Cathode Material For Batteries Research Articles

High-Entropy Configuration Strategy to Build High Performance Na-Ion Layered Oxide Cathodes Derived from Simple Techniques.

Layered transition metal oxides are commonly used as the cathode materials in sodium-ion batteries due to their low cost and easy manufacturing. However, the application is hindered by poor rate performance and complex phase transitions. To address these challenges, a new seven-component high-entropy layered oxide cathode material, O3-NaNi0.25Fe0.15Mn0.3Ti0.1Sn0.05Co0.05Li0.1O2 (HEO) has been developed. The entropy stabilization effect plays a crucial role in improving the performance of electrochemical systems and the stability of structures. The HEO exhibits a specific discharge capacity of 154.1 mA h g-1 at 0.1 C and 94.5 mA h g-1 at 7 C. In-situ and ex-situ XRD results demonstrate that the HEO effectively retards complex phase transitions. This work provides a high-entropy design for the storage materials with a high energy density. Meanwhile, it eliminates industry doubts about the performance of sodium ion layered oxide cathode materials.

Manipulating Local Chemistry and Coherent Structures for High-Rate and Long-Life Sodium-Ion Battery Cathodes.

Layered sodium transition-metal (TM) oxides generally suffer from severe capacity decay and poor rate performance during cycling, especially at a high state of charge (SoC). Herein, an insight into failure mechanisms within high-voltage layered cathodes is unveiled, while a two-in-one tactic of charge localization and coherent structures is devised to improve structural integrity and Na+ transport kinetics, elucidated by density functional theory calculations. Elevated Jahn-Teller [Mn3+O6] concentration on the particle surface during sodiation, coupled with intense interlayer repulsion and adverse oxygen instability, leads to irreversible damage to the near-surface structure, as demonstrated by X-ray absorption spectroscopy and in situ characterization techniques. It is further validated that the structural skeleton is substantially strengthened through the electronic structure modulation surrounding oxygen. Furthermore, optimized Na+ diffusion is effectively attainable via regulating intergrown structures, successfully achieved by the Zn2+ inducer. Greatly, good redox reversibility with an initial Coulombic efficiency of 92.6%, impressive rate capability (86.5 mAh g-1 with 70.4% retention at 10C), and enhanced cycling stability (71.6% retention after 300 cycles at 5C) are exhibited in the P2/O3 biphasic cathode. It is believed that a profound comprehension of layered oxides will herald fresh perspectives to develop high-voltage cathode materials for sodium-ion batteries.

Constructing a Size-Controllable Spherical P2-Type Layered Oxides Cathode That Achieves Practicable Sodium-Ion Batteries.

P2-type layered metal oxides are regarded as promising cathode materials for sodium-ion batteries due to their high voltage platform and rapid Na+ diffusion kinetics. However, limited capacity and unfavorable cycling stability resulting from inevitable phase transformation and detrimental structure collapse hinder their future application. Herein, based on P2-type Na0.67Ni0.18Mn0.67Cu0.1Zn0.05O2, we synthesized a series of secondary spherical morphology cathodes with different radii derived from controlling precursors prepared by a coprecipitation method, which can be promoted to large-scale production. Consequently, the synthesized materials possessed a high tap density of 1.52 g cm-3 and a compacted density of 3.2 g cm-3. The half cells exhibited a specific capacity of 111.8 mAh g-1 at a current density of 0.1 C as well as an 82.64% capacity retention with a high initial capacity of 85.80 mAh g-1 after 1000 cycles under a rate of 5 C. Notably, in situ X-ray diffraction revealed a reversible P2-OP4 phase transition and displayed a tiny volume change of 6.96% during the charge/discharge process, indicating an outstanding cycling stability of the modified cathode. Commendably, the cylindrical cell achieved a capacity of 4.7 Ah with almost no change during 1000 cycles at 2 C, suggesting excellent potential for future applications.

Air Corrosion of Layered Cathode Materials for Sodium-Ion Batteries: Cation Mixing and a Practical Suppression Strategy

Air Corrosion of Layered Cathode Materials for Sodium-Ion Batteries: Cation Mixing and a Practical Suppression Strategy

Organic Electrode Materials for Energy Storage and Conversion: Mechanism, Characteristics, and Applications.

ConspectusLithium ion batteries (LIBs) with inorganic intercalation compounds as electrode active materials have become an indispensable part of human life. However, the rapid increase in their annual production raises concerns about limited mineral reserves and related environmental issues. Therefore, organic electrode materials (OEMs) for rechargeable batteries have once again come into the focus of researchers because of their design flexibility, sustainability, and environmental compatibility. Compared with conventional inorganic cathode materials for Li ion batteries, OEMs possess some unique characteristics including flexible molecular structure, weak intermolecular interaction, being highly soluble in electrolytes, and moderate electrochemical potentials. These unique characteristics make OEMs suitable for applications in multivalent ion batteries, low-temperature batteries, redox flow batteries, and decoupled water electrolysis. Specifically, the flexible molecular structure and weak intermolecular interaction of OEMs make multivalent ions easily accessible to the redox sites of OEMs and facilitate the desolvation process on the redox site, thus improving the low-temperature performance, while the highly soluble nature enables OEMs as redox couples for aqueous redox flow batteries. Finally, the moderate electrochemical potential and reversible proton storage and release of OEMs make them suitable as redox mediators for water electrolysis. Over the past ten years, although various new OEMs have been developed for Li-organic batteries, Na-organic batteries, Zn-organic batteries, and other battery systems, batteries with OEMs still face many challenges, such as poor cycle stability, inferior energy density, and limited rate capability. Therefore, previous reviews of OEMs mainly focused on organic molecular design for organic batteries or strategies to improve the electrochemical performance of OEMs. A comprehensive review to explore the characteristics of OEMs and establish the correlation between these characteristics and their specific application in energy storage and conversion is still lacking.In this Account, we initially provide an overview of the sustainability and environmental friendliness of OEMs for energy storage and conversion. Subsequently, we summarize the charge storage mechanisms of the different types of OEMs. Thereafter, we explore the characteristics of OEMs in comparison with conventional inorganic intercalation compounds including their structural flexibility, high solubility in the electrolyte, and appropriate electrochemical potential in order to establish the correlations between their characteristics and potential applications. Unlike previous reviews that mainly introduce the electrochemical performance progress of different organic batteries, this Account specifically focuses on some exceptional applications of OEMs corresponding to the characteristics of organic electrode materials in energy storage and conversion, as previously published by our groups. These applications include monovalent ion batteries, multivalent ion batteries, low-temperature batteries, redox flow batteries with soluble OEMs, and decoupled water electrolysis employing organic electrodes as redox mediators. We hope that this Account will make an invaluable contribution to the development of organic electrode materials for next-generation batteries and help to unlock a world of potential energy storage applications.

Interfacial Spinel Local Interlocking Strategy Toward Structural Integrity in P3 Oxide Cathodes.

P3-layered transition oxide cathodes have garnered considerable attention owing to their high initial capacity, rapid Na+ kinetics, and less energy consumption during the synthesis process. Despite these merits, their practical application is hindered by the substantial capacity degradation resulting from unfavorable structural transformations, Mn dissolution and migration. In this study, we systematically investigated the failure mechanisms of P3 cathodes, encompassing Mn dissolution, migration, and the irreversible P3-O3' phase transition, culminating in severe structural collapse. To address these challenges, we proposed an interfacial spinel local interlocking strategy utilizing P3/spinel intergrowth oxide as a proof-of-concept material. As a result, P3/spinel intergrowth oxide cathodes demonstrated enhanced cycling performance. The effectiveness of suppressing Mn migration and maintaining local structure of interfacial spinel local interlocking strategy was validated through depth-etching X-ray photoelectron spectroscopy, X-ray absorption spectroscopy, and in situ synchrotron-based X-ray diffraction. This interfacial spinel local interlocking engineering strategy presents a promising avenue for the development of advanced cathode materials for sodium-ion batteries.

Poly(3,4-ethylenedioxythiophene) encapsulation/intercalation boosting stability and zinc ion storage properties of vanadyl phosphates

The electrochemical properties of vanadyl phosphates as cathode materials for Zn-ion batteries have been severely hindered by their inherent poor electronic conductivity, unavoidable dissolution in aqueous solutions, and sluggish reaction kinetics. In this study, poly(3,4-ethylenedioxythiophene) (PEDOT) is introduced in vanadyl phosphates (PEDOT-VOP) through the in situ polymerization as interlayer guest species and surface coating layer, along with the generation of oxygen vacancies. The intercalated PEDOT develops strong interaction with the host layer, which can maintain its structural integrity. In addition, the PEDOT coating shell can enhance electronic conductivity together with oxygen vacancies to promote efficient electron transfer and prevent dissolution of active materials to stabilize the vanadyl phosphate core. As a result, the PEDOT-VOP electrode demonstrates a high discharge capacity of 180 mA h g−1 at 0.1 A/g with good rate performance (128 mA h g−1 at 2 A/g) and enhanced cycling stability (a capacity retention of 88.6 % after 2000 cycles at 1 A/g). The reversible Zn2+ insertion/extraction mechanism is further validated by diverse ex situ tests.

Innovative green intense tetra-eutectic solvent (ITES) for recovery via occlusion co-precipitation at room temperature

Lithium iron phosphate (LiFePO4) is the widely used cathode material for safe and high-power lithium-ion batteries (LIBs) for electric vehicles (EVs). Therefore, numerous challenges to re-manufacturing, re-use, and recovery from spent LiFePO4/C are tolerated if evaluated early in the innovation process. Herein, innovative green intense tetra-eutectic solvent (ITES) has been used to recover a new Li-metal co-intercalation compound from spent LiFePO4/C cathode material, which is simple and cost-effective. The ITES leaching concerning organic solution with active hydrogen donor-acceptor salts creates a coordination environment through occlusion co-precipitate new co-intercalation compound at room temperature. Innovative green ITES-10 solution has successfully recovered a new Li-metal co-intercalation regarding the active hydrogen donor-acceptor bonding coordination environment of ITES adequate leaching solution and proposed recovery mechanism. The ICP-MS value of recovery metal (7Li) efficiency (%) of ITES-10 leaching for spent LiFePO₄/C cathode materials reaches approximately 0.452% at room temperature for recovery of new co-intercalation compound, besides the fresh LiFePO₄/C cathode materials (as reference), approximately 0.805%, respectively. Therefore, innovative ITES is considered to recover spent Li-based cathode materials in our future works concerning high leaching recovery rates below 100 °C in experimental conditions.

Synergistic effect of interlayered doping and surface modification to improve the performance of Li-rich manganese-based cathode materials

Li-rich manganese-based oxides (LRMOs) with high energy density have been intensively studied, but their practical use as cathode materials for lithium-ion batteries is still impeded by the shortcomings such as low initial coulombic efficiency, voltage decay and poor rate capability. To address these issues, element Nb is selected to bulk dope and simultaneously surface modify the hierarchical Li1.20Mn0.54Co0.13Ni0.13O2 spheres in this work. Synergistic effect of Nb doping and surface modification on the crystalline structure and electrochemical performance of the resultant LRMOs is characterized in detail. The results suggest that Nb5+ ions are doped into the interlayer sites within the crystals while the LiMn2O4 and LiNb3O8 double layers are coated on the primary nanoparticles. The galvanostatic charge-discharge measurements reveal that the optimal LRMO-Nb2 sample can deliver the capacities of 286 and 167 mAh g−1 at the rates of 0.1 C and 5 C, respectively, and retains a capacity of 191 mAh g−1 at 1 C rate after 200 cycles. Ex-situ XRD patterns prove that the layered structure is strongly pillared by the interlayer-doped Nb5+ during the delithiation/lithiation processes. Especially, some lithium vacancies formed around Nb5+ ions can accelerate the diffusion of Li+ ions, which was proved by DFT calculations and experimental results. Our research demonstrates that cooperating of the interlayered doping of Nb5+ with surface coating of LiNb3O8 layer can improve rate capability and cyclability of the resultant LRMOs significantly.

Effect of Subtle Changes in Ni2+/Ni3+ and Particle Surface Area in LiNi0.5Mn0.5-xCoxO2 (x = 0.1 - 0.3) Cathode Materials for Lithium-Ion Batteries

Abstract In Li[Ni,Mn,Co]O2 (NMC) cathode materials, small changes in transition metal ratio and particle surface area can significantly impact capacity retention. To understand the combined effect of transition metal ratio and the particle surface area, we studied LiNi0.5Mn0.5-xCoxO2 (x = 0.1-0.3) particles with two different morphologies: dense, spherical particles and high-surface area aggregates. All compositions in this series contain the same percentage of Ni but have differing amounts of Ni2+ and Ni3+. While Ni2+ tends to induce anti-site defects predominantly in the bulk, Ni3+ promotes particle surface reconstruction, both of which negatively impact capacity retention. Upon cycling to 4.4 V for 100 cycles, we observe that particles of high surface area with high Ni3+ concentration undergo the most severe capacity degradation. However, high surface area particles with high proportion of anti-site defects undergo sluggish capacity fade. Overall, with 60% of Ni2+ and 40% of Ni3+, spherical NMC 532 particles endure the detrimental effects of anti-site defects and surface reconstruction, but neither too prominently and thus emerges as the best candidate among the studied samples. This study highlights the synergy between transition metal ratio and particle surface area and how it determines the properties of the NMC cathode materials.

Commonly used commercialized cathode materials in lithium ion batteries and the corresponding enhancement with the help of nanotechnology

Commonly used commercialized cathode materials in lithium ion batteries and the corresponding enhancement with the help of nanotechnology

Improved rate and cycling capability of V2O5@MoS2 nanocomposites as an advanced cathode material for rechargeable aqueous zinc-ion batteries

Owing to the benefits of higher energy density, reliable safety, and eco-friendliness, rechargeable aqueous zinc (Zn)-ion batteries (RAZIBs) are employed in energy storage applications. Nevertheless, the enhancement of potential cathodes is hindered by low reversibility and sluggish Zn-ion diffusion kinetics, causing deficient rate capability and modest cycling performance. Vanadic anhydride (V2O5) provides a potential in RAZIBs from its layered structure and superior capacity. Herein, molybdenum disulfide (MoS2) was combined into the V2O5 to form V2O5@MoS2 nanocomposites (NCs) via a simple hydrothermal method. The V2O5@MoS2 NCs enable Zn ions to migrate effectively between layers and stabilize volume changes during the insertion/extraction process. Moreover, the presence of MoS2 as a mediator in the framework produces additional defects, which leads to an enhanced storage area for Zn ions. The optimized V2O5@MoS2–2 NCs exhibited a cycling capacity of 230.74 mA h g−1 at 0.5 A g−1, superior rate performance (73.59 mA h g−1 at 30 A g−1), and excellent long-term cycling stability (108.16 mA h g−1 at 10 A g−1 over 6000 cycles), surpassing those of V2O5@MoS2–1, V2O5@MoS2–3, V2O5, and MoS2 counterparts. Such fascinating properties reveal that the proposed composite materials as a progressive cathode for RAZIBs.

Achieving a Deeply Desodiated Stabilized Cathode Material by the High Entropy Strategy for Sodium-ion Batteries.

Manganese-based layered oxides are currently of significant interest as cathode materials for sodium-ion batteries due to their low toxicity and high specific capacity. However, the practical applications are impeded by sluggish intrinsic Na+ migration and poor structure stability as a result of Jahn-Teller distortion and complicated phase transition. In this study, a high-entropy strategy is proposed to enhance the high-voltage capacity and cycling stability. The designed P2-Na0.67Mn0.6Cu0.08Ni0.09Fe0.18Ti0.05O2 achieves a deeply desodiation and delivers charging capacity of 158.1 mA h g-1 corresponding to 0.61 Na with a high initial Coulombic efficiency of 98.2%. The charge compensation is attributed to the cationic and anionic redox reactions conjunctively. Moreover, the crystal structure is effectively stabilized, leading to a slight variation of lattice parameters. This research carries implications for the expedited development of low-cost, high-energy-density cathode materials for sodium-ion batteries.

Orthorhombic K3V3(PO4)4: A low-temperature cathode material for potassium-ion batteries

Potassium-ion battery has been considered as a promising energy storage device with low cost and high sustainability. However, its low-temperature performance is always poor due to the large size of K+ ions and poor ion transportation capability under low temperature. In this work, a carbon-coated orthorhombic K3V3(PO4)4/C cathode material for potassium-ion batteries is developed with promising low-temperature cycle performance. At −10 °C, K3V3(PO4)4/C retains a reversible capacity of 52.2 mAh/g for 1400 cycles at a current density of 100 mA g−1. The superior low-temperature performance is attributed to its open framework structure, which provides three-dimension channels for K-ion transportation. It is revealed that V3+/V4+ redox dominates the charge compensation in K3V3(PO4)4/C during charge and discharge processes. Carbon coating can not only reduce the charge transfer resistance of the electrode and prevent electrode cracking, but also helps to the formation of CF3-rich interfaces between the cathode and electrolyte, ensuring high interfacial stability of K3V3(PO4)4/C during cycling.

On the structural evolution of pristine P2-type Na0.67Ni0.33Mn0.67O2 for symmetric full cell application

P2 type Na0.67Ni0.33Mn0.67O2 (NNMO) is a widely studied layered oxide cathode material for sodium-ion batteries (SIBs) because of its high capacity (160 mAhg-1 practically achieved) and broad voltage window (2–4.5 V). The redox activity in NNMO is shown by both Ni2+ and Mn4+ ions, making it a prospective symmetric SIB electrode material. The average working potential of the symmetric full cell is less due to the limited average working voltages of both the redoxes in a half cell between 2 V and 4.5 V, resulting in poor energy density. Herein, we report the feasibility of the NNMO symmetric full cell by widening the operational voltage window of NNMO. The electrochemical performance of NNMO half cells between 0.01 V and 4 V and the structural evolution during cycling are mapped by ex-situ XRD. Na0.44MnO2-like tunnel-type structure (Pbam) with high Na+ content (>0.90) exists at potentials close to the Mn3+/4+ redox reaction during cycling. The phase change was relatively reversible, implying that the NNMO anode works at such low voltages without the hazard of severe capacity losses. The symmetric full cell made using NNMO cycled between 0.01 V and 3 V and, at C/10 rate, delivered a capacity of ∼68 mAhg−1.

Lithium-Ion Conductive Coatings for Nickel-Rich Cathodes for Lithium-Ion Batteries.

Nickel (Ni)-rich cathodes are among the most promising cathode materials of lithium batteries, ascribed to their high-power density, cost-effectiveness, and eco-friendliness, having extensive applications from portable electronics to electric vehicles and national grids. They can boost the wide implementation of renewable energies and thereby contribute to carbon neutrality and achieving sustainable prosperity in the modern society. Nevertheless, these cathodes suffer from significant technical challenges, leading to poor cycling performance and safety risks. The underlying mechanisms are residual lithium compounds, uncontrolled lithium/nickel cation mixing, severe interface reactions, irreversible phase transition, anisotropic internal stress, and microcracking. Notably, they have become more serious with increasing Ni content and have been impeding the widespread commercial applications of Ni-rich cathodes. Various strategies have been developed to tackle these issues, such as elemental doping, adding electrolyte additives, and surface coating. Surface coating has been a facile and effective route and has been investigated widely among them. Of numerous surface coating materials, have recently emerged as highly attractive options due to their high lithium-ion conductivity. In this review, a thorough and comprehensive review of lithium-ion conductive coatings (LCCs) are made, aimed at probing their underlying mechanisms for improved cell performance and stimulating new research efforts.

Recent Advances in Catalyst Design and Performance Optimization of Nanostructured Cathode Materials in Zinc-Air Batteries.

This review focuses on the advanced design and optimization of nanostructured zinc-air batteries (ZABs), with the aim of boosting their energy storage and conversion capabilities. The findings show that ZABs favor porous nanostructures owing to their large surface area, and this enhances the battery capacity, catalytic activity, and life cycle. In addition, the nanomaterials improve the electrical conductivity, ion transport, and overall battery stability, which crucially reduces dendrite growth on the zinc anodes and improves cycle life and energy efficiency. To obtain a superior performance, the importance of controlling the operational conditions and using custom nanostructural designs, optimal electrode materials, and carefully adjusted electrolytes is highlighted. In conclusion, porous nanostructures and nanoscale materials significantly boost the energy density, longevity, and efficiency of Zn-air batteries. It is suggested that future research should focus on the fundamental design principles of these materials to further enhance the battery performance and drive sustainable energy solutions.

Unveiling the potential of Na2FePO4F@PEG composite as cathode material for sodium-ion batteries

The economic and environmental advantages of Na2FePO4F fluorophosphate have positioned it as a highly promising cathode material for sodium-ion batteries (SIBs). This recognition stems from its demonstrated potential to address key challenges in energy storage systems, making it a subject of extensive research and studies.In this paper, the preparation of Na2FePO4F powder through a simplified, upscaling, and cost-effective approach that involves the direct use of phosphoric acid is described, aiming to evaluate its electrochemical performance. The obtained orthorhombic structure (S.G. Pbcn) is mixed with varying percentages of polyethylene glycol as a carbon source (15% and 20%) to generate large specific surfaces, improve electronic conductivity, and achieve an optimized carbon content for these materials. The 15% and 20% PEG-coated Na2FePO4F are evaluated at a 2 - 4 V voltage range at C/15 in Na-half cells using two electrolyte formulations: 5% FEC 1 M NaClO4:PC and 1 M NaPF6:PC. The NaPF6/FEC electrolyte exhibits better electrochemical characteristics and high cycling stability, especially in the case of the 15% PEG-coated material. These findings are also supported by the data from differential plots and rate capabilities, highlighting the potential of the coated material for applications in high-performance energy storage applications.

Synthesis and Characterization of Na2/3[Fe1/2Mn1/2]O2 Cathode Material for Sodium Ion Batteries

<p><strong>Abstract. </strong>Recently,<strong> </strong>Na<sub>2/3</sub>[Fe<sub>1/2</sub>Mn<sub>1/2</sub>]O<sub>2</sub> has received attention as a potential candidate material for cathode sodium-ion batteries. However, this material was synthesized by a solid-state process, resulting in larger particle size and nonuniform morphology. The larger particle size will sluggish the Na ion diffusion. Here we report the synthesis of Na<sub>2/3</sub>[Fe<sub>1/2</sub>Mn<sub>1/2</sub>]O<sub>2</sub> using a simple sol-gel process. The X-ray diffraction revealed that the sample was identified as Na<sub>2/3</sub>[Fe<sub>1/2</sub>Mn<sub>1/2</sub>]O<sub>2</sub> with a hexagonal crystal structure. However, the impurities are formed at diffraction angles of 36.28°, 45.03°, and 51.23°. Calcination temperature affects the formation of the crystal phase, grain growth, morphology, and particle size. Our findings provide valuable insight into the development of Na<sub>2/3</sub>[Fe<sub>1/2</sub>Mn<sub>1/2</sub>]O<sub>2</sub>  material with desirable properties.</p><p> </p><p><strong>Keywords:</strong></p><p>Sol-Gel, Solid State, Grain Growth, Calcination, Na<sub>2/3</sub>[Fe<sub>1/2</sub>Mn<sub>1/2</sub>]O<sub>2</sub></p><p> </p>

Synergistic improvement the Zn storage performance of ZnMn2O4 quantum dots by Ni doping and in-situ electrochemical induction

Manganese-based materials have been widely recognized as the most promising cathode materials for aqueous zinc-ion batteries (ZIBs). However, due to the problems of disproportionation reaction and slow electron transport, the development of manganese-based materials is greatly limited. In this work, a carbon-coated Ni-doped ZnMn2O4 quantum dot (NZMO QD@C) were obtained by a combined strategy of gradient calcination and electrochemical induction process with Mn-MIL-100 as the precursor. The presence of 0D quantum dot structure allows ZnMn2O4 to have shorter Zn2+ diffusion pathways and more active sites. Meanwhile, the doping of Ni can promote electron rearrangement, improve conductivity, and ultimately improve the reaction kinetics and electrochemical performance of cathode materials. Furthermore, Ni doping can effectively enhance the stability of the Mn-O bond in NZMO QD@C by optimizing the Mn ion state and electronic bandgap. Therefore, the synthesized NZMO QD@C provide a higher specific capacity of 392 mAh g-1 (0.1 A g-1) and better (≈80.28 % capacity retention for more than 820 cycles at 1 A g-1) than original MO QD@C cathode. This work brings new ideas to promote the development and design of manganese-based oxide cathode materials for ZIBs.