Metal-ion Batteries Research Articles

Thermodynamic and Kinetic Behaviors of Electrolytes Mediated by Intermolecular Interactions Enabling High-Performance Lithium-Ion Batteries.

Electrolyte solvation chemistry regulated by lithium salts, solvents, and additives has garnered significant attention since it is the most effective strategy for designing high-performance electrolytes in lithium-ion batteries (LIBs). However, achieving a delicate balance is a persistent challenge, given that excessively strong or weak Li+-solvent coordination markedly undermines electrolyte properties, including thermodynamic redox stability and Li+-desolvation kinetics, limiting the practical applications. Herein, we elucidate the crucial influence of solvent-solvent interactions in modulating the Li+-solvation structure to enhance electrolyte thermodynamic and kinetic properties. As a paradigm, by combining strongly coordinated propylene carbonate (PC) with weakly coordinated cyclopentylmethyl ether (CPME), we identified intermolecular interactions between PC and CPME using 1H-1H correlation spectroscopy. Experimental and computational findings underscore the crucial role of solvent-solvent interactions in regulating Li+-solvent/anion interactions, which can enhance both the thermodynamic (i.e., antireduction capability) and kinetic (i.e., Li+-desolvation process) aspects of electrolytes. Additionally, we introduced an interfacial model to reveal the intricate relationship between solvent-solvent interactions, electrolyte properties, and electrode interfacial behaviors at a molecular scale. This study provides valuable insights into the critical impact of solvent-solvent interactions on electrolyte properties, which are pivotal for guiding future efforts in functionalized electrolyte engineering for metal-ion batteries.

Diffusion and structure of propylene carbonate-metal salt electrolyte solutions for post-lithium-ion batteries: From experiment to simulation.

The diffusion of cations in organic solvent solutions is important for the performance of metal-ion batteries. In this article, pulsed field gradient nuclear magnetic resonance experiments and fully atomistic molecular dynamic simulations were employed to study the temperature-dependent diffusive behavior of various liquid electrolytes representing 1M propylene carbonate solutions of metal salts with bis(trifluoromethylsulfonyl)imide (TFSI-) or hexafluorophosphate (PF6-) anions commonly used in lithium-ion batteries and beyond. The experimental studies revealed the temperature dependence of the diffusion coefficients for the propylene carbonate (PC) solvent and for the anions following an Arrhenius type of behavior. It was observed that the PC molecules are the faster species. For the monovalent cations (Li+, Na+, K+), the PC solvent diffusion was enhanced as the cation size increased, while for the divalent cations (Mg2+, Ca2+, Sr2+, Ba2+), the opposite trend was observed, i.e., the diffusion coefficients decreased as the cation size increased. The anion diffusion in LiTFSI and NaTFSI solutions was found to be similar, while in electrolytes with divalent cations, a decrease in anion diffusion with increasing cation size was observed. It was shown that non-polarizable charge-scaled force fields could correspond perfectly to the experimental values of the anion and PC solvent diffusion coefficients in salt solutions of both monovalent (Li+, Na+, K+) and divalent (Mg2+, Ca2+, Sr2+, Ba2+) cations at a range of operational temperatures. Finally, after calculating the radial distribution functions between cations, anions, and solvent molecules, the increase in the PC diffusion coefficient established with the increase in cation size for monovalent cations was clearly explained by the large hydration shell of small Li+ cations, due to their strong interaction with the PC solvent. In solutions with larger monovalent cations, such as Na+, and with a smaller solvation shell of PC, the PC diffusion is faster due to more liberated solvent molecules. In the salt solutions with divalent cations, both the anion and the PC diffusion coefficients decreased as the cation size increased due to an enhanced cation-anion coordination, which was accompanied by an increase in the amount of PC in the cation solvation shell due to the presence of anions.

Electrochemical Na+/K+ Ion Exchange in Zeolitic Vanadium(IV) Borophosphate K1.33Na0.67[VO(B2O)(PO4)2(HPO4)]·1.63H2O as Cathode Material for Sodium-Ion Batteries.

Electrochemical ion exchange has recently been demonstrated to be a unique method for the preparation of novel cathode materials, which cannot be accessible by traditional direct synthesis routes. In this study, the vanadium borophosphate compound K1.33Na0.67[VO(B2O)(PO4)2(HPO4)]·1.63H2O (KNVBP) with zeolitic framework exhibits fast electrochemical Na+/K+ ion exchange when used as cathode material in sodium-ion batteries (SIBs). Ex situ structural analyses and electrochemical measurements confirm that most of the K+ ions in the parent KNVBP can be extracted and exchanged by Na+ ions after the first charge/discharge cycle. The in situ-generated Na-rich phase shows reversible electrochemical activity at approximately 3.9 V versus Na+/Na with a specific capacity of 52.9 mAh g-1, comparable to 96.2% of the theoretical capacity. Moreover, enhanced ionic diffusion kinetics can be achieved after the Na+/K+ exchange. This study provides a valuable insight into the electrochemical ion exchange in polyanion compounds toward application in metal-ion batteries.

Aqueous Multivalent Metal-ion Batteries: Toward 3D-printed Architectures.

Energy storage has become increasingly crucial, necessitating alternatives to lithium-ion batteries due to critical supply constraints. Aqueous multivalent metal-ion batteries (AMVIBs) offer significant potential for large-scale energy storage, leveraging the high abundance and environmentally benign nature of elements like zinc, magnesium, calcium, and aluminum in the Earth's crust. However, the slow ion diffusion kinetics and stability issues of cathode materials pose significant technical challenges, raising concerns about the future viability of AMVIB technologies. Recent research has focused on nanoengineering cathodes to address these issues, but practical implementation is limited by low mass-loading. Therefore, developing effective engineering strategies for cathode materials is essential. This review introduces the 3D printing-enabled structural design of cathodes as a transformative strategy for advancing AMVIBs. It begins by summarizing recent developments and common challenges in cathode materials for AMVIBs and then illustrates various 3D-printed cathode structural designs aimed at overcoming the limitations of conventional cathode materials, highlighting pioneering work in this field. Finally, the review discusses the necessary technological advancements in 3D printing processes to further develop advanced 3D-printed AMVIBs. The reader will receive new fresh perspective on multivalent metal-ion batteries and the potential of additive technologies in this field.

Comparative Issues of Metal-Ion Batteries toward Sustainable Energy Storage: Lithium vs. Sodium

In recent years, batteries have revolutionized electrification projects and accelerated the energy transition. Consequently, battery systems were hugely demanded based on large-scale electrification projects, leading to significant interest in low-cost and more abundant chemistries to meet these requirements in lithium-ion batteries (LIBs). As a result, lithium iron phosphate (LFP) share has increased considerably due to lower cost and higher safety compared to conventional nickel and cobalt-based chemistries. However, their fast-growing share is affected by updated chemistries, where cheaper systems like sodium-ion batteries (SIBs) are becoming more attractive. SIBs also benefited from the greener, more ethical, and evenly distributed elemental resources. SIBs are fast approaching market thanks to mature LIB’s technology and manufacturing scalability using existing Li-ion gigafactories. Additionally, SIBs can be adapted to other emerging technologies, including Li-ion batteries and silicon-based anodes, influencing projections for their broader use. However, despite the lower cost and abundance of sodium chemistries compared to lithium ones, limited manufacturing capacity discourages material suppliers from increasing production, which restricts the supply chain, raises costs, and diminishes Na battery manufacturing. Here, we aim to provide an overview of the progress of SIBs in gaining market share from LIBs. We first reviewed LIB and SIB histories, developments, and market share. Then, we analyzed the offered chemicals in battery components, their resources and supplies, material demand, and supply chain. The commercialization of each system was investigated in addition to the challenges related to energy density, environmental impact, sustainability, and safety. If all these concerns are addressed properly, LIBs and SIBs could potentially offer a more affordable, safer, and sustainable choice for the global energy storage outlook, particularly in short-range electric vehicles and stationary grid storage.

A first-principles research on the properties of two-dimensional penta-BP2 as an anode material for both Na and K ion batteries

The escalating demand for large-scale energy storage solutions has sparked significant interest in metal-ion batteries, particularly in the realm of high-performance anode materials. This work explores the potential of penta-BP2 as an anode material for sodium and potassium-ion batteries through first-principles calculations. The two-dimensional metallic structure of penta-BP2 exhibits favorable electrical conductivity, making it an ideal candidate for anode materials. Theoretical analysis reveals that penta-BP2 can adsorb two layers of Na and three layers of K, resulting in high storage capacities of 1105 and 1473 mAh/g, along with low open-circuit voltages of 0.40 and 0.30 V, respectively. These characteristics enable the production of high energy density in sodium and potassium-ion batteries. Additionally, the material's small Young's modulus and low diffusion energy barriers further establish penta-BP2 as a flexible anode material capable of rapid charge/discharge processes.

Revealing Roles of High-Electronegativity Fluorine Atoms in Boosting Redox Potential of Layered Sodium Cathodes.

The development of high-energy-density cathode materials is regarded as the ultimate goal of alkali metal-ion batteries energy storage. However, the strategy of regulating specific capacity is limited by the theoretical capacity, and meanwhile focusing on improving capacity will lead to structural destructions. Herein, a novel perspective is proposed that tuning the electronic band structure by introducing highly electronegative fluoride atoms in NaxTMO2-yFy (0 < x < 1, 0 < y < 2) model compounds to improve redox potential for developing high-energy-density layered oxides. Highly electronegative fluoride atoms is introduced into P2-type Na0.67Fe0.5Mn0.5O2 (NFM), and the thus fluoride NFM (F-NFM) cathode achieved high redox potential (3.0V) and high energy density (446Whkg-1). Proved by structural characterizations, fluorine atoms are successfully incorporated into oxygen sites in NFM lattice. Ultraviolet photoelectron spectroscopy is applied to quantitatively analyze the improved redox potential of F-NFM, which is achieved by the decreased valence band energy in electronic band structure due to the strongly electrophilic fluoride ions. Moreover, fluoride atoms can stabilize the local environment of NFM and improve its redox potential. The work provides a perspective to improve redox potential by tuning the electronic band structure in layered oxides and developing high-energy-density alkali metal-ion batteries.

Iterative design of polymer fabric cathode for metal-ion batteries

Organic electrode materials (OEMs) have attracted significant attention for use in aqueous zinc-ion batteries (AZIBs) because of their abundant resources and flexible designability. However, the development of high-performance OEMs is strongly hindered by their high solubility, poor conductivity, sluggish ion diffusion kinetics, and difficult coordination toward Zn2+. Herein, inspired by fabric crafts, we have designed a robust polymer fabric through the iterative evolution of the building blocks from point to line and plane. The evolution from point to line could not only improve the structural stability and electrical conductivity but also adjust the active site arrangement to enable the storage of Zn2+. In addition to further boosting the aforementioned properties, the evolution from line to plane could also facilitate the construction of noninterference channels for ion migration. Accordingly, the poly(1,4,5,8-naphthalenetetracarboxylic dianhydride/2,3,5,6-tetraaminocyclohexa-2,5-diene-1,4-dione) (PNT) polymer fabric has the most enhanced structural stability, optimized active site arrangement, improved electrical conductivity, and suitable ion channels, resulting in a record-high capacity retention of 96% at a high mass loading of 56.9mg cm−2 and a stable cycle life of more than 20,000 cycles at 150C (1C=200 mA g−1) in AZIBs. In addition, PNT exhibits universality for a wide range of ions in organic electrolyte systems, such as Li/Na/K-ion batteries. Our iterative design of polymer fabric cathode has laid the foundation for the development of advanced OEMs to promote the performance of metal-ion batteries.

Integrated Supervised and Unsupervised Machine Learning Approach to Map the Electrochemical Windows Over 4500 Solvents for Battery Applications.

The compatibility between solvent electrolytes and high-voltage electrode materials represents a significant impediment to the progress of rechargeable metal-ion batteries. Rapidly identifying suitable solvent electrolytes with optimized electrochemical windows (ECWs) within an extensive search space poses a formidable challenge. In this study, we introduce a combined supervised and unsupervised (clustering) machine learning (ML) approach to discern distinct clusters of solvent electrolytes exhibiting varying ECW ranges. Through supervised machine learning, we have accurately predicted optimal solvent electrolytes with desired ECWs from a vast pool of 4882 solvents. Our ML model boasts superior accuracy compared to previously reported data from density functional theory (DFT). Besides, the exploration of the vast solvent space through K-means clustering (unsupervised approach) yields 11 optimal clusters, each encompassing different solvents characterized by diverse ECW ranges and frequencies. The expedited reduction of solvent space achieved through clustering occurs within a very short time frame and with minimal resource expenditure. Consequently, this method is highly capable of streamlining the subsequent experimental investigations for battery applications, avoiding the need for a trial-and-error approach.

Covalent triazine frameworks (CTFs) drive innovative advances in rechargeable metal-ion batteries: a review

In the field of energy storage technology, the organic electrodes, separators, and electrolytes have unique advantages over inorganic materials, such as low cost, environmental friendliness, and a wide range of applications. Due to the advantages of organics such as light elements, abundant reserves, and recyclability, they have become favorable candidate materials for solving the energy storage problems caused by the fossil energy crisis. In recent years, as a high-performance branch of covalent organic frameworks, covalent triazine structures (CTFs) have attracted great interest due to their applications in electrochemical energy storage. CTFs have gradually become excellent organic materials for metal-ion batteries applications due to their large specific surface area, nitrogen richness, customizable structural features, and electron donor-acceptor/conductive parts. However, the relatively poor conductivity of the triazine ring in the main structure and the harsh polycondensation conditions limit its commercial application. To overcome these challenges, many effective strategies have emerged in terms of structural optimization, functional construction, and triazine-based composites. This review summarizes in detail the synthesis methods and applications of CTFs cathodes, electrolytes, and separators in the past decade. It is found that for CTFs, large-scale synthesis methods and performance regulation strategies have reached a bottleneck. It is hoped that the systematic summary of this review will provide strategic screening and prospects for the further expansion of CTFs research in next-generation batteries.

MXenes and their composites for advanced cathodes in multivalent ion batteries

In recent years, multivalent metal-ion batteries (MMIBs) have garnered significant attention and research interest because of their abundant natural reserves, low cost, and high safety. However, in practical applications, owing to the high charge density of multivalent metal ions and the strong interaction between the intercalated metal ion and the cathode, the cathode exhibits low capacity and poor cycle stability. Therefore, it is crucial to explore suitable cathode materials for use in MMIBs. MXenes are novel two-dimensional materials that have developed rapidly in the field of energy storage. The current use of MXenes as cathodes in MMIBs has not yet been systematically summarized. This review summarizes the evolution and achievements of MXene-based cathodes in MMIBs, including MXenes and their derivatives, MXene/transition metal oxide composites, MXene/sulfur-based material composites, MXene/selenium-based material composites, and other MXene composites. Finally, the current challenges and future development of MXenes for advanced cathodes in MMIBs are discussed.

Potassium Metal Underpotential Deposition in Crystalline Carbon of Potassium‐Ion Batteries

AbstractCarbon materials, owing to their low cost, high conductivity, and good thermal and chemical stability, have been deemed as a promising anode candidate for potassium‐ion batteries. However, anomalous low‐voltage discharge situations in crystalline carbon materials imply uncertainty in the potassium storage mechanism. Herein, an overlooked scenario, i.e., potassium metal underpotential deposition (PMUPD), is disclosed in crystalline carbon materials for the first time. The study unveils the induction of interlayer pores on desolvation and PMUPD by insights from thermodynamics, kinetics, and experimental analyses. By manipulating the cutoff voltage to utilize partial PMUPD, a novel synergistic mechanism of co‐intercalation and PMUPD is revealed. A remarkable initial coulombic efficiency of 92% and a 65% capacity retention at 30C (80 mAh g−1) are realized in crystalline carbon anode. This work provides a new insight into the potassium storage mechanism of carbon anode and contributes to further research and application of the UPD behavior in other alkaline metal ion batteries.

Development of V2O3 Nanostructures for Alkali Metal Ion Batteries: A Novel Approach through Mild Metal Vapor Reduction and Interface Engineering.

V2O3 has been extensively researched as a battery electrode material due to its ample reserves and high theoretical capacity. However, the synthesis of valence-sensitive V2O3 presents technical challenges as it requires a strict combination of high-temperature treatment and a narrow range of oxygen partial pressures. This study proposes a gentle Li vapor-assisted thermal reduction method to synthesize pure-phase V2O3 at a relatively low temperature of 480 °C without any hazardous gases. It has been discovered that reducing the temperature also improves the specific surface area of the nanoto-mesoscale hierarchical structures and enhances the reactive sites between their secondary grains. These advantages enable the V2O3 micronano particles to store higher levels of Li+, Na+, and K+, increase ionic transport, and tolerate volume expansion. It demonstrates a significant capacity of 767 mA h g-1 in lithium-ion batteries, 393 mA h g-1 in sodium-ion batteries, and 209 mA h g-1 in potassium-ion batteries. It has also been discovered that the crystal structure of V2O3 is easily adjustable by varying the synthesis temperature, which significantly affects the electrochemical storage mechanism. The V2O3 synthesized at 480 °C with low crystallinity exhibits a notable intercalation reaction, facilitating the electrochemical kinetics of reversible insertion/extraction of Li+, Na+, and K+. In contrast, the highly crystalline sample synthesized at 580 °C displays pseudocapacitance behavior instead of an intercalation reaction. The highly crystalline sample synthesized at 680 °C exhibits a thorough pseudocapacitance reaction possessing the capacitive functionality for the electrochemical storage of Na+ or K+ with larger ion radii. This study describes a new synthesis strategy and rational modification of vanadium-based electrodes for alkali metal ion batteries, leading to the development of reasonably priced rechargeable battery systems with applications extending beyond lithium-ion batteries.

A Dual Salt/Dual Solvent Electrolyte Enables Ultrahigh Utilization of Zinc Metal Anode for Aqueous Batteries.

Rechargeable aqueous zincbatteriesare promising in next-generation sustainable energy storage. However, the low zinc (Zn) metal anode reversibility and utilization in aqueous electrolytes due to Zn corrosion and poor Zn2+ deposition kinetics significantly hinder the development of Zn-ion batteries. Here, a dual salt/dual solvent electrolyte composed of Zn(BF4)2/Zn(Ac)2 in water/TEGDME (tetraethylene glycol dimethyl ether) solvents to achieve reversible Zn anode at an ultrahigh depth of discharge (DOD) is developed. An "inner co-salt and outer co-solvent" synergistic effect in this unique dual salt/dual solvent system is revealed. Experimental results and theoretical calculations provide evidence that the ether co-solvent inhibits water activity by forming hydrogen bonding with the water and coordination effects with the proton in the outer Zn2+ solvation structure. Meanwhile, the anion of zinc acetate co-salt enters the inner Zn2+ solvation structure, thereby accelerating the desolvation kinetics. Strikingly, based on the electrolyte design, the zinc anode shows high reversibility at an ultrahigh utilization of 60% DOD with 99.80% Coulombic efficiency and 9.39 mAh cm-2 high capacity. The results far exceed the performance reported in electrolyte design work recently. The work provides fundamental insights into inner co-salt and outer co-solvent synergistic regulation in multifunctional electrolytes for reversible aqueous metal-ion batteries.

Engineering ternary hydrated eutectic electrolytes to realize rechargeable cathode-free aluminum-ion batteries

Aluminum-ion batteries (AIBs) have been highlighted as a promising candidate for large-scale energy storage due to the abundant reserve, low cost, high specific capacity, and good safety of aluminum. However, the development of AIBs is hindered by the usage of expensive, corrosive, and humidity-sensitive AlCl3-based ionic liquid electrolytes. Herein, we develop a low-cost, non-corrosive, and air-stable ternary hydrate eutectic electrolyte (HEE) composed of aluminum nitrate hydrate, manganese nitrate hydrate, and N,N-dimethylacetamide for cathode-free AIBs. The solvation structure of metal cations and water state in the electrolyte are regulated through the coordination of both water and N,N-dimethylacetamide molecules. The unique structural features of the HEE enables reversible deposition/stripping of AlxMnO2 on the cathodic current collector that are confirmed by various in-situ and ex-situ characterizations, ultimately realizing cathode-free AIBs. The architected cathode-free AIB delivers a discharge specific capacity of 361 mAh g−1 and shows good cycling stability and high air stability. This study provides a valuable insight into the design of rechargeable multi-valent metal ion batteries for advanced large-scale energy storage systems.

Dynamical Janus Interface Design for Reversible and Fast-Charging Zinc-Iodine Battery under Extreme Operating Conditions.

Aqueous zinc (Zn) iodine (I2) batteries have emerged as viable alternatives to conventional metal-ion batteries. However, undesirable Zn deposition and irreversible iodine conversion during cycling have impeded their progress. To overcome these concerns, we report a dynamical interface design by cation chemistry that improves the reversibility of Zn deposition and four-electron iodine conversion. Due to this design, we demonstrate an excellent Zn-plating/-stripping behavior in Zn||Cu asymmetric cells over 1000 cycles with an average Coulombic efficiency (CE) of 99.95%. Moreover, the Zn||I2 full cells achieve a high-rate capability (217.1 mA h g-1 at 40 A g-1; C rate of 189.5C) at room temperature and enable stable cycling with a CE of more than 99% at -50 °C at a current density of 0.05 A g-1. In situ spectroscopic investigations and simulations reveal that introducing tetraethylammonium cations as ion sieves can dynamically modulate the electrode-electrolyte interface environment, forming the unique water-deficient and chloride ion (Cl-)-rich interface. Such Janus interface accounts for the suppression of side reactions, the prevention of ICl decomposition, and the enrichment of reactants, enhancing the reversibility of Zn-stripping/-plating and four-electron iodine chemistry. This fundamental understanding of the intrinsic interplay between the electrode-electrolyte interface and cations offers a rational standpoint for tuning the reversibility of iodine conversion.

The electronic, magnetic, and optical behaviors of graphyne modulated by metal atoms adsorption: a first-principles study

The electronic, magnetic, and optical behaviors of graphyne modulated by various adsorbed metal atoms (Li, Na, K, Mg, Ca, Al, and Zn) from typical metal-ion batteries are studied by first-principles calculation. Notably, Mg and Zn adsorption systems are deemed unstable. In contrast, Li, Na, K, Ca, and Al systems exhibit two preferential adsorption sites, with the optimal position being the hollow center site within the large acetylenic ring. Upon the adsorption of these metal atoms, except for Ca adsorption systems exhibit semi-metallic behavior, while the other metal adsorption systems induced a transition from p-type to n-type semiconductors with decreased band gaps. Intriguingly, the inherent magnetism of the metal atoms vanished, resulting in a total magnetic moment of 0 μ B for the adsorption systems. Furthermore, the optical absorption and reflectivity peak positions for Ca adsorption systems show a significant redshift from violet to green and blue light regions. Conversely, other adsorption systems exhibit new absorption and reflection peaks in the infrared range, accompanied by an increase in both absorption coefficient and reflectivity across various spectral regions. These findings are conducive to the application in the field of novel optoelectronics and optical films.

Strain-induced intercalation of alkali metals (Li、Na、K) into Gr/2H(1T)-MoS2 heterostructure

The MoS2/C heterostructure, characterized by sizeable interlayer spacing and good reversible capacity, exhibits excellent potential as an anode material for alkali metal ion batteries. Using first-principles calculations, we systematically analyzed the intercalation of alkali metals (Li, Na, and K) into graphene/2H(1T)-phase molybdenum disulfide (Gr/2H(1T)-MoS2) heterostructures under strain by lattice engineering. The results show that the 1T-phase heterostructure exhibits a higher intercalation energy for alkali metals than the 2H-phase heterostructure. Strain reduces the intercalation energy of the system, facilitating the intercalation of alkali metals into host materials. An 8% strain reduces the intercalation energy of Li in the 1T-phase heterostructure by 72.8%. To rationalize the results, we assessed the charge transfer between the alkali metal and the host material and studied the d-band and p-band centers as a function of strain. The findings confirm that strain significantly enhances the electrical properties of Gr/2H(1T)-MoS2 heterostructures, offering a novel approach to designing anodes for alkali metal ion batteries.

Recent Progress and Perspectives on Metal–Organic Framework-Based Electrode Materials for Metal-Ion Batteries and Supercapacitors

Recent Progress and Perspectives on Metal–Organic Framework-Based Electrode Materials for Metal-Ion Batteries and Supercapacitors

Mini-Review on Organic Electrode Materials: Recent Breakthroughs and Advancement in Metal Ion Batteries

Mini-Review on Organic Electrode Materials: Recent Breakthroughs and Advancement in Metal Ion Batteries