promising avenue for advancing energy storage systems due to their unique structure characterized by interconnected open-cell pores and surface-residing carbon nanofibers [1,2]. This structure provides tunability to the porosity, pore structure and size, which makes them ideal for high-energy dense electrodes for energy storage devices. Lignin-derived foams are particularly noteworthy as they utilize an abundant waste stream from paper products, offering a sustainable alternative to fossil-fuel-derived carbons often used in batteries. CFs can serve as electrodes or hosts for energy storage devices based on porosity, pore structure and size, and degree of graphitization, which significantly influences battery capacity, reversibility, and electrochemical reactions [3]. Utilizing natural CF from kraft lignin not only minimizes impacts compared to fossil-fuel-derived carbon sources [4] but also cuts production costs [2], making them an attractive option for large-scale energy storage systems.In this investigation, we examined lignin-derived CFs with differing porosity and pore structures, carbonized across a temperature range of 800°C to 1300°C. Various characterization techniques corroborated the transition from disordered to ordered carbon structure, escalating the graphitization with the increased carbonization temperatures. Pouch cells are assembled using a standard sodium-based electrolyte. Half-cells demonstrated reversible capacities surpassing 200 mAh/g at C/10, affirming the potential of lignin-derived CF-based Na-ion batteries for large-scale energy storage applications. The performance is studied as a function of CF microstructure, porosity, pore structure and size, particle size, and degree of graphitization for a fundamental understanding of the CF electrode. In conclusion, utilizing sodium and lignin, both abundant and low-cost materials, presents a promising avenue for the energy storage industry on a large scale. REFERENCES [1] F. Xu, Y. Gui, S. Zuo, J. Li, S. Wang, Preparation of lignin-based carbon foam monoliths with high strength and developed micrometer-sized cell/nano-sized porous structures using a self-bubbling method, J Anal Appl Pyrolysis 163 (2022).[2] Q. Yan, R. Arango, J. Li, Z. Cai, Fabrication and characterization of carbon foams using 100% Kraft lignin, Mater Des 201 (2021).[3] X.Y. Cui, Y.J. Wang, H.D. Wu, X.D. Lin, S. Tang, P. Xu, H.G. Liao, M. Sen Zheng, Q.F. Dong, A Carbon Foam with Sodiophilic Surface for Highly Reversible, Ultra-Long Cycle Sodium Metal Anode, Advanced Science 8 (2021).[4] S.F. Schneider, C. Bauer, P. Novák, E.J. Berg, A modeling framework to assess specific energy, costs and environmental impacts of Li-ion and Na-ion batteries, Sustain Energy Fuels 3 (2019) 3061–3070.

Insight into Modulation of Ionic Liquids for Na-Ion Batteries: Cation Modification

Sodium-ion batteries (SIBs) have gained global attention as cost-effective energy storage solutions, thanks to the abundance of sodium resources. Ionic liquid electrolytes (ILs) are increasingly recognized as promising candidates for SIBs due to their advantageous properties, including low volatility, reduced flammability, and high electrochemical stability.[1-3] However, their application in SIBs is hindered by irreversible decomposition during the initial charging of negative electrodes, resulting in low initial Coulombic efficiency. Our recent research suggested that the addition of lithium with high Lewis acidity into ILs weakens the interaction between organic cations and anions, leading to the formation of unprotected cations.[4]In this study, we investigate the interaction properties of ILs based on [C3C1pyrr][FSA]-based ILs ([C3C1pyrr]+= N-methyl-N-propylpyrrolidinium and [FSA]− = bis(fluorosulfonyl)amide) and their effects on the Coulombic efficiency at hard carbon negative electrodes for sodium-ion batteries. Furthermore, we explore the impact of pyrrolidinium cations with ether functional group ([Pyr1,2O1]+; N-methoxyethyl-N-methylpyrrolidinium) on the coordination environment of ions and the interfacial properties with negative electrodes through computational analysis.Our series presentation, titled "Insight into Modulation of Ionic Liquids for Li-ion Batteries: Unprotected Cation", explains the effects of Li concentration on the coordination environment of ionic liquid in lithium systems. Reference [1] K. Matsumoto, J. Hwang, S. Kaushik, C.-Y. Chen, R. Hagiwara, Energy Environ. Sci. 12 (2019) 3247.[2] K. Yoshii, T. Masese, M. Kato, K. Kubota, H. Senoh, M. Shikano, ChemElectroChem 6(2019)3901.[3] M. Watanabe, M. L. Thomas, S. Zhang, K. Ueno, T. Yasuda, K. Dokko, Chem. Rev. 117, (2017), 7190.[4] S. Zhang, S. Wu, J. Hwang, K. Matsumoto, R. Hagiwara, J. Am. Chem. Soc. 146 (2024) 8352-8361.

Operando Dilatometry and Gas Analysis of Na-Hard Carbon Half Cells with Carbonate Electrolytes

Sodium-ions that are dissolved in carbonate-based electrolytes do not intercalate well into graphite. Therefore, alternative anode materials are needed for sodium-ion batteries (SIB). Hard carbon anodes are a promising and widely used negative electrode for SIB, showing reversible gravimetric capacities in the range of 150-350 mAh g-1. [1] Volume changes and parasitic side reactions with the electrolyte are undesirable ageing effects which can happen during cycling and shorten the lifespan of a battery. Operando dilatometry and operando mass spectrometry are useful methods to characterize possible degradation mechanisms.In this work we analyzed the volume changes of hard carbon electrodes in carbonate electrolytes during cycling with operando dilatometry, paying special attention to irreversible volume changes e. g. due to sodium plating. In addition, we carried out operando mass spectrometry to investigate gaseous substances produced due to the parasitic side reactions at the electrodes. Gas chromatography mass spectrometry (GC-MS) reveals the relevant species. The electrolyte consisted of 1M NaPF6 dissolved in EC:DMC (1:1, by weight). All measurements were carried out in specially developed test setups.A relationship between the thickness change and voltage profile was established. The thickness changes can be correlated with the different storage mechanisms in the hard carbon electrodes. Additionally, the cyclic formation of the gaseous degradation products could be observed. A possible correlation between gas evolution and thickness change is discussed.In conclusion, the results of this study contribute to a more detailed understanding of possible degradation mechanisms that occur during cycling of hard carbon anodes in carbonate-based electrolytes. A better understanding of the degradation mechanisms could be used to develop strategies to mitigate the negative influence on battery cycle life.[1] Escher, I.; A. Ferrero, G.; Goktas, M.; Adelhelm, P.; In Situ (Operando) Electrochemical Dilatometry as a Method to Distinguish Charge Storage Mechanisms and Metal Plating Processes for Sodium and Lithium Ions in Hard Carbon Battery Electrodes. Adv Materials Inter 2021, 2100596. DOI: 10.1002/admi.202100596.

(Invited) Heterostructure Engineering in Electrode Materials for Sodium-Ion Batteries

Sodium-ion batteries (SIBs) have stepped into the spotlight as a promising alternative to lithium-ion batteries for large-scale energy storage systems. However, SIB electrode materials, in general, have inferior performance than their lithium counterparts because Na+ is larger and heavier than Li+. Heterostructure engineering is a promising strategy to overcome this intrinsic limitation and achieve practical SIBs. In this talk, I will discuss recent progress in heterostructure engineering of electrode materials and research on how the phase interface influences Na+ storage and transport properties.1,2 Combinations of phases can complement each other’s strengths and mitigate their weaknesses if their interfaces are carefully controlled. Efficient strategies for the design and fabrication of heterostructures (in situ methods) will be discussed, with a focus on the heterostructure formation mechanism. The heterostructure’s influence on Na+ storage and transport properties arises primarily from local distortions of the structure and chemomechanical coupling at the phase interface, which may accelerate ion/electron diffusion, create additional active sites, and bolster structural stability. Finally, our perspectives on the existing challenges, knowledge gaps, and opportunities for the advancement of heterostructure engineering as a means to develop practical, high-performance sodium-ion batteries will be discussed.References E. Gabriel et al., eScience, 3, 100139 (2023) https://www.sciencedirect.com/science/article/pii/S2667141723000642.E. Gabriel, D. Hou, E. Lee, and H. Xiong, Energy Science & Engineering, 10, 1672–1705 (2022) https://onlinelibrary.wiley.com/doi/abs/10.1002/ese3.1128.

Structural, optical and electrochemical properties of a new phosphate-based compounds Na2Mn2−xNixFe(PO4)3 as negative electrode for sodium-ion batteries

Structural, optical and electrochemical properties of a new phosphate-based compounds Na2Mn2−xNixFe(PO4)3 as negative electrode for sodium-ion batteries

Cu@MOF based composite materials: High performance anode electrodes for lithium-ion and sodium-ion batteries

In order to satisfy the increasing demand for energy, it is essential to improve the efficiency of lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs) batteries. Metal selenides (MSes) have a high theoretical specific capacity, can be designed in a variety of ways, conduct electricity well, can change morphology easily, and have a multi-electron reaction mechanism. These characteristics make them very competitive as anode materials for LIBs and SIBs. Herein, we synthesise Cu@MOF and Cu@NH2-MOF as the precursor to prepare Cu1.95Se embedded into porous carbon matrix (Cu1.95Se@PC) and porous-N-doped carbon matrix (Cu1.95Se@NPC) via pyrolysis process of Cu@MOF and Cu@NH2-MOF, respectively. Cu1.95Se@PC and Cu1.95Se@NPC electrodes for half-cell LIBs and SIBs exhibit a high reversible capacity of 313.1, 480.9 (for LIBs), 216.3 and 303.8 (for SIBs) mAhg−1after 1000 cycles at 2 A g−1, respectively. We assess the electrochemical performance of the Cu1.95Se@PC and Cu1.95Se@NPC anodes by integrating them with commercially available LiFePO4 (LFP) into full-cell LIBs. The LFP//Cu1.95Se@PC and LFP//Cu1.95Se@NPC full-cells have discharge capacities of approximately 330 and 293 mAh g−1 at 0.3 A g−1 at the initial cycle. In order to explore the sodium storage mechanism of the Cu1.95Se composites, we conducted an in situ XRD test during the first charge/discharge cycle, considering their favourable cycling and rate performance. Our work provides a promising anode electrode material for both half-cell LIBs and SIBs with high volume utilization and superior electrochemical performances.

Unravelling the electrochemical characteristics and sodium storage mechanism of pistachio shell derived hard carbon as high plateau capacity anodes by operando Raman spectroscopy and full cell demonstration

Hard carbon has emerged as a highly promising material for negative electrode in sodium-ion batteries (SIBs). This study focuses on the synthesis of an anode material through the pyrolysis of Pistachio shells, a commonly available nut waste, at different temperatures ranging from 900° to 1400°C. The material pyrolyzed at 1400 °C exhibits a remarkable reversible discharge capacity of 302 mAhg−1 and plateau capacity of 223 mAhg−1 at a current rate of 10 mAg−1, displaying stable cyclic performance and an impressive 80% capacity retention after 500 cycles at 200 mAg−1. The morphological, structural, and surface chemical characteristics of the cycled hard carbon anode materials were examined through ex-situ FE-SEM, XRD, and XPS analyses. Furthermore, the sodiation and desodiation mechanisms of the synthesized hard carbon were investigated using operando Raman Spectroscopy. The diffusion kinetics parameters were determined by Electrochemical Impedance Spectroscopy (EIS) and CV analyses. This study underscores the potential of Pistachio shells as a promising precursor for the synthesis of carbonaceous anode for SIBs, employing a straightforward one-step pyrolysis process. The excellent electrochemical performance, along with the ease of material sourcing and synthesis, places this nutty waste as a promising, sustainable and clean energy resource option for advancing sodium-ion battery technology.

Rational Design of 3D Hierarchical Fe3S4 for Superior Sodium‐Ion Battery Anode Material

AbstractAmong various transition metal sulfides, iron‐based sulfides have attracted wide attention due to their abundant resources, low cost, and non‐toxicity, showing considerable research value in the field of secondary batteries. Thereinto, Fe3S4 has a high theoretical specific capacity of 785 mAh g−1. However, at present, the research related to Fe3S4 anode for sodium‐ion batteries (SIBs) is still in its infancy, and it also suffers from severe volume expansion and limited preparation. Therefore, to further boost its sodium storage potential, the Fe3S4@rGO composite with hierarchical structure and carbonaceous network is proposed in this study. Beneficial from the ingenious hierarchitectures and flexible graphene coating, the Fe3S4@rGO anode exhibits outstanding sodium storage performance, which can deliver a high capacity of 603 mAh g−1 after 1500 cycles with a superior capacity retention of 98%. The micron flower‐like structure composed of 2D nanosheets can provide sufficient active sites and promote the rapid transport of Na+. Meanwhile, the 3D interconnected graphene carbon network makes a crucial contribution to alleviating volume changes and enhancing electrical conductivity. This work reveals the application potential of Fe3S4 as an anode electrode for SIBs and provides available insights for the development of other electrode materials.

Sulfuric acid treatment to control the microcrystalline structure of starch-based hard carbon for sodium storage

By treating starch with different concentrations of sulfuric acid, we investigated the effect of cross-linked starch-based hard carbon on the performance of sodium-ion batteries (SIBs) at various concentrations. After treatment, the optimal sample exhibits a spherical microstructure, which can provide effective active sites and enhance structural stability, thereby achieving high capacity and long cycle life for SIB electrodes. In subsequent electrochemical tests, after 100 cycles at low current density of 0.1 A g−1, the capacity of H40 remains of 306 mA h g−1. And under the high current density of 1 A g−1, the capacity of H40 can still maintain of 228 mA h g−1, exhibiting a high capacity retention rate of 89 %, which is higher than other samples. This study provides a promising approach for the large-scale production of biomass-derived carbonaceous SIBs anodes.

CVD-Synthesized Titanium Carbide Nanoflowers as High-Performance Anodes for Sodium-Ion Batteries.

Sodium-ion batteries (SIBs) have emerged as promising candidates for energy storage applications due to the abundance and low cost of sodium. However, the larger radius of sodium ions limits their diffusion kinetics within electrode materials and contributes to electrode volume expansion. Here, we successfully synthesized porous titanium carbide (TiC) nanoflowers through chemical vapor deposition (CVD). The TiC nanoflowers exhibit exceptional electrochemical performance as SIB anodes, with their porous structure enhancing the conductivity, mechanical stability, and Na-ion diffusion. The TiC nanoflowers demonstrate a high reversible specific capacity of 73.5 mAh g-1 at 1 A g-1 after 2500 cycles, corresponding to an impressive capacity retention of 80.81%. Additionally, we developed a full sodium-ion cell utilizing TiC nanoflowers as the anode and Na3V2(PO4)3 as the cathode, which demonstrates a substantial reversible capacity and outstanding cycling stability. Our work presents a promising strategy for synthesizing nanostructured TiC materials as anode electrodes for SIBs.

Oxidized Ti3Al(1-x)SnxC2 MAX phases as negative electrode materials for sodium ion batteries

Materials proposed for the negative electrodes in sodium-ion batteries often include oxides capable of reacting with Na+ through intercalation, conversion, or alloying. While these oxides offer high specific capacities, they suffer from poor mechanical stability. A novel approach to address this issue involves designing tailored nanocomposites based on the (Ti/Sn)Ox system, achieved through partial oxidation of tin-containing MAX phase (Ti3Al(1-x)SnxC2, x = 0.4 and 0.7). By employing this strategy, we have developed composite electrodes based on Ti(1-y)SnyO2 and MAX phase, which exhibit remarkable durability, withstanding over 600 cycles in half-cells. These electrodes also demonstrate charge efficiencies higher than 99.8 % and specific capacities comparable to MXenes electrodes. These outstanding electrochemical performances are further validated at the full-cell level when combined with Na0.44MnO2 positive electrodes. The reaction mechanism between the composite and the sodium ion was also studied using in-situ techniques (Raman and XAS) and the contribution of the different components during sodiation and de-sodiation was highlighted.

MnFe Prussian Blue Analogue Open Cages for Sodium-Ion Batteries: Simultaneous Evolution of Structure, Morphology, and Energy Storage Properties.

Prussian blue analogues (PBAs) exhibiting hollow morphologies have garnered considerable attention owing to their remarkable electrochemical properties. In this study, a one-pot strategy is proposed for the synthesis of MnFe PBA open cages. The materials are subsequently employed as cathode electrode in sodium-ion batteries (SIBs). The simultaneous evolution of structure, morphology, and performance during the synthesis process is investigated. The findings reveal substantial structural modifications as the reaction time is prolonged. The manganese content in the samples diminishes considerably, while the potassium content experiences an increase. This compositional variation is accompanied by a significant change in the spin state of the transition metal ions. These structural transformations trigger the occurrence of the Kirkendall effect and Oswald ripening, culminating in a profound alteration of the morphology of MnFe PBA. Moreover, the shifts in spin states give rise to distinct changes in their charge-discharge profiles and redox potentials. Furthermore, an exploration of the formation conditions of the samples and their variations before and after cycling is conducted. This study offers valuable insights into the intricate relationship between the structure, morphology, and electrochemical performance of MnFe PBA, paving the way for further optimizations in this promising class of materials for energy storage applications.

A Facile Method to Transform Pickled Olive Wastes Into Sulfur-Doped Carbon for Sodium-Ion Battery Electrode.

This work provides a novel, low-cost, and effective method to prepare disordered carbon materials for advanced sodium-ion batteries using biomass. A large amount of olive stone waste is yearly produced in the world, and it could be re-used for fine applications other than fuel for heat production. After treatment with sulfuric acid solution and carbonization process, wastes of olive stone are efficiently transformed into optimized carbon electrode material. XRD, XRF and XPS, electron microscopy, and physical gas adsorption are used for the compositional, microstructural, and textural characterization of the carbons. During the synthesis, impurities are removed, C-S links are formed and micropores pores are created. Sulfuric acid acts like S-dopant. The latent pores, or pores closed to nitrogen, can be found using CO2 adsorption, and are very suitable for accommodation for sodium. The results reveal that the reversible capacity is raised from ca. 200 mAh g-1 to ca. 250 mAh g-1 for the carbon obtained through treatment with sulfuric acid. The improved electrochemistry is the result of the s-doping and the porosity.

Electrophoretically deposited nickel titanate/CNT composite as promising anode for lithium/sodium ion batteries

In this study, we have demonstrated that electrophoretically fabricated NiTiO3 (NTO)/CNT composite is a viable negative electrode for lithium and sodium ion batteries, with favorable electrochemical performance. NTO/CNT exhibited initial discharge capacity of 1032 mAhg−1 and 751 mAhg−1 at 100 mAg−1 with a retained capacity of ∼ 412 mAhg−1 and ∼ 180 mAhg−1 even after 100 cycles against lithium and sodium ion respectively. CNT helps in buffering the volume fluctuations by giving structural stability and enables good cycle life performance. Also such good performance can be ascribed to the porous microstructure, good adherence property with the current collector and uniform active material distribution with carbon black and CNT on the deposited film.

Conversion Electrodes for Rechargeable Li-Sulfur, Na-Ion and Zn-Air Batteries

Rechargeable batteries are reliable and highly efficient energy storage devices providing high energy density at high voltages with the lead of the Li-ion technology since the early 1990s. Despite these promising advantages, the strongly limited abundance of Li and also that of other elements contained in a Li-ion battery (LIB) leads to the search for low-cost and more abundant alternatives. Especially for stationary storage devices alternative battery technologies are required. Alternative chemistries, such as those based on lithium conversion or alloying, can actually lead to higher energy density compared to the lithium (de)intercalation one.Among them, the lithium-sulfur (Li/S) conversion process appeared as one of the most promising candidates to achieve a lithium battery with enhanced performances compared to the state-of-art. In fact, sulfur electrode can deliver in lithium cell a theoretical capacity and energy density as high as 1675 mAh gS −1 and 2600 Wh kg−1 Unfortunately, soluble polysulfides can migrate and directly react with the lithium anode or shuttle between anode and cathode throughout a continuous process without any charge accumulation. This leads to efficiency decrease, active material loss or even to short circuits and cell failure, whilst insoluble polysulfides can precipitate into the cell and cause resistance increase and capacity fading. The characteristic electrochemical process involving at the cathode side the electro-deposition/dissolution of soluble species focused the attention on the nature of the current collector. Hence, flat and thin metal supports (e.g., bare Al current collector) may lead to poor performances due to high overall impedance of the cell and modest ability in allowing the complex multi-step reaction pathway, whilst thicker porous supports (e.g., gas diffusion layer, GDL) can enhance the cell response, reduce the impedance and actually boost the kinetics of the Li/S process, but suffer from its higher thickness, lowering down the volumetric energy density of the overall cell.In this view, graphene-based materials can actually allow the thinnest configuration of a carbon-coated metal support and hold, at the same time, a suitable Li/S process due to their characteristic morphology, mechanical stability and enhanced electronic conductivity. In regard to this, research activities are going to be presented about an exploited binder-free few layer graphene (FLG) thin carbon-coated Aluminum support for application in a Li/S cell with excellent characteristics in terms of stability, efficiency and delivered capacity.Conversion electrodes play also an important role for sodium-ion batteries (SIBs) being a promising alternative, since Na cells show similar properties to the Li analogues in many cases, while they are based on more environmentally friendly and/or more abundant materials. The use of SIBs often results slightly lower energy densities and cell voltages than those of LIBs, but they still provide significantly better values than lead-acid batteries, which are currently dominating the market in terms of annually manufactured capacity. Tin (Sn) and its compounds are well investigated alloy electrodes for SIBs as tin provides a very high theoretical specific capacity of 847 mAh g−1. Sn is an example that shows even better capacity retention when used in SIBs compared to its use in LIBs. Moreover, transition metal compounds containing phosphorus (P) and/or sulfur (S) are promising conversion electrodes as well, since these elements enable high specific volumetric and/or gravimetric capacities in LIBs and SIBs.In addition to LIBs and SIBs, zinc batteries are also attracting research interest due to their environmental friendliness and their applicability with aqueous electrolytes. However, especially zinc-air batteries are well established for use as primary cells, but when considered for use as secondary cells, they suffer from their low rechargeability. Despite great research efforts to solve these problems, no established system has yet been able to achieve reasonable rechargeability in the context of using the commonly considered alkaline electrolytes. However, Sun et al. (2021) found a promising approach using Zn(OTf)2 salt in a small amount of water as an electrolyte. This approach enables the formation of zinc peroxide (ZnO2) instead of formation the irreversible zinc oxide (ZnO) in alkaline electrolytes, which deposits on the gas diffusion layer electrode, blocking the oxygen evolution reaction. ZnO2, on the other hand, has been shown to be highly reversibly malleable. In our current project WaZABi, we are trying another approach using a freeze-cast zinc anode, which enables high porosity, and the application of a hybrid electrolyte under participance of a polymer for rechargeable high performance zinc air batteries.