Anode For Sodium-ion Batteries Research Articles

Ni2P/Cu3P bimetallic phosphide embedded in nitrogen-doped carbon as SIB anode: Constructed hetero interface promoting fast Na+ diffusion and storage performance

Transition metal phosphides (TMPs) have attracted widespread attention as electrode materials for sodium-ion batteries (SIBs) due to their high theoretical specific capacity, various bonding types, metallic characteristics, and low cost. However their sluggish reaction kinetics and inferior capacity decay severely hamper their application. Designing TMPs with novel nano/microstructures effectively overcomes these challenges. Herein, Nickel Phosphide/Copper Phosphide embedded in nitrogen-doped carbon (Ni2P/Cu3P@NC) was synthesized by carbonization and phosphidation process. When used as an SIB anode, Ni2P/Cu3P@NC exhibited a reversible specific capacity of 530 mAh/g after 200 cycles at 0.2 A/g, 428 mAh/g after 1000 cycles at 1.0 A/g, and good rate capability (334 mAh/g at 2.0 A/g). Ex-situ XRD combined with in-situ EIS confirm the irreversible conversion mechanism. Density Functional Theory (DFT) calculations show that the heterointerface formed between Ni2P and Cu3P serves as a channel for fast ion delivery and promotes Na+ storage performance. Furthermore, the practical application was further investigated by assembling Ni2P/Cu3P@NC//Na3V2(PO4)3 full cells.

Construction of MnS nanocubes confined in N, S co-doped carbon as high-performance anodes for sodium-ion batteries

Profiting from the huge natural abundance and high theoretical capacity, manganese sulfides (MnS) have triggered abundant interest and attention, which are expected as highly prospective anodes for sodium-ion batteries (SIBs). Nevertheless, their wide utilizations are seriously impeded by the drawbacks of low electric conductivity, extensive volumetric changes, and sluggish insertion/extraction kinetics, which often result in a rapid deterioration of the capacity and cyclic lifespan for SIBs. Herein, MnS nanocubes confined in N, S co-doped carbon (NSC) matrix are manufactured through a simple hydrothermal with the following sulfurization method. The incorporation of carbon improves the electric conductivity to accelerate electron transport and guards the structural integrality of MnS in the long-term cycling process via the confinement effect. The in situ formed sulfur-bridged bonds (C-S-Mn) provide an intimate affinity between the MnS nanocubes and NSC matrix, which effectively prevents the aggregation and mitigates the volumetric variation of MnS nanocubes in the sodiation/desodiation reactions. Moreover, the hierarchically porous structures in MnS@NSC offer rapid diffusion pathways for Na+ ions that effectively enhance the diffusion kinetics. Benefiting from the admirable synergistic effects between the hierarchically porous MnS nanocubes and conductive NSC framework, the MnS@NSC anode delivers satisfied sodium storage properties.

Bamboo waste derived hard carbon as high performance anode for sodium-ion batteries

Biomass-derived hard carbon stands out as one of the most promising anode materials for advancing the commercial viability of sodium-ion batteries (SIBs). In this study, we harnessed a straightforward and eco-friendly two-step carbonization approach to fabricate high-performance hard carbon materials, ingeniously repurposing industrial bamboo waste. Concurrently, we delved into the impact of carbonization temperature on the microstructure and properties of the hard carbon derived from bamboo waste. The findings revealed that the as-prepared hard carbon at 1400 °C (HCB-1400) showcased the most desirable sodium-ion storage capabilities. The HCB-1400 material not only can deliver a substantial reversible capacity of 328.4 mAh g−1 at 30 mA g−1 in its maiden charge-discharge cycle but also display remarkable cycling stability. Moreover, the HCB-1400//Na3V2(PO4)3 full cell, when assembled, exhibited an impressive energy density of 249.25 Wh kg−1, with a capacity retention rate of 93 % after enduring 200 cycles at a current density of 1.0 C. This research underscores the potential of transforming biomass waste into high-performance hard carbon, heralding a sustainable path for SIB applications.

MIL-88-derived porous carbon rod-supported FePS3 nanosheet arrays for robust sodium storage

Ternary metal phosphorus trisulfide (MPS3) has emerged as an excellent candidate for use as an anode in sodium-ion batteries, characterized by its unique layered structure, easily tunable physicochemical properties, and high theoretical capacity. However, its intrinsic challenges such as low electrical conductivity and susceptibility to fragmentation have led to unsatisfactory rate and cyclic capability. Herein, the intriguing microcomposite structure of porous carbon rod-supported FePS3 nanosheet arrays (FePS3@CR) is ingeniously constructed in situ via the phospho‑sulfurization of MIL-88. FePS3@CR showcases multiple structural advantages, including enhanced electrical conductivity, increased surface area, accelerated electron transfer rate, and mitigated structural stress. These combined benefits endow FePS3@CR with improved rate capability (808.0 and 474.3 mAh g−1 at 0.1 and 10 A g−1, respectively) and cyclic life (94.5 % retention after 1500 loops at 2 A g−1). The assembled full battery also demonstrates robust cycling stability, retaining 94.2 % of its capacity after 1100 loops at 0.5 A g−1. The specific sodium storage process of the FePS3 electrode is investigated through ex-situ structure analysis. This work presents innovative structural designs potentially improving the energy storage performance of MPS3 material system.

Structural regulation and sodium storage mechanism of high-performance non-graphitic carbon derived from semi coke

Non-graphitic carbon (NGC) is considered as one of the most promising anodes for sodium-ion batteries (SIBs) because of its low cost and abundant reserves. Nevertheless, there is significant debate regarding the contribution mechanism of sloping and plateau capacity. Herein, a series of NGC with adjustable defect concentration, carbon phases and pore structure are synthesized with semi-coke as precursor to explore the sodium storage mechanism and an “adsorption-insertion-filling” model is proposed based on the in-depth analysis of microstructure and electrochemical behaviors. The very attraction about this work is that the entire discharge curve is divided into three regions for analysis, and the corresponding cause for each region is traced. To be specific, the defects and disordered structure contribute to the surface-controlled absorption behavior in the sloping region >0.1 V, the pseudo-graphitic structure shows diffusion-controlled insertion behavior in the plateau region between 0.1 and 0.05 V, and the closed pores formed by curved graphite-like structure provide plateau capacity (<0.05 V) through the filling of quasi-metallic sodium. This study provides theoretical education for the optimization of NGC anode structure and a novel approach for the excessive value-added utilization of semi coke.

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

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

Uncovering the Salt-Controlled Porosity Regulation in Coal-Derived Hard Carbons for Sodium Energy Storage.

Coal is a promising precursor of hard carbon (HC) anodes for sodium-ion batteries (SIBs), by virtue of resource abundance, low cost, and high product yield. However, the concomitant inorganic salt is usually recognized as impurities and plays an obscure and even contradictory effect on the regulation of pore structure in HCs. Herein, a two-step pyrolysis procedure to the representative salty coal is performed, in which the acid washing program is selectively inserted. It is illuminated that salt acts as a template or activating agent for the generation of open pores at low temperatures but inhibits the closure of pores during the following high-temperature carbonization. The optimized HC delivers a reversible capacity of 322.4 mAh g-1, a high plateau capacity of 192 mAh g-1, and an initial coulombic efficiency of 80%, outperforming to most coal-based HCs. Assembled with an NVPOF cathode, the full-cell exhibits a high energy density of 284.7 Wh kg-1. This work not only provides a systematic understanding of salt-dependent pore structure modulation but also practices a simple, cost-effective, and potentially scalable technique for the production of coal-based HCs.

Gravure-Printed Anodes Based on Hard Carbon for Sodium-Ion Batteries

Printed batteries are increasingly being investigated for feeding small, wearable devices more and more involved in our daily lives, promoting the study of printing technologies. Among these, gravure is very attractive as a low-cost and low-waste production method for functional layers in different fields, such as energy, sensors, and biomedical, because it is easy to scale up industrially. Thanks to our research, the feasibility of gravure printing was recently proved for rechargeable lithium-ion batteries (LiBs) manufacturing. Such studies allowed the production of high-quality electrodes involving different active materials with high stability, reproducibility, and good performance. Going beyond lithium-based storage devices, our attention was devoted on the possibility of employing highly sustainable gravure printing for sodium-ion batteries (NaBs) manufacturing, following the trendy interest in sodium, which is more abundant, economical, and ecofriendly than lithium. Here a study on gravure printed anodes for sodium-ion batteries based on hard carbon as an active material is presented and discussed. Thanks to our methodology centered on the capillary number, a high printing quality anodic layer was produced providing typical electrochemical behavior and good performance. Such results are very innovative and relevant in the field of sodium-ion batteries and further demonstrate the high potential of gravure in printed battery manufacturing.

Structure Regulation and Energy Storage Mechanisms of Bismuth‐Based Anodes for Sodium Ion Batteries

The increasing demand for eco‐friendly energy storage solutions has driven significant interest in sodium‐ion batteries (SIBs) as an alternative to lithium‐ion batteries, primarily due to sodium's abundant availability. Among various anode materials, bismuth (Bi) has emerged as a promising candidate due to its high theoretical volumetric capacity and excellent electrical conductivity. This review presents a comprehensive analysis of structural characteristics and failure mechanisms inherent to Bi‐based anode materials for SIBs, providing valuable insights into the significance of material modification methods. Structure regulation strategies for Bi‐based SIB anodes are reviewed, focusing on the challenges associated with volumetric expansion and strategies to enhance their electrochemical performance. Typically, nanostructure optimization, surface engineering, morphology modification, and composition regulation are highlighted. Furthermore, this review will discuss the underlying mechanisms that improve sodium storage capabilities and the role of bismuth in advancing the efficiency and stability of SIBs. Lastly, the prospects and imminent challenges associated with bismuth‐based materials will be presented, providing insights for future research and development in energy storage technologies.

Multifunctional Effect of Carbon Matrix with Sulfur Dopant Inspires Mixed Metal Sulfide as Freestanding Anode in Sodium-Ion Batteries.

As active materials for large-radius Na+ storage, metal sulfide (MS) anodes still face several challenges, including poor intrinsic electric conductivity, severe volume change along with the shuttle and dissolution effects of discharge-produced polysulfides. In this work, the mixed nickel-manganese sulfides (NiMnS) in the morphology of uniform 2D ultrathin nanosheets are derived from layered metal-organic frameworks (MOFs), where the NiS-MnS heterojunction are accommodated in carbon matrix with S dopant (NiMnS/SC). Through experiments and density functional theory (DFT) simulations, it is revealed that the carbon matrix with S dopant has multifunctional effects on active NiMnS during the charge/discharge process, including conductive intermediary, electrochemical active site, physical barrier, and chemical adsorption. This work may promote the design of MS-based electrodes in SIBs and extend the application of carbon material with S dopant in Na-S batteries.

Novel Q-Carbon Anodes for Sodium-Ion Batteries

The lack of a standard anode for sodium-ion batteries (SIBs) has greatly hindered their applications. Herein, we show that a novel phase of carbon, namely Q-carbon, is an effective anode material for sodium-ion batteries. The Q-carbon, which is a metastable phase of carbon consisting of about 80% sp3- and 20% sp2-bonded carbon, is synthesized by nonequilibrium pulsed laser annealing and arc-discharge methods. Two types of Q-carbons, Q1 and Q2, were evaluated as anode material for SIBs. Q1 had a slow quench and was used as the control, whereas Q2 was Q-carbon with a rapid quenching. Q1 exhibits a high initial columbic efficiency of 81% and a low-capacity retention of less than 60%, whereas Q2 has a low initial columbic efficiency of 58% and a high-capacity retention of 81%. Q2 exhibits a stable capacity of 168 mAh·g−1 at a cycling rate of C/3 (124 mA·g−1), which is comparable to other hard carbon anodes reported in the literature. This unique synthesis method opens a pathway for the further tuning of Q-carbon with higher trapping/charging of Na+ ions in improved SIBs.

Self-Template Construction of Hierarchical Bi@C Microspheres as Competitive Wide Temperature-Operating Anodes for Superior Sodium-Ion Batteries.

Huge volume changes of bismuth (Bi) anode leading to rapid capacity hindered its practical application in sodium-ion batteries (SIBs). Herein, porous Bi@C (P-Bi@C) microspheres consisting of self-assembled Bi nanosheets and carbon shells were constructed via a hydrothermal method combined with a carbothermic reduction. The optimized P-Bi@C-700 (annealed at 700 °C) demonstrates 359.8 mAh g-1 after 1500 cycles at 1 A g-1. In situ/ex situ characterization and density functional theory calculations verified that this P-Bi@C-700 relieves the volume expansion, facilitates Na+/electron transport, and possesses an alloying-type storage mechanism. Notably, P-Bi@C-700 also achieved 360.8 and 370.3 mAh g-1 at 0.05 A g-1 under 0 and 60 °C conditions, respectively. Na3V2(PO4)3//P-Bi@C-700 exhibits a capacity of 359.7 mAh g-1 after 260 cycles at 1 A g-1. These hierarchical microspheres effectively moderate the volume fluctuation, preserving structural reversibility, thereby achieving superior Na+ storage performance. This self-template strategy provides insight into designing high-volumetric capacity alloy-based anodes for SIBs.

In-situ construction of heterogeneous structure by crystal phase evolution to improve the sodium storage performance of NiCo2O4

Transition metal oxides (TMCs) have great potential in sodium ion batteries (SIBs) due to their significantly higher capacity and lower cost. However, during the cycle, huge volume changes often lead to structural damage, which is a key factor in the rapid decay of capacity. In this paper, a heterogeneous structure was constructed in situ by introducing sulfur element to induce the decomposition of NiCo2O4 crystal phase. The rich heterogeneous interface has enhanced redox reaction kinetics and charge transport properties. For high-capacity conversion anode materials, cross-linked grain boundaries can effectively disperse the local stress caused by volume changes and alleviate the inevitable electrode crushing, thus ensuring the stability of the electrode during long-term cycling. The NiCo2O4/NiCo2S4/CoO/ NiO heterogeneous structure (NCOS-350) exhibits enhanced cycling and rate performance (350 mAh g−1 at 0.5 A g −1 after 100 cycles and 270 mAh g −1 at 5 A g −1) when used as the anode for sodium ion batteries. In addition, it is proved that NCOS-350 has smaller volume change and better structural stability than NiCo2O4 by scanning electron microscopy and other characterizations.

Understanding pillar chemistry in potassium-containing polyanion materials for long-lasting sodium-ion batteries

K-containing polyanion compounds hold great potential as anodes for sodium-ion batteries considering their large ion transport channels and stable open frameworks; however, sodium storage behavior has rarely been studied, and the mechanism remains unclear. Here, using a noninterference KTiOPO4 thin-film model, the Na+ storage mechanism is comprehensively revealed by in situ/operando spectroscopy, aberration-corrected electron microscopy and density functional theory calculations. We find that incomplete K+/Na+ ion exchange occurs and eventually 0.15 K+ remains as a pillar to stabilize the tunnel structure. The pillar effect substantially maintains the volume change within 3.9%, much smaller than that of K+(Na+) insertion into KTiOPO4(NaTiOPO4) (9.5%; 5%), thus enabling 10,000 cycles. The powder electrode demonstrates comparable capacity and can work efficiently at commercial-level areal capacity of 2.47 mAh cm−2. The quasi-solid-state pouch cell with high safety under extreme abuse also manifests long-term cycling stability. This pillar chemistry will inspire alkali metal ion storage in hosts containing heterogeneous cations.

DFT-Guided Design of Dual Dopants in Anatase TiO2 for Boosted Sodium Storage.

Anatase titanium dioxide (TiO2) has drawn great attention as an anode material in sodium ion batteries (SIBs), but it suffers from the sluggish diffusion kinetics of Na+ within TiO2 and inferior electronic conductivity. Herein, under the guidance of density functional theory (DFT), we propose a nitrogen and selenium dual-doped TiO2 system as an advanced SIB anode. Both DFT and experimental investigations reveal the cooperative effect of dopants in boosting the electrochemical performance of TiO2, finding the optimal content ratio (N/Se at 1:3) for overall improved SIB performances. As expected, experimental results exhibit excellent sodium storage behavior of the N,Se-doped TiO2, including high discharge capacity (142 mAh g-1 at 2 A g-1), good rate performance (82 mAh g-1 at 20 A g-1), and ultralong cyclability (97% retention over 5000 cycles at 2 A g-1). Our study underscores the importance of dual-heteroatom doping in the rational design of advanced electrode materials.

(Fe, Co) oxide nanowires on gold nanoparticles modified MOF-derived carbon nanoflakes for high-efficiency sodium-ion batteries and supercapacitors across electrolytes

The three-dimensional conductive porous carbon nanosheets (CPCN) are from the bimetallic metal-organic framework (MOFs) consisting of organic ligating groups that incorporate zinc and cobalt ions deposited onto a flexible carbon cloth (CC). Utilizing a hydrothermal approach, iron-cobalt oxide (FCO) nanowires are intricately embedded onto CPCN modified with gold (Au), forming a flexible FCO/Au/CPCN@CC electrode. The electrochemical characteristics of electrodes are evaluated in 1 M Na2SO4, supercapacitor's storage capacity is tested at 4 V using 1 M NaPF6 electrolyte. Among its remarkable attributes are a peak energy density of 291.5 W h kg−1 achieved at a power density of 153.85 W kg−1, and even at the maximum power density of 1749.9 W kg−1, it maintains 144.78 W h kg−1. Undergoing 10,000 rounds of GCD, the equipment sustains a capacitance retention of 84.27 %. Moreover, the performance of the FCO/Au/CPCN@CC anode in sodium-ion batteries (SIBs) is assessed. At 0.1C, the discharge capacity reaches 958 mAh g−1, and there is almost no loss after the rate cycle. The Coulomb efficiency surpasses 98 % during 500 cycles at a large C-rate. The integration of Au nanoparticles onto the CPNC surface enhances the energy storage characteristic of the FCO/Au/CPCN@CC composite material in both battery and supercapacitor applications.

Electrolyte Reconfiguration by Cation/Anion Cross-coordination for Highly Reversible and Facile Sodium Storage.

Hard carbon (HC) materials are promising anodes for sodium-ion batteries (SIBs) owing to low cost, high specific capacity and low working potential. However, the poor compatibility of the electrolyte with HC leads to low initial coulombic efficiency (ICE) and sluggish Na+ transport kinetics. Here, we propose an electrolyte reconfiguration strategy based on the hard and soft acid and base (HSAB) theory by introducing methyltriphenylphosphonium bromide (MTPPB). MTPPB can realize a spontaneous cross-coordination solvation structure with NaPF6 by selective affinity, synchronously optimizing the interfacial chemistry and sodium storage process. The advantages of the chemical π-π bridging of MTPP+-HC and interaction of MTPP+-PF6- contribute to preferential and oriented reduction of PF6-, forming a low-resistance supramolecular SEI. Additionally, Na+-Br- coordination weakens the Na+-solvent interactions, facilitating Na+ de-solvation kinetics. Consequently, the HC||Na cell achieves a superior ICE of 96.6%, desirable rate capability under 25 °C and invisible capacity decay after 500 cycles at 1 C under -20 °C. The Na4Fe3(PO4)2P2O7||HC pouch battery displays a high ICE of 90.3% and a 15% increment of energy density under 25 °C. This work provides a guidance through electrolyte reconfiguration engineering for designing practical HC-based SIBs with high energy/power density and long-life span in the extended operating-temperature range.

The Research About Anode Material for Sodium-Ion Batteries

Sodium-ion batteries are replacing lithium-ion batteries due to their lower cost and more abundant resources. The sodium-ion battery anode, including carbon-based materials, alloy materials, and organic materials, plays a key role in improving battery performance but also faces problems such as poor conductivity, which limits sodium storage capacity attenuation and irreversible volume expansion. To solve these problems, researchers have proposed a variety of solutions, such as chemical activation, element doping, micro-nanostructure design, composite material preparation, surface coating application, and buffer medium introduction. This article summarizes these strategies and points out the direction of future research, including the development of innovative anode materials with better conductivity and sodium storage capacity, and improved manufacturing processes. Further research and development of sodium-ion batteries anode is expected to make important contributions to the new energy field.

Conversion of waste denim fabrics into high-performance carbon fiber anodes for sodium-ion batteries

Conversion of waste denim fabrics into high-performance carbon fiber anodes for sodium-ion batteries

Evidence of Quasi-Na Metallic Clusters in Sodium Ion Batteries through In Situ X-Ray Diffraction.

Carbonaceous materials have been considered the most promising anode in sodium-ion batteries (SIBs) due to their low cost, good electrical conductivity, and structural stability. The main challenge of carbonaceous anodes prior to their commercialization is low initial coulomb efficiencies, derived from a lack of an efficient technique to reveal a fundamental comprehension of sodium storage mechanisms. Here, the direct observation of quasi-Na metallic clusters in carbonaceous anodes during cycling through in situ XRD is reported. By means of such a technique, a strong self-adsorption behavior forming quasi-Na metallic clusters is detected within a rationally designed highly defective ultrathin carbon nanosheets (HDCS) anode. Such a self-adsorption and crystalline system transformation mechanism in HDCS brings capacity retention about 100% after 1000 cycles at 1 A g-1. This work provides a new principle for designing high-performance carbon anodes for SIBs.