Materials For Sodium-ion Batteries Research Articles

Synthesis and properties optimization of Na3(VOPO4)2F cathode material for sodium-ion batteries by co-precipitation method

Na3(VOPO4)2F (NVOPF) has become one of the most promising cathodes of the large-scale application of sodium-ion batteries (SIBs) owning to its high working voltage and high discharging specific capacities properties. However, the immature synthetic routes, the tedious preparation process as well as high preparation cost restrict its promotion and application to some extent. In this work, the pure NVPOF was successfully prepared by liquid phase coordination chemistry combined with co-precipitation method based on theoretical speculation. The sodium storage performances are optimized by adjusting the key process parameters such as the pH value of solutions, the catalogue of pH regulators and the solution concentrations. When pH value of the solution is 4.50, oxovanadium sulfate solution concentration lies at c[v] = 1.5 mol L−1, the as-prepared NVPOF outperforms the optimal performances. The NVPOF cathode material synthesized under the optimized conditions boasts a perfect NASICON sodium-storage structure, spherical or quasi spherical morphology. In detail, the specific capacity is 110 mAh g−1 at 0.1 C and the discharging voltage is 3.86 V. The first coulombic efficiency is 91.4 %, and the specific capacity decay from 97 mAh g−1 to 87 mAh g−1 with 91.3 % capacity retention after 300 cycles in the half-cell system. This large-scale co-precipitation synthesis of NVOPF will provide new guidance for the development and application of cathode materials for SIBs.

Unlocking the high-capacity operation of P2-type cathode through bifunctional spectator ions substitution

The high specific capacity of the P2-type cathode endowed by the synergistic cation and anion redox makes it one of the most promising cathode materials for sodium-ion batteries (NIBs). However, the structural rearrangement and the irreversible oxygen release under highly desodiated states engender stability issues upon high-capacity operation. Herein, we show specifically how the structural degradation of the P2-type cathode is effectively stabilized by the substitution of bifunctional spectator ions. The rational incorporation of Ti and Si ions triggers the “pillar effect” and “inductive effect”, which eliminates the P2-O2/P2-P2′ structural evolution and mitigates the irreversible oxygen oxidation. Benefited from the highly reversible anion redox, the obtained Na0·67Li0·21Mn0·59Si0·01Ti0·19O2 represents a high reversible capacity of 220 mAh g−1 at 0.1C (20 mA g−1) within a Na-metal half-cell. Ex-situ XRD reveals a solid solution reaction without the formation of additional phases among the charge/discharge process, thus favoring stable cycling performance for up to 200 cycles at 2.5C (with a capacity retention rate of 88 %). This work shows, not only the specific strategies for improving the electrochemical performance of cathode materials, but also offers insights into the intrinsic mechanisms underlying the performance enhancement achieved through spectator ion substitution.

Rational design of practical layered transition metal oxide cathode materials for sodium-ion batteries

Rational design of practical layered transition metal oxide cathode materials for sodium-ion batteries

Architecting O3/P2 layered oxides by gradient Mn doping for sodium-ion batteries

O3 phase layered oxides are highly attractive cathode materials for sodium-ion batteries because of their high capacity and decent initial Coulombic efficiency. However, their rate capability and long cycling life are unsatisfactory due to the narrow Na+ transfer channel and irreversible phase transitions of O3 phase during sodiation/desodiation process. Constructing O3/P2 multiphase structures has been proven to be an effective strategy to overcome these challenges. In this study, we synthesized bi-phasic structured O3/P2 Na(Ni2/9Fe1/3Cu1/9Mn1/3)1-xMnxO2 (x = 0.01, 0.02, 0.03, 0.04, 0.05) materials through Mn doping during sodiation process. Benefiting from surface P2 phase layer with the enhanced Na+ transfer dynamics and high structural stability, the Na(Ni2/9Fe1/3Cu1/9Mn1/3)0.98Mn0.02O2 (NFCM-M2) cathode delivers a reversible capacity of 139.1 mA h g−1 at 0.1 C, and retains 71.4 % of its original capacity after 300 cycles at 1 C. Our work provides useful guidance for designing multiphase cathodes and offers new insights into the structure-performance correlation for sodium-ion cathode materials.

Optimizing interfacial modification for enhanced performance of Na3V2(PO4)3 cathode in sodium-ion batteries

A novel cathode material, Na3V2(PO4)3C@CNT (NVP/C@CNT), was designed and synthesized by a low-temperature solid-phase drying ball milling method. The nanoparticles are covered by an amorphous carbon layer, and simultaneously enveloped and embedded by carbon nanotubes on the surface. Consequently, a carbon network consisting of carbon nanotubes and amorphous carbon layers is formed in the material. Notably, no phase transition during the intercalation process of sodium ions, confirming the stable crystal structure, which ensures the stability and reversibility of the large-capacity cathode in the large-volume change. The addition of CNTs can regulate the size of NVP particles, increase the contact area between NVP and electrolyte, leading to an enhancement in the sodium ion diffusion coefficient. The NVP/C@CNT electrode exhibits a capacity of 114.5 mA h g−1 at 0.1 C. After 2650 cycles, the discharge capacity retention rate is 98.2 % at 10 C. Even at 20 C, the discharge capacity is still 93.3 mA h g−1 after 2710 cycles, with a retention rate of 99.5 %. This work provides a feasible approach for the design of low-cost, long-life, high-performance cathode materials for sodium-ion batteries.

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

Given 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.

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 mAh 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.

Surface engineering of P2-type cathode material targeting long-cycling and high-rate sodium-ion batteries

The widespread interest in layered P2-type Mn-based cathode materials for sodium-ion batteries (SIBs) stems from their cost-effectiveness and abundant resources. However, the inferior cycle stability and mediocre rate performance impede their further development in practical applications. Herein, we devised a wet chemical precipitation method to deposit an amorphous aluminum phosphate (AlPO4, denoted as AP) protective layer onto the surface of P2-type Na0.55Ni0.1Co0.1Mn0.8O2 (NCM@AP). The resulting NCM@5AP electrode, with a 5 wt% coating, exhibits extended cycle life (capacity retention of 78.4% after 200 cycles at 100 mA g−1) and superior rate performance (98 mA h g−1 at 500 mA g−1) compared to pristine NCM. Moreover, our investigation provides comprehensive insights into the phase stability and active Na+ ion kinetics in the NCM@5AP composite electrode, shedding light on the underlying mechanisms responsible for the enhanced performance observed in the coated electrode.

Chalcogen effects and cathodic properties of scandium-based materials for sodium-ion batteries

Chalcogen effects and cathodic properties of scandium-based materials for sodium-ion batteries

Constructing Ti-O-C bond in Na0.23TiO2@N-doped carbon sphere using dihydroxybenzene as an anode material for sodium-ion batteries

Na0.23TiO2 particles coated on a nitrogen-doped carbon sphere (NTO@NCS) were synthesized using dihydroxybenzene and hexamethylenetetramine as carbon and nitrogen sources, respectively. In the NTO@NCS-R sample, Na0.23TiO2 particles uniformly cover the surface of electrically conductive NCS by forming the Ti-O-C bonds between Na0·23TiO2 and NCS. The feature is favorable to provide the NTO electrode the structural robustness and sodium ion diffusion during cycling. The NTO@NCS-R electrode exhibits an outstanding discharge capacity of 193.1 mAh g−1 at 0.1 A g−1 after 300 cycles in the voltage range of 0.01–2.5 V, compared to bare Na0·23TiO2, NTO@NCS-C, and NTO@NCS-H. In addition, NTO@NCS-R exhibits a discharge capacity of 114.4 mAh g−1 at 1.0 A g−1 at 2000th cycle and 58.7 mAh g−1 at 2.0 A g−1 at 8000th cycle, respectively, proving fast sodium ion diffusion and excellent cycle stability during long-term cycles.

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.

Exploration of electrochemical behavior of Sb-based porous carbon composites anode for sodium-ion batteries

Sb-based materials are considered as promising anode materials for sodium-ion batteries (SIBs) due to their excellent sodium storage capacities and suitable potentials. However, the Sb-based anodes usually suffer from intense volume expansion and severe pulverization during the alloying-dealloying process, resulting in poor cycling performance. Herein, a composite anode with Sb/Sb2O3 nanoparticles embedded in N-doped porous carbon is prepared by the gas–solid dual template method. The volume change of the anode material is mitigated by the carbon layer enwrapping and the confinement of the porous structure. Nitrogen doping provides abundant sodium storage sites, thus enhancing the storage capacity of sodium ion. Furthermore, to gain the accurate kinetic interpretation of the electrochemical process, an ex-situ transmission electron microscope (TEM) characterization combined with distribution of relaxation times (DRT) is conducted. The Sb/Sb2O3@NPC-1.0 demonstrates excellent electrochemical performance, achieving 340.3 mAh g−1 at 1A g−1, and maintains a capacity of 86.7 % after 1000 cycles. This work paves the way for the practical application of SIBs with high-performance and long-life Sb-based anodes.

Biomass derived hard carbon materials for sodium ion battery anodes: Exploring the influence of carbon source on structure and sodium storage performance

Compared to the scarce resources of lithium-ion batteries, sodium ion batteries have gradually become an ideal carrier for large-scale energy storage systems due to their abundant raw material resources. In recent years, hard carbon as an anode material for sodium ion batteries has attracted much attention. Biomass materials have become an ideal hard carbon precursor due to their natural and renewable advantages. This article evaluates the effect of hard carbon derived from three types of biomass waste (peanut shell, coffee grounds, and sugarcane bagasse) on the electrochemical performance of sodium ion batteries through pre carbonization pyrolysis method. The three materials exhibit different structures and surface functional group contents. Compared with coffee grounds and sugarcane bagasse, peanut shell-derived hard carbon has lower structural ordering and smaller specific surface area, and exhibits a higher initial Coulombic efficiency of 53.84 %. The initial reversible capacity of the HC-P electrode is 203.6 mAh/g, and the Coulombic efficiency of the electrode is close to 100 % with a reversible capacity of 127.1 mAh/g and a capacity retention of 81.4 % after cycling 100 at 1C current. The excellent electrochemical properties of HC-P can be attributed to its higher C=O bond content, larger layer spacing and lamellar structure.

Preparation of high-performance anode materials for sodium-ion batteries using bamboo waste: Achieving resource recycling

Bamboo exhibits various excellent properties and is widely used in construction. However, appropriate disposal of the bamboo waste generated in a green manner is difficult. To realize resource recycling, we used a simple treatment method to prepare waste bamboo as a negative electrode material exhibiting considerable electrochemical properties for sodium-ion batteries. The electrochemical properties of high-temperature calcination materials considerably improved after impurity removal treatment using an acid solution, which was performed to eliminate the influence of impurities on electrochemical properties. However, the materials still could not meet commercial requirements. A simple pre-oxidation modification treatment enabled the introduction of O atoms into the carbon skeleton to expand the layer spacing, improved the transport kinetics of Na+ in the carbon skeleton, and further increased the platform capacity of the pre-oxidation material. The preoxidative high-temperature co-treated materials exhibited a specific charge capacity close to 280 mAh g−1 at a 0.1 C rate and a capacity attenuation of almost zero after 100 cycles, and showing a specific charge capacity of more than 150 mAh g−1 at a 2 C rate test. In the context of sustainable development, this study makes waste bamboo become a candidate of low-cost negative electrode material for sodium-ion batteries.

Electrochemical performance of Na4P2O7 decorated Na4MnV(PO4)3/C cathode material for sodium-ion batteries

Na4P2O7 decorated Na4MnV(PO4)3/C (NMVP-SP) composites were prepared by a simple sol–gel method combined with high-temperature calcination in inert atmosphere. As a cathode material for sodium-ion batteries, the optimal NMVP-SP presents much higher capacity, better rate capability and cyclability than Na4MnV(PO4)3/C, which is attributed to Na4P2O7 coating that has good ionic conductivity and inhibits the manganese dissolution from Na4MnV(PO4)3 in electrolyte.

Enhancing the sodium-ion storage performance of two-dimensional layered Ti3CN with a molecular riveting strategy

Adjustable 2D layered MXenes hold considerable promising as anode materials for sodium-ion batteries. However, the serious self-stacking and volume variation during sodium-ions insertion/extraction processes inevitably result in inferior rate capability and terrible cycle stability. Herein, we report a novel and effective “molecular riveting” strategy to simultaneously adjust the interlayer spacing and stabilize layered structure of Ti3CN (TCN), which is realized by riveting L-Aspartic acid/L-Glutamic acid/L-2-Aminoadipic acid (LAA/LGA/L2AA, abbreviated as LXA) molecules into interlayers of TCN (named as LAA-TCN/LGA-TCN/L2AA-TCN and abbreviated as LXA-TCN) to form strong amido (HN-C = O) bonds. The riveted LXA molecules between the interlayer of TCN contribute double effects of pillar and strain, achieving the maximum utilization of the 2D layered TCN. As consequences, the interlayer spacing of TCN can be broadened from 1.04 nm to 1.31 nm via altering the carbon chain length of LXA molecules, and the Na+ migration barrier can be reduced from 0.71 eV to 0.08 eV. Meanwhile, the L2AA-TCN with maximum interlayer spacing exhibits a significantly improved reversible capacity of 121.7 mAh/g (45.0 mAh/g for TCN) at 1.0 A/g. The constructed L2AA-TCN//NVP sodium-ion battery (SIB) displays excellent cycle stability with the capacity-retention of 96.6 % after 200 cycles at 10 C. This work opens a new way to broaden interlayer spacing and hinder enormous volume variation of 2D layered MXenes.

Deciphering Sodium-Ion Storage: 2D-Sulfide versus Oxide Through Experimental and Computational Analyses.

Transition metal derivatives exhibit high theoretical capacity, making them promising anode materials for sodium-ion batteries. Sulfides, known for their superior electrical conductivity compared to oxides, enhance charge transfer, leading to improved electrochemical performance. Here, a hierarchical WS2 micro-flower is synthesized by thermal sulfurization of WO3. Comprising interconnected thin nanosheets, this structure offers increased surface area, facilitating extensive internal surfaces for electrochemical redox reactions. The WS2 micro-flower demonstrates a specific capacity of ≈334mAhg-1 at 15mAg-1, nearly three times higher than its oxide counterpart. Further, it shows very stable performance as a high-temperature (65°C) anode with ≈180mAhg-1 reversible capacity at 100mAg-1 current rate. Post-cycling analysis confirms unchanged morphology, highlighting the structural stability and robustness of WS2. DFT calculations show that the electronic bandgap in both WS2 and WO3 increases when going from the bulk to monolayers. Na adsorption calculations show that Na atoms bind strongly in WO3 with a higher energy diffusion barrier when compared to WS2, corroborating the experimental findings. This study presents a significant insight into electrode material selection for sodium-ion storage applications.

Waste tire-derived graphene modified carbon as anodes for sodium-ion batteries

The rational disposal of waste tires poses a ubiquitous challenge globally. Pyrolytic carbon black, a solid by-product produced through pyrolysis, has great application prospects. Carbon-based materials are regard as the most potential commercial anode materials for sodium-ion batteries (SIBs)， which features cheap, environmentally friendly, and low reaction potential. In this study, three-dimensional vertical graphene composite (TCBp@VGSs) was synthesized from waste tires. The graphene with higher defectiveness offers an increased number of active sites for Na+, while the vertically aligned graphene facilitates rapid electron transfer. As a result, the TCBp@VGSs electrode demonstrates the ability to maintain a reversible capacity of 252.7 mAh g−1 after 100 cycles at a current density of 0.2 A g−1. Furthermore, it exhibits a sustained rate performance of 105.4 mAh g−1 at a current density of 5 A g−1. Moreover, even after 1900 cycles at a current density of 1 A g−1, a reversible capacity of 171.5 mAh g−1 is retained, showcasing good stability and a significantly higher capacity compared to TCBp-1100. This study introduces novel approaches for the high-value utilization of solid-phase by-products from waste tires, offering certain economic benefits, and contributes fresh insights into the advancement of SIBs anodes.

Overview of coals as carbon anode materials for sodium-ion batteries

Abstract Energy storage is an important technology in achieving carbon-neutrality goals. Compared with lithium-ion batteries, the raw materials of sodium-ion batteries are abundant, low-cost, and highly safe. Furthermore, their costs are expected to be further reduced as large-scale applications take off, making them viable for energy storage applications. The primary anode material for sodium-ion batteries is hard carbon, which has a high sodium-ion storage capacity but is relatively expensive, limiting its applications in energy storage. In order to widen the applications of sodium-ion batteries in energy storage and other fields, it is particularly important to develop anode materials that have both high performance and low cost. Coals, with abundant reserves and worldwide availability, can serve as low-cost carbon sources for anode materials. Additionally, coals of different grades of metamorphism have different structural characteristics that can be tailored for the structural characteristics of coal-based anode materials for sodium-ion batteries. Recent research on tailoring coals as the anode materials for sodium-ion batteries is summarized and the recent progress made towards mitigating the existing issues is analysed in this review. Specifically, the impacts of different grades of metamorphism on the sodium-ion storage performance of coal-based anode materials prepared using direct carbonization are discussed in detail. Studies on improving the electrochemical performances of coal-based anode materials through pore and microcrystalline structure controls and surface as well as interface modifications are presented. Finally, the advantages and disadvantages of different preparation methods are identified. To make the industrial applications of coal-based anode materials for sodium-ion batteries more viable, the importance of the de-ashing process is introduced.

Pristine and defective 2D SiCN substrates as anode materials for sodium-ion batteries

Exploring more high-performance anode materials for sodium-ion batteries (SIBs) can smoothly help to build a more sustainable, cleaner, and reliable energy system. This study systematically investigates the potential of 2D pristine SiCN (p-SiCN) and defective (d-SiCN) substrate as candidate materials for SIBs anodes using first-principles computational method. The computational results reveal that the p-SiCN possesses excellent thermal stability and structural cyclical performance, good conductivity, high theoretical specific capacity (1486 mAh·g−1), low diffusion barrier (0.177 eV), and appropriate open-circuit voltage (0.340 V), which allows the p-SiCN substrate more suitable as a potential anode material for SIBs. Furthermore, by investigating the effects of intentionally designed defects on p-SiCN, it is observed that the adsorption energy and diffusion barrier of the Na atom on the d-SiCN substrate increase. Our work demonstrates that investigating the effect of defects on p-SiCN can better explore the properties of anode materials, thus further optimizing the battery performances.