Sodium-ion Batteries Research Articles

From Lab to Application: Challenges and Opportunities in Achieving Fast Charging with Polyanionic Cathodes for Sodium-Ion Batteries.

Sodium-ion batteries (SIBs), recognized for balanced energy density and cost-effectiveness, are positioned as a promising complement to lithium-ion batteries (LIBs) and a substitute for lead-acid batteries, particularly in low-speed electric vehicles and large-scale energy storage. Despite their extensive potential, concerns about range anxiety due to lower energy density underscore the importance of fast-charging technologies, which drives the exploration of high-rate electrode materials. Polyanionic cathode materials are emerging as promising candidates in this regard. However, their intrinsic limitation in electronic conductivity poses challenges for synchronized electron and ion transport, hindering their suitability for fast-charging applications. This review provides a comprehensive analysis of sodium ion migration during charging/discharging, highlighting it as a critical rate-limiting step for fast charging. By delving into intrinsic dynamics, key factors that constrain fast-charging characteristics are identified and summarized. Innovative modification routes are then introduced, with a focus on shortening migration paths and increasing diffusion coefficients, providing detailed insights into feasible strategies. Moreover, the discussion extends beyond half cells to full cells, addressing challenges and opportunities in transitioning polyanionic materials from the laboratory to practical applications. This review aims to offer valuable insights into the development of high-rate polyanionic cathodes, acknowledging their pivotal role in advancing fast-charging SIBs.

Understanding and Mitigating Lattice Collapse Degradation in Layered Oxide Materials for Sodium-Ion Battery Anode.

Na2Ti3O7 has attracted significant attention due to its ecofriendliness and cost-effectiveness for sodium-ion batteries. However, their limited cycling stability hampers their practical applications. Herein, we elucidate a mechanism of structural degradation caused by the heterogeneous phase transition in the Na2Ti3O7 anode using aberration-corrected (scanning) transmission electron microscopy (S)TEM and in situ TEM. It is found that the unevenly distributed phase transition results in the accumulation of strain, which promotes the growth of microcracks and eventually leads to structural decomposition and electrochemical failure. Motivated by this degradation mechanism, nanowires were proposed, and the structural stability is thus improved with the lattice strain effectively released. These findings deepen our understanding of ion transport and degradation mechanisms in intercalated layered electrode materials while emphasizing the significance of the material structure engineered for improving electrode performance.

Fast-Charging Anode Materials for Sodium-Ion Batteries.

Sodium-ion batteries (SIBs) have undergone rapid development as a complementary technology to lithium-ion batteries due to abundant sodium resources. However, the extended charging time and low energy density pose a significant challenge to the widespread use of SIBs in electric vehicles. To overcome this hurdle, there is considerable focus on developing fast-charging anode materials with rapid Na⁺ diffusion and superior reaction kinetics. Here, the key factors that limit the fast charging of anode materials are examined, which provides a comprehensive overview of the major advances and fast-charging characteristics across various anode materials. Specifically, it systematically dissects considerations to enhance the rate performance of anode materials, encompassing aspects such as porous engineering, electrolyte desolvation strategies, electrode/electrolyte interphase, electronic conductivity/ion diffusivity, and pseudocapacitive ion storage. Finally, the direction and prospects for developing fast-charging anode materials of SIBs are also proposed, aiming to provide a valuable reference for the further advancement of high-power SIBs.

Status and prospects of O3-type layered oxide cathodes for Na-ion batteries: stability, reversibility, and reaction mechanism

Status and prospects of O3-type layered oxide cathodes for Na-ion batteries: stability, reversibility, and reaction mechanism

Hierarchically Porous Vanadium-Based Cathode Materials for High-Performance Na-Ion Batteries

Sodium-ion batteries (SIBs) have emerged as a promising alternative to lithium-ion batteries (LIBs) in sectors requiring extensive energy storage. The abundant availability of sodium at a low cost addresses concerns associated with lithium, such as environmental contamination and limited availability. However, SIBs exhibit lower energy density and cyclic stability compared to LIBs. One of the key challenges in improving the performance of SIBs lies in the electrochemical properties of the cathode materials. Among the various cathodes utilized in SIBs, sodium vanadium phosphates (NVPs) and sodium vanadium fluorophosphates (NVPFs) are particularly advantageous. These vanadium-based cathodes offer high theoretical capacity and are cost-effective. Commercialization of SIBs with NVPF cathodes has already begun. However, the poor conductivity of these cathode materials leads to a short cycle life and inferior rate performance. Various synthesis methods have been explored to enhance the conductivity, including heteroatom doping (N, S, and Co), surface modification, the fabrication of porous nanostructures, and composite formation with conductive carbon materials. In particular, cathodes with interconnected hierarchical micro- and nano-porous morphologies have shown promise. This review focuses on the diverse synthesis methods reported for preparing hierarchically porous cathodes. With increased attention, particular emphasis has been placed on carbon composites of NVPs and NVPFs. Additionally, the synthesis of vanadium pentoxide-based cathodes is also discussed.

Nano-crystalline Fe3V3O8 material as an efficient advanced anode for energy storage applications

The sodium-ion battery (SIB) is a rapidly developing electrochemically rechargeable storage device and a direct substitute for Li-ion batteries. Therefore, identifying novel materials for sodium-ion storage applications is important. Efficient electrodes are particularly desirable for enhancing storage performance in battery applications. In this study, we fabricated a novel Fe3V3O8 (FVO) anode material for Na/Li-ion storage using hydrothermal technology for the first time. The electrochemical results indicated that the initial sodiation capacity of the FVO anode is as high as 805 mA h g−1 at 100 mA g−1, and a reversible sodiation capacity of 540 mA h g−1 is maintained over 200 cycles at 500 mA g−1, which is more than 1.8 times the commercial hard carbon of ∼300 mA h g−1. In addition, the oxidation states of the chemical compound and the corresponding sodium reaction mechanism are predicted using X-ray absorption spectroscopy (XAS), X-ray photoelectron spectroscopy (XPS), and in-situ/ex-situ X-ray diffraction (XRD) analysis. Overall, the FVO material exhibited significantly higher electrochemical performance, demonstrating promising suitability for sodium-ion storage.

Prussian blue analogue derived porous hollow nanocages comprising polydopamine-derived N-doped C coated CoSe2/FeSe2 nanoparticles composited with N-doped graphitic C as an anode for high-rate Na-ion batteries

CoFe-Prussian blue analogue (CoFe-PBA) templated N-doped graphitic carbon (NGC) and polydopamine-derived carbon (PDA-20) double-coated CoSe2/FeSe2 nanoparticles are introduced as anodes for highly efficient sodium-ion batteries (SIBs). These nanoparticles are encapsulated within porous hollow nanocages, which exhibit remarkable stability in cyclic performance. The synthesis method involved co-precipitation, followed by PDA coating at varying concentrations and a subsequent selenization process. This resulted in the creation of (Co,Fe)Se-NGC nanocages, (Co,Fe)Se-NGC@PDA-20 hollow nanocages, and (Co,Fe)Se-NGC@PDA-100 filled nanocages. This strategic preparation approach leverages the synergistic effects of dual carbon coating, resulting in highly conductive and porous nanostructures. These structures facilitate rapid charge species diffusion, efficient electrolyte infiltration, and effective management of volumetric changes. When used as anodes for SIBs, the (Co,Fe)Se-NGC@PDA-20 hollow nanocages demonstrate impressive structural robustness and high-rate performance. They exhibit remarkable structural integrity, maintaining stable cycling performance for up to 200 cycles at 0.5 and 1.0 A g−1. In terms of rate capability, the hollow nanocages exhibit a high discharge capacity of 126 mA h g−1 at 10 A g−1. This clearly highlights the structural advantages of the prepared hollow nanocages.

The Enormous Potential of Sodium/Potassium-Ion Batteries as the Mainstream Energy Storage Technology for Large-Scale Commercial Applications.

Cost-effectiveness plays a decisive role in sustainable operating of rechargeable batteries. As such, the low cost-consumption of sodium-ion batteries (SIBs) and potassium-ion batteries (PIBs) provides a promising direction for "how do SIBs/PIBs replace Li-ion batteries (LIBs) counterparts" based on their resource abundance and advanced electrochemical performance. To rationalize the SIBs/PIBs technologies as alternatives to LIBs from the unit energy cost perspective, this review gives the specific criteria for their energy density at possible electrode-price grades and various battery-longevity levels. The cost ($ kWh-1 cycle-1) advantage of SIBs/PIBs is ascertained by the cheap raw-material compensation for the cycle performance deficiency and the energy density gap with LIBs. Furthermore, the cost comparison between SIBs and PIBs, especially on cost per kWh and per cycle, is also involved. This review explicitly manifests the practicability and cost-effectiveness toward SIBs are superior to PIBs whose commercialization has so far been hindered by low energy density. Even so, the huge potential on sustainability of PIBs, to outperform SIBs, as the mainstream energy storage technology is revealed as long as PIBs achieve long cycle life or enhanced energy density, the related outlook of which is proceeded as the next development directions for commercial applications.

Biomass-Derived Hard Carbon for Sodium-Ion Batteries: Basic Research and Industrial Application.

Sodium-ion batteries (SIBs) have significant potential for applications in portable electric vehicles and intermittent renewable energy storage due to their relatively low cost. Currently, hard carbon (HC) materials are considered commercially viable anode materials for SIBs due to their advantages, including larger capacity, low cost, low operating voltage, and inimitable microstructure. Among these materials, renewable biomass-derived hard carbon anodes are commonly used in SIBs. However, the reports about biomass hard carbon from basic research to industrial applications are very rare. In this paper, we focus on the research progress of biomass-derived hard carbon materials from the following perspectives: (1) sodium storage mechanisms in hard carbon; (2) optimization strategies for hard carbon materials encompassing design, synthesis, heteroatom doping, material compounding, electrolyte modulation, and presodiation; (3) classification of different biomass-derived hard carbon materials based on precursor source, a comparison of their properties, and a discussion on the effects of different biomass sources on hard carbon material properties; (4) challenges and strategies for practical of biomass-derived hard carbon anode in SIBs; and (5) an overview of the current industrialization of biomass-derived hard carbon anodes. Finally, we present the challenges, strategies, and prospects for the future development of biomass-derived hard carbon materials.

Industrial‐Scale Hard Carbon Designed to Regulate Electrochemical Polarization for Fast Sodium Storage

AbstractGiven the merits of abundant resource, low cost and high electrochemical activity, hard carbons have been regarded as one of the most commercializable anode material for sodium‐ion batteries (SIBs). However, poor rate capability is one of the main obstacles that severely hinder its further development. In addition, the relationships between preparation method, material structure and electrochemical performance have not been clearly elaborated. Herein, a simple but effective strategy is proposed to accurately construct the multiple structural features in hard carbon via adjusting the components of precursors. Through detailed physical characterization of the hard carbons derived from different regulation steps, and further combined with in‐situ Raman and galvanostatic intermittent titration technique (GITT) analysis, the network of multiple relationships between preparation method, microstructure, sodium storage behavior and electrochemical performance have been successfully established. Simultaneously, exceptional rate capability about 108.8 mAh g−1 at 8 A g−1 have been achieved from RHC sample with high reversible capacity and desirable initial Coulombic efficiency (ICE). Additionally, the practical applications can be extended to cylindrical battery with excellent cycle behaviors. Such facile approach can provide guidance for large‐scale production of high‐performance hard carbons and provides the possibility of building practical SIBs with high energy density and durability.

Sodium iron sulfate cathodes with ultra-long cycle-life and high safety for sodium-ion batteries

The development of low-cost and high-safety cathode materials is critically important to sodium-ion battery (Na-ion) research. Here we report a carbon nanotube (CNT)-percolating Na2Fe(SO4)2 cathode (NFS-CNT) prepared via a rationally designed mechano-chemical method. The material synthesis mechanism is elucidated for the first time by in situ X-ray diffraction and thermogravimetric analysis. It is discovered that Na2Fe(SO4)·4H2O is formed as an intermediate phase during the mechano-chemical process, which is dehydrated to produce the Na2Fe(SO4)2 cathode material upon a mild thermal treatment. The NFS-CNT composite cathode achieves an ultra-long cycle-life of over 13,000 cycles at 10 C at room temperature and over 6000 cycles at 55 °C, demonstrating its exceptional durability. The superior cycling performance is attributed to the small lattice change during Na-ion extraction/insertion and the percolating CNT network. Furthermore, the NFS/CNT cathode exhibits stable cycle performance in Na-ion full cells (93.4 % retention after 700 cycles) and a significantly lower heat release (∼ 229.2 J g−1) at the fully charged state compared to a wide range of Na-ion and Li-ion cathodes. materials. demonstrating its high thermal stability and safety. This work provides a promising path towards developing low-cost, high-performance Na-ion batteries.

Zero-strain Co-doped Na2FeP2O7/carbon delivers superior rate capability and long-cycle stability for sodium ion batteries

Na2FeP2O7 cathode material exhibits great promise in sodium ion batteries (SIBs), due to its low cost and high structural durability. Nevertheless, the intrinsically poor electronic conductivity and sluggish Na+ diffusion kinetics of Na2FeP2O7 hinder its practical application. Herein, a synergistic cooperation of continuous amorphous carbon layer and optimized Co doping strategy is proposed to design high-performance SIB cathode (Co-doped Na2FeP2O7/C) via in-situ sol–gel method, where Co integration significantly enhances both the electronic conductivity and the Na+ diffusion kinetics, as confirmed by the combination of ex/in-situ characterizations and density functional theory calculations. Valuably, the synergy of amorphous carbon layer and appropriate Co doping restrains the structure stress to “zero-strain”, Which remains beneficial for 0.10Co-NFO@C to display a high capacity of 96.12 mAh g-1 at 0.05C and a high-rate capacity of 61.75 mAh g-1 at 60C with the capacity retention of 79.9% after 5000 cycles. Moreover, optimized Co-doped Na2FeP2O7/C also shows outstanding cycling performance and rate capability when assembled into full batteries (hard carbon as the anode), demonstrating a reversible capacity of ∼110.9 mAh g-1 at 50 mA g−1, and a respectable capacity retention of 78.0% at 500 mA g−1 for 500 cycles. The strategy inspires new advances towards zero-strained cathode materials for high performance SIBs.

Dual‐Carbon‐Coated Na2FeP2O7 Cathode Materials for Na‐Ion Batteries with Superior High‐Rate and Cycling Stability

The iron‐based pyrophosphate Na2FeP2O7 (NFP) is considered as one of the most promising cathodes for sodium‐ion batteries (SIBs) due to its low‐cost and superior structure stability, yet it usually suffers from poor intrinsic electronic conductivity. Herein, a two‐step carbon‐coating technique has been developed to synthesize high‐performance NFP@C cathode materials by controlling the NFP particle size and the coating layer uniformity. The first step of in‐situ carbon coating greatly restrains the excessive growth of NFP crystals with a shortened Na‐ion diffusion path. Meantime, the extra secondary carbon‐coating is adopted to repair some exposed areas, guaranteeing the full coverage of NFP particles for rapid electronic transfer. As a consequence, the as‐obtained NFP@C cathode delivers a high discharge capacity of 95.2 mAh g−1 at 0.1 C (theoretical value: 97 mAh g−1) and with high‐rate capability (75.2 mAh g−1 at 5 C) within 2.0–4.0 V. A capacity retention of 95.3% can be achieved even after 500 cycles at 5 C in coin‐type cells. Such superior electrochemical performances are expected to quickly promote the applications of NFP in SIBs.

Double-layer carbon coated on the micrometer bismuth by photothermal effect as anode for high-rate sodium-ion batteries

Bismuth (Bi) is considered a promising anode material for high-rate sodium-ion batteries (SIBs) due to its unique layered crystal structure which can easily insert/extract sodium-ion (Na+). However, the cycle stability of micrometer Bi with great commercial potential needs to be improved. Because the large volume change occurs during alloying/dealloying of Bi and sodium (Na) resulting in the crack of Bi, which reduces the stability of the battery. Herein, we design a Bi/Bi2O3@C composite where a double-layer carbon coated commercial micrometer Bi/Bi2O3 particles. The heat generated by Bi/Bi2O3 particles under ultraviolet (UV) exposure (called photothermal effect) accelerates the decomposition rate of photoinitiator, which in turn improves the polymerization rate of the monomer on the surface of Bi/Bi2O3 particles. So that, the surface of Bi/Bi2O3 particles is coated with a dense polymer, while the polymer away from the particle is relatively loose, thus forming a dense-loose double-layer carbon during the annealing process. The dense carbon layer can effectively protect against the volume effect of Bi/Bi2O3, and the loose carbon layer can provide channels for the transport of Na+. As a result, Bi/Bi2O3@C exhibits excellent cycling stability with a capacity retention rate of 94.5 % after 1600 cycles at 10 A g−1.

A Unique Wide-Spacing Fence-Type Superstructure for Robust High-Voltage O3-Type Sodium Layered Cathode.

Enhancing the energy density of layered oxide cathode materials is of great significance for realizing high-performance sodium-ion batteries and promoting their commercial application. Lattice oxygen redox at high voltage usually enables a high capacity and energy density. But the structural degradation, severe voltage decay, and the resultant poor cycling performance caused by irreversible oxygen release seriously restrict the practical application. Herein we introduce a novel fence-type superstructure (2a × 3a type supercell) into O3-type layered cathode material Na0.9Li0.1Ni0.3Mn0.3Ti0.3O2 and achieve a stable cycling performance at a high voltage of 4.4 V. The fence-type superstructure effectively inhibits the formation of the vacancy clusters resulting from out-of-plane Li migration and in-plane transition metal migration at high voltage due to the wide d-spacing, thereby significantly reducing the irreversible release of lattice oxygen and greatly stabilizing the crystal structure. The cathode exhibits a high energy density of 545 Wh kg-1, a high rate capability (112.8 mAh g-1 at 5C) and a high cycling stability (85.8%@200 cycles with a high initial capacity of 148.6 mAh g-1 at 1C) accompanied by negligible voltage attenuation (98.5%@200 cycles). This strategy provides a distinct spacing effect of superstructure to design stable high-voltage layered cathode materials for Na-ion batteries.

Setup Design and Data Evaluation for DEMS in Sodium Ion Batteries, Demonstrated on a Mn‐Rich Cathode Material

AbstractDifferential electrochemical mass spectrometry (DEMS) is a powerful operando method for analyzing side reactions in batteries. We describe our DEMS setup highlighting the relevance for implementing a reference electrode. Although the method provides valuable information, the correct assignment of the DEMS signals to types of gases and quantifying the amounts released can be challenging. A frequent limitation is that gas concentrations are calculated from single m/z ratios. This has the drawback of overlooking unexpected gases which can cause misinterpretation of the signal intensities, or even attributing to gases which are not actually formed. We present a multiple concentration determination (MCD) algorithm that uses the full MS‐spectra, which allows a more reliable determination of the gas release. We demonstrate this approach for Na‐ion half‐cells with P2‐Na0.67Mn3/4Ni1/4O2 (NaMNO) as cathode active material (CAM). Studying the gassing behavior for two electrolyte formulations (1 M NaPF6 in propylene carbonate (PC) and in diglyme (2G)). Against the general belief that glymes lead to more gassing at high potentials, we find that gas evolution for PC electrolytes is larger compared to 2G electrolytes. Dimethyl ether is found to be a decomposition product of 2G. Pressure change measurements are used to independently validate the gas quantification.

3D Bismuth@N-Doped carbon microflowers for ultrahigh rate and stable sodium storage

Sodium-ion batteries (SIBs) are gaining attention in the energy storage market due to their high theoretical capacity and affordability. However, challenges such as volume expansion and sluggish dynamics during sodiation/desodiation hinder their practical application. A 3D bismuth@N-doped carbon microflowers (Bi@NC) anode was successfully prepared to address these issues. The Bi nanosheets expedite Na ions and electrons transport and inhibit particle pulverization, while the N-doped carbon layer maintains electrode stability and improves electronic conductivity. The Bi@NC anode exhibits ultrahigh rate (336.7 mAh/g at 20 A/g) and stable performance (92.9% capacity retention after 2500 cycles at 5 A/g).

First principle evaluations on perovskite-type sodium trifluorides, NaMF3 (M= V, Mn, Fe, Co, Ni, and Cu), as electrode materials for Na-ion batteries

This ab initio study investigates the structural, Na diffusion channels, electrochemical, and electrical properties of NaMF3 (M= V, Mn, Fe, Co, Ni, and Cu) for as novel electrode materials for Na-ion batteries, using density functional theory (DFT) calculations. The stability and structural changes are evaluated during (de)sodiation. Considering electrochemical potential of the materials by Fermi and internal energy approaches, NaNiF3 and NaVF3 have the highest and lowest voltages, respectively. The electrical properties of the materials are examined in terms of intrinsic- and extrinsic-like band gaps. For comprehensiveness, the electrical rate-capability is estimated using two different approaches, i.e. Delta and CCTB. Consequently, utilizing various DFT approaches and evaluating properties, each considered material has its own advantages and drawbacks to be used as Na-ion electrode. Using a general perspective, this paper ranks the materials as NaCuF3, NaCoF3, NaVF3, NaMnF3, NaFeF3, and NaNiF3, respectively. This study opens a new landscape for future investigations about these promising intercalation electrode materials and also the other analogous systems.

Inhibiting the Jahn-Teller Effect of Manganese Hexacyanoferrate via Ni and Cu Codoping for Advanced Sodium-Ion Batteries.

Manganese (Mn)-based Prussian blue analogs (PBAs) are of great interest as a prospective cathode material for sodium-ion batteries (SIBs) due to their high redox potential, easy synthesis, and low cost. However, the Jahn-Teller effect and low electrical conductivity of Mn-based PBA cause poor structure stability and unsatisfactory performance during the cycling. Herein, a novel nickel- and copper-codoped K2Mn[Fe(CN)6] cathode is developed via a simple coprecipitation strategy. The doping elements improve the electrical conductivity of Mn-based PBA by reducing the bandgap, as well as suppress the Jahn-Teller effect by stabilizing the framework, as verified by the density functional theory calculations. Simultaneously, the substitution of sodium with potassium in the lattice is beneficial for filling vacancies in the PBA framework, leading to higher average operating voltages and superior structural stability. As a result, the as-prepared Mn-based cathode exhibits excellent reversible capacity (116.0 mAh g-1 at 0.01 A g-1) and superior cycling stability (81.8% capacity retention over 500 cycles at 0.1 A g-1). This work provides a profitable doping strategy to inhibit the Jahn-Teller structural deformation for designing stable cathode material of SIBs.

Pristine Metal‐Organic Frameworks for Sodium‐Ion Batteries: Past, Present, and Future

AbstractOwing to their adjustable redox‐active sites, designable structures high porosity, and fully activated organic ligands, pristine metal‐organic frameworks (MOFs) have been widely utilized as advanced electrode materials (i. e., both anodes and cathodes) for sodium‐ion batteries (SIBs) to satisfied the insertion/extraction larger size and mass of Na+ cations, achieving significant progresses with excellent electrochemical performance in electrochemical energy storage devices. Here, the recent advances on pristine MOFs as anodes and cathodes for SIBs are summarized. A thorough investigation delves into the detailed characteristics, energy storage mechanisms, and electrochemical performance of diverse pristine MOFs for SIBs are also clarified. Furthermore, the outlooks on pristine MOF electrodes in SIBs are also provided.