Sodium Storage Capacity Research Articles

A multichambered carbon based electrode materials to realize efficient sodium-ion batteries

Sodium-ion batteries (SIBs) have emerged as a compelling alternative to lithium-ion counterparts, owing to the widespread availability and low cost of sodium. However, to achieve successful commercialization, the development of a high-performance electrode material is crucial. This study presents a facile synthesis strategy for the production of multichambered carbon cubes (MCCs) derived from ZIF-8 precursors. The optimized process mesoporous MCCs which were then embedded with zinc selenide (ZnSe@MCCs) for the anode and infused with sulfur (S@ZnSe@MCCs) to create the cathode of SIBs. The uniform, hierarchically porous MCC morphologies enable deep electrolyte penetration, unlocking the full potential of these electrode materials. SIBs utilizing ZnSe@MCCs anodes exhibited impressive sodium storage capacities (exceeding 300 mAh g−1 after 1000 cycles) and rate capabilities. Moreover, when employed as the cathode, the S@ZnSe@MCCs effectively suppressed the polysulfide shuttle phenomenon. The performance of these sodium-ion cells underscores the potential of MCCs to enable high capacity, long cycle life, and fast kinetics, paving the way for practical and efficient sodium-ion battery technologies.

Facile synthesis of in situ carbon-coated CoS2 micro/nano-spheres as high-performance anode materials for sodium-ion batteries.

In situ carbon-coated CoS2 micro/nano-spheres were successfully prepared by sulfuric calcination using the solvothermal method with glycerol as the carbon source without introducing extraneous carbon. This method prevents carbon agglomeration and avoids the cumbersome steps of the current technology. The composite demonstrates excellent sodium storage capacity as an anode material for sodium-ion batteries. The initial charge and discharge capacities were 1027 and 1224 mA h g-1 at 50 mA g-1, respectively, with an initial coulombic efficiency of 83.9%. The capacity of CoS2@C at 350 °C was maintained at 937 mA h g-1 after 140 cycles at a current density of 2 A g-1. The outstanding electrochemical performance is mainly attributed to the nanostructure design and the presence of in situ carbon. As revealed by the kinetic analysis, the pseudo-capacitive behaviour also contributed to the excellent electrochemical performance.

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.

Reduced Na–S bond adsorption of WSSe enabling fast reaction kinetics in the sodium-ion battery

WS2, a two-dimensional layered material, is promising as sodium-ion batteries (SIBs) anode due to its large interlamellar spacing and high sodium storage capacity. However, its low electronic conductivity and high Na+ adsorption energy hinder reaction kinetics. Here we demonstrate that substituting Se for part of the S in WS2 reduces interlayer Na+ adsorption and increases electronic conductivity. Based on this finding, lamellar WSSe, grown in situ on peanut shell-derived carbon (PSDC/WSSe), is elaborately designed as a highly stable SIB anode with a fast kinetic. PSDC/WSSe with carbon matrix and Se substitution simultaneously provides fast electron transport channels and lowered Na+ transport barriers (0.22 eV). The PSDC/WSSe anode offers a considerable reversible sodium storage capacity (288.0 mAh g−1 after 1000 cycles at 1.0 A g−1) and a fast kinetic reaction. A SIB full-cell using a PSDC/WSSe anode and Na3V2(PO4)3 cathode achieves a 215.4 Wh kg−1 high energy density, and successfully powers LEDs. This work offers new strategies to lower sodium ion transportation barrier in two-dimensional layered materials.

Ball-Milling-Assisted N/O Codoping for Enhanced Sodium Storage Performance of Coconut-Shell-Derived Hard Carbon Anodes in Sodium-Ion Batteries.

Sodium-ion batteries (SIBs) are regarded as cost-effective alternatives or competitors to lithium-ion batteries for large-scale electric energy storage applications. However, their development has been hindered by the high cost of hard carbon (HC) anodes and poor electrochemical performance. To enhance the sodium storage capacity and rate performance of HC, this study accelerated the electrochemical performance of coconut-shell-derived HC anodes for SIBs through N/O codoping using ball milling and pyrolysis. Experimental results demonstrate that the simultaneous introduction of N and O generates a synergistic effect, increasing the surface oxygen-containing functional groups, defects, and interlayer spacing of coconut-shell-derived HC through the codoping of light elements. The excellent strategy has increased the slope capacity and platform capacity of HC, and the synergistic modification of N/O has increased its reversible specific capacity from 272 to 343 mA h g-1 (30 mA g-1), with a retention rate of approximately 92.1% after 100 cycles. In addition, it also exhibits an excellent rate performance, reaching 178 mA h g-1 at 1500 mA g-1. In summary, this study presents an effective strategy for modifying biomass-derived HC.

Core‐Shell Structured CoP@C Cubes as a Superior Anode for High‐Rate and Stable Sodium Storage

AbstractTransition metal phosphides have emerged as a class of promising anode materials of sodium‐ion batteries owing to their excellent sodium storage capacity. However, the limited electronic conductivity and significant volume expansion have impeded their further advancement. In this work, we propose a rational design of cube‐like CoP @C composites with unique core‐shell structure via in situ phosphating and subsequent carbon coating processes. The uniform carbon coating serves as a physical buffering layer that effectively mitigates volume changes during charge/discharge processes, and prevents particle agglomeration and fragmentation, thereby enhancing the structural stability of electrode. Moreover, the nitrogen‐rich carbon layer not only provides additional active sites for sodium ion adsorption but also improves the electrode conductivity and accelerates charge transport dynamics. Consequently, the as‐synthesized CoP@C exhibits a remarkable capacity retention rate of 94.8 % after 100 cycles at 0.1 A g−1 and achieves a high reversible capacity of 146.7 mAh g−1 even under a high current density of 4.0 A g−1.

Biomass-derived hard carbon material for high-capacity sodium-ion battery anode through structure regulation

Economical and environmentally friendly hard carbon materials are attractive options for high-performance sodium-ion battery anode materials. Biomass-derived hard carbon materials have good economic benefits and environmentally friendliness as anode materials for sodium-ion batteries. In this work, we propose a new hard carbon material prepared from agricultural waste olive shells through a simple and environmentally friendly process. The effects of high-temperature treatments and pre-carbonization strategies on the pore structure and graphitization degree of the hard carbon materials were investigated. Combined with electrochemical performance tests, the influence of structural changes on the sodium storage properties of the olive shell-derived hard carbon was revealed. Under the optimized conditions of carbonization temperature and pre-carbonization strategy, the OSHC-Air electrode exhibits excellent sodium storage capacity with 87 % capacity remaining after 1000 cycles at 1000 mA g−1. The assembled PB//OSHC-Air sodium-ion full cell exhibits a high capacity of 216 mAh g−1. Our research provides a potential candidate for commercial anode materials for high-capacity sodium-ion batteries.

Cu2-xSe@MXene (Ti3C2Tx) 2D layered heterostructure as an anode for high-performance sodium-ion batteries

With a notable focus on developing efficient sodium storage electrode materials, sodium-ion batteries (SIBs) have been identified as a promising contender in the pursuit of high-performing substitutes for lithium-ion batteries. Among varying sodium storage anode materials for SIBs, nonstoichiometric Cu2-xSe exhibits significant promise. This material stands out due to its ultrahigh electrical conductivity and theoretical sodium storage capacity. However, the practical implementation of Cu2-xSe-based anodes in SIBs is significantly impeded by their sluggish electrochemical reaction kinetics and severe pulverization during the repeated charge–discharge cycles. In the current research, we introduce a novel and straightforward methodology for the synthesis of a heterostructured SIBs anode material (Cu2-xSe@Ti3C2Tx), by coupling Cu2-xSe nanoparticles with two-dimensional (2D) layered MXene (Ti3C2Tx). The 2D layered Ti3C2Tx can provide abundant fast Na+ transport pathways, which effectively promote the ion transport kinetics in the composite anode. Moreover, the pulverization of Cu2-xSe can be effectively mitigated due to the interlamellar spatial confinement of the 2D layered MXene matrix. Consequently, the electrochemical performances of the Cu2-xSe-based anode are significantly improved. Concretely, the Cu2-xSe@Ti3C2Tx anodes demonstrate remarkable rate performance (248mAh g−1 at 10.0 A/g), along with commendable cycling stability, exhibiting a capacity retention of 92 % at 5.0 A/g after 750 cycles. A comprehensive assessment of the Cu2-xSe@Ti3C2Tx anode has been conducted by assembling a full SIB alongside a Na3V2(PO4)3 cathode. This comprehensive study underscores the significant potential of Cu2-xSe-based composite materials, positioning it as a promising candidate for future advancements in SIB technology.

Unraveling the enhanced sodium-storage mechanism in a strongly bonded 2D honeycomb borophene/boron phosphide heterostructure

The growing modern demand for battery capacity is driving the development of high-capacity metal-ion battery anodes for future energy storage. Two-dimensional (2D) material-based heterostructures have shown advantages as alternative anodes due to their enhanced adsorption capacity. The lightweight nature of honeycomb borophene (HB) is beneficial for serving as a high-capacity anode but is constrained by structural instability arising from electron deficiency. In this study, using first-principles calculations, we propose a HB/boron phosphide (BP) heterostructure as an anode for both lithium-ion batteries and sodium-ion batteries (SIBs). The heterostructure engineering not only stabilizes the HB structure but also leads to a bonding heterostructure instead of common van der Walls type. The HB/BP demonstrates robust structural stability and reversibility when multiple ions are stored. In addition, the HB/BP offers stable storage sites and low diffusion barriers for lithium (0.31 eV) and sodium (0.28 eV), indicating rapid charging–discharging performance. Notably, the predicted maximum sodium storage capacity reaches 2402 mAh/g, surpassing that of the constituent monolayers and most 2D heterostructures. The underlying mechanism for high storage capacity is elucidated through detailed charge image model analysis, offering atomistic-scale insights for constructing high-capacity anodes. All results suggest that the presented HB/BP is a promising anode candidate for SIBs and opens an avenue for stabilizing HB in energy storage.

Steric Hindrance Engineering to Modulate the Closed Pores Formation of Polymer-Derived Hard Carbon for High-Performance Sodium-Ion Batteries.

The closed pores play a critical role in improving the sodium storage capacity of hard carbon (HC) anode, however, their formation mechanism as well as the efficient modulation strategy at molecular level in the polymer-derived HCs is still lacking. In this work, the steric hindrance effect has been proposed to create closed pores in the polymer-derived HCs for the first time through grafting the aromatic rings within and between the main chains in the precursor. The experimental data and theoretical calculation demonstrate that steric-hindrance effect from the aromatic ring side group can increase backbone rigidity and the internal free volumes in the polymer precursor, which can prevent the over graphitization and facilitate the formation of closed pores during the carbonization process. As a result, the as-prepared HC anode exhibits a remarkably enhanced discharge capacity of 340.3 mAh/g at 0.1 C, improved rate performance (210.7 mAh/g at 5 C) as well as boosted cycling stability (86.4 % over 1000 cycles at 2 C). This work provides a new insight into the formation mechanisms of closed pores via steric hindrance engineering, which can shed light on the development of high-performance polymer-derived HC anode for sodium-ion batteries.

Tailoring Pseudo-Graphitic Domain by Molybdenum Modification to Boost Sodium Storage Capacity and Durability for Hard Carbon.

Hard carbon (HC) stands out as the most prospective anode for sodium-ion batteries (SIBs) with significant potential for commercial applications. However, some long-standing and intractable obstacles, like low first coulombic efficiency (ICE), poor rate capability, storage capacity, and cycling stability, have severely hindered the conversion process from laboratory to commercialization. The above-mentioned issues are closely related to Na+ transfer kinetics, surface chemistry, and internal pseudo-graphitic carbon content. Herein, constructing molybdenum-modified hard carbon solid spheres (Mo2C/HC-5.0), both the ion transfer kinetics, surface chemistry, and internal pseudo-graphitic carbon content are comprehensively improved. Specifically, Mo2C/HC-5.0 with higher pseudo-graphitic carbon content provides a large number of active sites and a more stable layer structure, resulting in improved sodium storage capacity, rate performance, and cycling stability. Moreover, the lower defect density and specific surface area of Mo2C/HC-5.0 further enhance ICE and sodium storage capacity. Consequently, the Mo2C/HC-5.0 anode achieves a high capacity of 410.7mA h g-1 and an ICE of 83.9% at 50mA g-1. Furthermore, the material exhibits exceptional rate capability and cycling stability, maintaining a capacity of 202.8mA h g-1 at 2 A g-1 and 214.9mA h g-1 after 800 cycles at 1 A g-1.

A Recyclable Polyimide Derived Hard Carbon as a High‐Performance Negative Electrode Material for Sodium‐Ion Batteries

AbstractHard carbon, characterized by high ion storage capacity, low operating voltage, and excellent cycling stability, is considered an ideal negative electrode material for sodium‐ion batteries. However, the high cost and low carbon yield of thermosetting precursors limit their practical application in SIBs, while low‐cost and high‐yield raw materials exhibit highly ordered carbon structures and narrow interlayer spacing under high‐temperature carbonization. Discarded polyimide materials are inexpensive, which offer a high carbon yield and possess good thermal stability and thermoplasticity, with functional groups of imide rings (−CO−N−CO−) on their main chains. This study recycled and converted polyimide materials into hard carbon materials from discarded engineering plastics, investigating the influence of carbonization temperature on the degree of graphitization, interlayer spacing, and pore structure of the materials to achieve high reversible sodium storage capacity. After carbonization at 1300 °C, the polyimide material exhibited 319 mAh g−1 reversible capacity and excellent electrochemical performance (with a capacity retention of 91.92 % after 100 cycles at a 0.5 C current rate) and rate performance (up to 242.5 mAh g−1 at 2 C). This study provided a simple, high‐yield, and effective method for the reuse of discarded organic polymers, promoting the sustainable utilization of resources.

N/P/O co-doped porous carbon derived from agroindustry waste of peanut shell for sodium-ion storage

Porous bio‑carbon from agroindustry waste behaves one of the most promising anode materials for sodium-ion batteries (SIBs) because of its high sodium storage capacity, low cost, sustainability, and low charge/discharge voltage platform. Herein, we have developed a new N/P/O co-doped porous hard carbon derived from peanut shell (PSCNP) synthesized via KOH activation, hydrothermal doping combined with carbonization method, using chitosan as nitrogen source, phytic acid as phosphorus source, and peanut shell as carbon and oxygen source. Through seriously regulating the calcination temperature, the optimal PSCNP-800 carbonization at 800 °C can well combine the advantages of the natural rich porous microstructure of peanut shells, large graphite interlayer spacing (0.379 nm), and short diffusion distance for sodium-ion. As an advanced anode for SIBs, the PSCNP-800 delivered a reversible capacity of 248.8 mAh g−1 after 100 cycles at 25 mA g−1. This work could provide a possible idea for the preparation of N/P/O co-doped porous hard carbon from low-cost agroindustry waste as anodes for SIBs.

Preparation and sodium storage properties of Ni-CoFe2O4/Reduced graphene oxide

The Ni-doped CoFe2O4 graphene composites (Ni-CFO/RGO) have been successfully prepared using the microwave-assisted method. The substance is a novel nanocomposite structure in which CoFe2O4 nanoparticles are tightly and uniformly attached to graphene hybrid nanosheets. The synergistic effect of Ni doping and CoFe2O4 can reduce the volume expansion of CoFe2O4 in the reaction process and inhibit the stacking of graphene. Because the Ni-CFO/RGO composite is structurally stable during the electrochemical reaction, it has a good theoretical capacity. Excellent carbon composite can further enhance the electron transport performance and structural stability of the material, thereby improving the electrochemical performance and cycle life of the material. Doping Ni2+ into metal oxides can not only form oxygen vacancies, and improve the transport capacity of sodium ions, but also broaden the electron transport channel. In addition, the catalyst can form a composite structure with metal oxide, which can effectively inhibit its volume expansion. At the same time, reacting with carbon materials, can also effectively reduce the accumulation of carbon, thereby reducing its resistance. After 200 cycles at a current density of 0.05 A g−1, it can provide a high sodium storage capacity of 380.6 mAh g−1, which still keeps 203.4 mAh g−1 at 1.5 A g−1.

From Natural Fibers to High-Performance Anodes: Sisal Hemp Derived Hard Carbon for Na-/K-Ion Batteries and Mechanism Exploration.

Hard carbon (HC) is a promising anode material in alkali metal ion batteries owing to its cost-effectiveness, abundant sources, and low working voltage. However, challenges persist in achiving prolonged cycling stability and consistent capacity, and the sodium storage mechanism in HC is still debated. Herein, an unreported biomass precursor, "sisal," for deriving hard carbon is developed. A series of sisal hemp-derived hard carbon with natural 3D porous channels are prepared. Through phase characterization and electrochemical testing, the relationship between microstructure and sodium storage capacity is elucidated, further confirming the suitability of the "adsorption-insertion-filling" mechanism for sodium storage properties in hard carbon materials. Without the need for any additional modification strategies, this biomass-derived hard carbon demonstrates excellent electrochemical performance in both sodium-ion and potassium-ion batteries (SIBs and PIBs). The as-prepared HC-1300 demonstrates excellent ion storage capability, delivering a high reversible capacity of 345.2mAhg-1 in SIBs and 310mAhg-1 in PIBs at 0.1C. Moreover, it maintains a specific capacity of 237.3mAhg-1 over 1200 cycles at 1C when used in SIBs. The excellent cycling stability and superior rate performance are also presented in full cells, highlighting its potential for practical applications.

Steric Hindrance Engineering to Modulate the Closed Pores Formation of Polymer‐Derived Hard Carbon for High‐Performance Sodium‐Ion Batteries

AbstractThe closed pores play a critical role in improving the sodium storage capacity of hard carbon (HC) anode, however, their formation mechanism as well as the efficient modulation strategy at molecular level in the polymer‐derived HCs is still lacking. In this work, the steric hindrance effect has been proposed to create closed pores in the polymer‐derived HCs for the first time through grafting the aromatic rings within and between the main chains in the precursor. The experimental data and theoretical calculation demonstrate that steric‐hindrance effect from the aromatic ring side group can increase backbone rigidity and the internal free volumes in the polymer precursor, which can prevent the over graphitization and facilitate the formation of closed pores during the carbonization process. As a result, the as‐prepared HC anode exhibits a remarkably enhanced discharge capacity of 340.3 mAh/g at 0.1 C, improved rate performance (210.7 mAh/g at 5 C) as well as boosted cycling stability (86.4 % over 1000 cycles at 2 C). This work provides a new insight into the formation mechanisms of closed pores via steric hindrance engineering, which can shed light on the development of high‐performance polymer‐derived HC anode for sodium‐ion batteries.

Bimetallic Sulfide Sb2S3/FeS2 Heterostructure Anchored in a Carbon Skeleton for Fast and Stable Sodium Storage.

Sodium-ion batteries (SIBs) are a promising substitute for lithium batteries due to their abundant resources and low cost. Metal sulfides are regarded as highly attractive anode materials due to their superior mechanical stability and high theoretical specific capacity. Guided by the density functional theory (DFT) calculations, 3D porous network shaped Sb2S3/FeS2 composite materials with reduced graphene oxide (rGO) through a simple solvothermal and calcination method, which is predicted to facilitate favorable Na+ ion diffusion, is synthesized. Benefiting from the well-designed structure, the resulting Sb2S3/FeS2 exhibit a remarkable reversible capacity of 536 mAh g-1 after 2000 cycles at a current density of 5 A g-1 and long high-rate cycle life of 3000 cycles at a current density of 30 A g-1 as SIBs anode. In situ and ex situ analyses are carried out to gain further insights into the storage mechanisms and processes of sodium ions in Sb2S3/FeS2@rGO composites. The significantly enhanced sodium storage capacity is attributed to the unique structure and the heterogeneous interface between Sb2S3 and FeS2. This study illustrates that combining rGO with heterogeneous engineering can provide an ideal strategy for the synthesis of new hetero-structured anode materials with outstanding battery performance for SIBs.

Se-vacancy porous ultrathin ZnSe nanosheet/carbon composite for sodium storage via electron beam irradiation strategy

Zinc selenide (ZnSe) is a next-generation anode material due to its high sodium storage capacity. However, the poor conductivity and volume expansion lead to its capacity attenuation and short cycle life. Herein, Se-vacancy porous ultrathin ZnSe nanosheet/carbon composite (ZnSe@NC/N-GQD) is reported as a high-performance anode material for sodium-ion batteries. Organic-inorganic hybrid ZnSe(en)0.5 ultrathin nanosheets with abundant Se vacancies are rapidly prepared by electron beam irradiation for the first time. Using it as a precursor, Se-vacancy carbon-coated porous ultrathin ZnSe nanosheets loaded with nitrogen-doped graphene quantum dots (N-GQDs) are synthesized via carbonization and electrodeposition process. Through the design of ZnSe@NC/N-GQD, the sodium storage performance can be effectively improved by implementing nanostructure engineering (porous ultrathin nanosheet) via organic–inorganic hybrid, defect engineering (Se vacancy) via electron beam irradiation, and carbon composite (amorphous carbon and N-GQD). Consequently, ZnSe@NC/N-GQD delivers a high capacity of 483 mA h g−1 after 200 cycles at 0.5 A g−1, shows an outstanding rate capability of 381 mA h g−1 at 10.0 A g−1, and exhibits an excellent cycling stability of 86 % retention after 2800 cycles at 5.0 A g−1. This work develops a new method to rapidly prepare organic–inorganic nanohybrids, and proposes an innovative design of high-performance ZnSe-based anodes.

Commercial Carbon Fibers as Host for Sodium Deposition to Achieve High Volumetric Capacity

AbstractThe advancement of flexible electronic devices necessitates the utilization of electrode materials that offer robustness and high capacity. In this paper, it is revealed that commercially available carbon fibers with specific microcrystalline structures not only have high mechanical strength but also a high volumetric capacity of up to 300 mAh cm−3, surpassing conventional carbon materials. When multiple structural parameters of carbon fiber reach certain thresholds, a breakthrough in sodium storage capacity and rate performance can be achieved. This study further elucidates the mechanism whereby this specific carbon fiber primarily utilizes an all‐plateau sodium deposition mechanism, which occurs in pore‐like grain boundaries. Through in situ spectroscopy and synchrotron techniques, the reversible deposition process of metallic sodium has been revealed at different scales. Theoretical calculations and thermodynamic principles further confirm the desolvation and deposition mechanisms in carbon fibers. As a result, this research discovers the modulating effects and patterns of crystallinity, defect, and orientation of carbon materials on sodium storage sites and diffusion kinetics, thereby achieving controlled sodium storage. This work shows that commercial carbon fibers can serve as robust hosts for sodium deposition and enhances the theoretical understanding of how the microcrystalline structure of carbon materials relates to sodium storage properties.

Insight into the configuration of hard-soft carbon composites for high performance sodium-ion batteries

Hard carbon materials are considered suitable anode materials for sodium-ion batteries due to their abundant defect sites and large interlayer distance, which are respectively beneficial to the adsorption/desorption and insertion/extraction behaviors of Na+ during the electrochemical process. However, the poor electrical conductivity resulting from the intrinsic short-range ordered structure in the carbon skeleton and limited active sites significantly hinders their electrochemical performance. Herein, hard and soft carbon composites with various configurations are developed using a layer-by-layer coating method with SiO2 nanospheres as templates. These composites, including the hard carbon coated soft carbon composite structure (SC@HC), soft carbon coated hard carbon composite structure (HC@SC), and uniformly mixed soft and hard carbon composites (HSC), are prepared through confined-carbonization under the outermost SiO2 layer. The resulting hollow nanospheres possess ultra-small diameters (approximately 50 nm), ultra-thin wall thicknesses (5-6 nm), and different hard/soft carbon layer arrangements. Evaluation of sodium storage properties showed that the combination of soft and hard carbon outperformed pure soft or hard carbon, with HC@SC configuration offering materials with larger interlayer spacing, higher defect concentration, and a more complete conductive network. This enhances sodium storage capacity (293 mAh g-1@1 A g-1) and rate performance (242 mAh g-1@5 A g-1). The findings of this study present a novel approach to designing soft and hard carbon composites for high-performance sodium-ion batteries.