High-performance Anode For Sodium-ion Batteries Research Articles

Biphenylene monolayer: a novel nonbenzenoid carbon allotrope with potential application as an anode material for high-performance sodium-ion batteries.

Allotrope metal structures composed of carbon as anode materials for metal-ion batteries are a current research hotspot. In this work, the recently synthesized graphene allotrope, two-dimensional (2D) biphenylene, consisting of tetragonal, hexagonal and octagonal carbon rings, was explored theoretically. Our first-principles calculations verified that 2D biphenylene has dynamical, mechanical and thermal stability and exhibits metallic features. Its novel structure can provide multiple adsorption sites for Na ions, a fast charge-discharge rate (low Na migration barriers of <0.2 eV) and high theoretical capacity (1075.37 mA h g-1). These superior properties, combined with its carbon abundance and light mass, make the biphenylene monolayer a promising high-performance anode for sodium-ion batteries (SIBs).

Engineering monodispersed 2 nm Sb2S3 particles embedded in a porphyrin-based MOF-derived mesoporous carbon network via an adsorption method to construct a high-performance sodium-ion battery anode.

Sodium ion batteries (SIBs) are expected to replace lithium ion batteries (LIBs) as the next generation of large-scale energy storage applications because of their superior cost performance. However, the larger ionic radius of Na+ causes a remarkable volume expansion than that of Li+ during charge and discharge, which reduces the performance of the battery. In this work, we engineered a composite material in that monodispersed 2 nm Sb2S3 particles are uniformly loaded into a carbon matrix (Sb2S3/CZM), which is obtained by carbonization of a zirconium-based MOF with adsorption of Sb. The obtained composite material has a high specific surface area in favor of mass transfer, and the porous structure can resist many volume changes in the circulation process. Moreover, the ultrafine Sb2S3 particles are well-distributed in the composite material, which increases the utilization of the active substance and is promising for the storage of Na+. Based on its unique structure, the Sb2S3/CZM composite shows a specific capacity of 550 mA h g-1 at 100 mA g-1 and an excellent cycling stability of 88.9% retention after 1000 cycles at 3 A g-1. The excellent electrochemical performance provides enlightenment for the rational design of hierarchical heterostructures for energy storage applications.

Hierarchical soot nanoparticle self-assemblies for enhanced performance as sodium-ion battery anodes

Soot nanoparticles, that are considered as pollutants, have been utilized in the fabrication of a high-performance sodium-ion battery anode, which exhibits comparable electrochemical cycling as those prepared from commercial hard carbon materials.

An elemental sulfur/CoS2- ionic liquid based anode for high-performance aqueous sodium-ion batteries

Despite having advantages of safety and dominating consumer and electric vehicle market, the progress of aqueous rechargeable battery research is hindered by low capacity anode materials. A game-changing strategy is to use an environmentally benign aqueous electrolyte with earth abundance Na-ion and sulfur. Sulfur promises to be a next-generation electrode material due to its high theoretical capacity and energy density. But the practical application of elemental sulfur in aqueous electrolyte suffer from sharp capacity decay due to the dissolution of polysulfides. Herein, we report 70 % elemental sulfur along with CoS2 and 1‑butyl‑3-methylimidazolium o,o-bis(2-ethylhexyl) dithiophosphate (BMIm-DDTP) ionic liquid (IL) as anode (S@CoS2-IL) for aqueous rechargeable sodium-ion/sulfur batteries (ARSSB) in 2 M aq. Na2SO4 electrolyte.The S@CoS2-IL anode delivers an outstanding capacity of 977 mA h g−1 (> 91 % of the theoretical capacity of elemental sulfur i.e. 1070 mA h g−1), at 0.5 C with a stable cycling performance over 100 cycles with > 98 % of capacity retention at 2 C with 100 % of coulombic efficiency. A negligible loss of S was confirmed by UV–Vis spectroscopy and potentiometric titration and anchoring of polysulfide at S@CoS2-IL anode were evidenced by NMR, ESI-mass, Raman and X-ray photoelectron spectroscopy. The synergy between highly active CoS2 and BMIm-DDTP IL from the dynamic coordination of dithiophosphate with CoS2 provides easy access for polysulfides anchoring and fast reaction kinetics which effectively suppresses the dissolution of discharge polysulfides and HS−. The full cell studies using S@CoS2-IL anode with standard Na0.44MnO2 cathode demonstrate an outstanding capacity of 778 mA h g−1 w.r.t the weight of S and 104.98 mA h g−1 (of total electrodes weight), which is close to the theoretical capacity of 109 mA h g−1 with 100 % coulombic efficiency and 91.8 % capacity retention over 400 cycles at 2 C. The excellent performance of this aqueous battery chemistry shows that S@CoS2-IL anode has great potential towards practical application in ARSSB.

Boosting the High Capacitance-Controlled Capacity of Hard Carbon by Using Surface Oxygen Functional Groups for Fast and Stable Sodium Storage

Heteroatom doping is identified as an effective strategy to enhance the electrochemical performance of hard carbon. However, the effect of oxygen on biomass-based hard carbon is usually ignored. Herein, oxygen-doped carbon microspheres are fabricated with a lignin-based oxygen source, endowing the carbon microspheres with a high capacitance-controlled capacity and stable cycling performance. In addition, the quality of oxygen doping and microsphere morphology is regulated by using different ratios of lignin. As an anode for sodium-ion batteries, the optimal oxygen-doped carbon microspheres can deliver a high reversible capacity (310.4 mAh g–1 at 25 mA g–1) and long life span. Moreover, when paired with NaNi1/3Fe1/3Mn1/3O2, the full cells can display a capacity of 313.3 mAh g–1 at 25 mA g–1 and an excellent rate performance (218.7 mAh g–1 at 500 mA g–1). Based on first principles, the oxygen functional groups provided by lignin exhibit a strong Na+ adsorption capability, demonstrating that oxygen functional groups, especially C═O, play a pivotal role in the capacitance-controlled process. This work presents an idea for the material design and heteroatom doping of high-performance sodium-ion battery anode materials.

3D porous Fluorine-Doped NaTi2(PO4)3@C as High-Performance Sodium-Ion battery anode with broad temperature adaptability

Sodium-ion batteries (SIBs) are an appealing alternative to lithium-ion batteries in large-scale energy storage systems owing to their low cost and the abundance of sodium resources. As promising anode materials for SIBs, NASICON type NaTi2(PO4)3 material with robust structure possesses high ionic mobility, whereas its intrinsic low electronic conductivity degrades the performance of SIBs severely. Herein, we propose a strategy of fluorine-doped NaTi2(PO4)3@C (F-NTP@C) with three-dimensional (3D) porous structure to boost Na+ storage capability. When applied to SIBs half cells, it delivers a reversible capacity of 108.7 mA h g−1 at 50C and a capacity retention of 75.5% after 2000 cycles at 10C, as well as showing broad temperature adaptability from 0 to 50 °C. In-situ XRD is also conducted to gain an insight into Na+ storage mechanism. By coupling the experiment data with theoretical calculation, it is concluded that the enhanced electronic conductivity and fast Na+ kinetics are attributed to the incorporation of F- ions and the design of 3D porous structure. Additionally, sodium ion full cells composed of F-NTP@C anode and Na3V2(PO4)2F3@C cathode exhibit durable and practical sodium storage performance in wide temperature range (0 ∼ 50 °C), which provides a feasibility for the large-scale production of high performance SIBs.

Dispersed Cu2S/Ni3S2 nanoparticles encased in carbon layers as high-performance anodes for sodium-ion batteries

Owing to high theoretical capacity, nickel sulfides are competitive anode materials for sodium-ion batteries (SIBs). Nevertheless, their developments are greatly obstructed by low conductivity, as well as poor cycle stability resulted from structural pulverization and collapse. Herein, dispersed Ni 3 S 2 nanoparticles (20–30 nm) are encased in carbon shells (NiS x @C) through a simple hydrothermal reaction and carbon coating process. The dispersed nanoparticles provide short ion transport channels and a large number of active sites for sodium storage, and carbon coating can enhance the conductivity and structural stability of materials. Meanwhile a small amount of copper is added to further increase the capacity of materials based on synergistic effect and increase of defects. The Cu 2 S/NiS x @C composite electrode exhibits an outstanding pseudocapacitive behavior in reaction kinetics. Evaluated as an anode for SIBs, such electrode performs a high rate capability of 343.8 mAh g −1 at 5 A g −1 and excellent cycling performance of 485.3 mAh g −1 at 0.1 A g −1 after 100 cycles and 350.4 mAh g −1 at 0.5 A g −1 after 500 cycles. This work shows that nickel sulfides are promising materials for sodium-ion storage through structural design and modification, and would be of great significance to promote the development of advanced SIBs. • The Cu 2 S/NiS x @C composite were prepared by hydrothermal and carbon coating process. • A jujube cake-like structure with nanoparticles dispersed in sealed carbon shells. • Exhibiting an outstanding pseudocapacitive property in reaction kinetics. • Delivering a capacity of 350.4 mAh g −1 (84.6%) at 0.5 A g −1 after 500 cycles. • Having excellent comprehensive performance.

Construction of N-doped C@MoS2 heteroshell with the yolk of Sn nanoparticles as high-performance anodes for sodium-ion batteries

Herein, we demonstrate the reasonable design and preparation of yolk-heteroshell Sn@N-doped C@MoS2 nanospheres as anode materials in sodium-ion battery. Through an effective multi-step strategy, Sn nanoparticles are encapsulated in N-doped C nanocage surrounded by ultra-thin MoS2 nanosheets to form Sn@N-doped C@MoS2 nanospheres. In this novel structure, Sn nanoparticles with high theoretical capacity improve the space utilization inside the heteroshell; the N-doped carbon nanocage as the skeleton not only inhibits the mutual accumulation of Sn and MoS2, but also improves conductivity; the outer MoS2 ultra-thin sheets can consolidate C@MoS2 heteroshell, provide numerous active sites and favor the fast diffusion of Na+/e-. Notably, the combination of carbon nanocage and MoS2 sheets in the yolk-heteroshell structure can effectually buffer the volume expansion of Sn nanoyolks and reinforce C@MoS2 heteroshell while reducing the carbon content. Therefore, the yolk-heteroshell structure plays a crucial role in enhanced reversible capacity and cyclic stability of Sn@N-doped C@MoS2 nanospheres, which activates their sodium storage potential. The yolk-heteroshell Sn@N-doped C@MoS2 nanospheres exhibit high reversible capacity of 488.4 mAh g−1 at 0.1 A g−1 after 300 cycles and long-cycle stability of 350.6 mAh g−1 at 0.5 A g−1 after 500 cycles. Moreover, their full cell delivers a stable reversible discharge capacity of about 80.1 mAh g−1 after 30 cycles at 0.5 C. This work provides a feasible yolk-heteroshell strategy for Sn-based composite nanomaterials.

Flexible Sb/Sb2O3-C nanofibers as binder-free anodes for high-performance and stable sodium-ion batteries

Antimony-based electrode materials with conventional slurry-casting process still face great challenges such as tedious preparation process and unsatisfying cycling stability for sodium ion batteries (SIBs). Therefore, the design and fabrication of integrated electrodes with binder-free and even current collector-free are highly significant. Herein, we fabricated flexible Sb/Sb2O3-C nanofibers (NFs) films utilizing a facile combination of electrospinning technique and carbonization. Sb/Sb2O3 nanoparticles are well embedded in carbon NFs with a fiber diameter of ca. 340 nm. The fabricated NFs films can be directly used as binder and current collector-free anodes for SIBs and exhibited high-capacity and long-lifetime cycles (385.6 mAh g−1 over 500 cycles). Ex situ SEM and TEM observations re-appear their intact fibrous network morphology and stable one-dimensional composite structures after hundreds of discharging-charging cycles, demonstrating that Sb/Sb2O3-C NFs film is a promising binder-free electrode for SIBs.

Flexible SnTe/carbon nanofiber membrane as a free-standing anode for high-performance lithium-ion and sodium-ion batteries

Flexible electrode plays a key role in flexible energy storage devices. The SnTe/C nanofibers membrane (SnTe/CNFM) with excellent mechanical flexibility has been successfully synthesized for the first time through electrospinning, and it demonstrates outstanding electrochemical performance as free-standing anode for lithium/sodium-ion batteries. The SnTe/CNFM electrode delivers a discharge capacity of 526.7 mAh g−1 at 1000 mA g−1 after 1000 cycles in lithium-ion half-cells and a discharge capacity of 236.5 mAh g−1 at 500 mA g−1 after 80 cycles in lithium-ion full-cells with a LiFePO4 cathode. Not only that, it shows a discharge capacity of 182.7 mAh g−1 at 200 mA g−1 after 200 cycles in sodium-ion half-cells and a high discharge capacity of 207.0 mAh g−1 at 500 mA g−1 after 50 cycles in sodium-ion full-cells with a Na0.44MnO2 cathode. Moreover, the prepared SnTe/CNFM exhibits good mechanical flexibility. The SnTe/CNFM can still return to its original state without any breakage after bending, curling, folding and kneading. These results indicate that SnTe/CNFM is expected to become one of the promising free-standing anodes for lithium/sodium-ion batteries.

SbPS4: A novel anode for high-performance sodium-ion batteries

With the in-depth research of sodium-ion batteries (SIBs), the development of novel sodium-ion anode material has become a top priority. In this work, tube cluster-shaped SbPS4 was synthesized by a high-temperature solid phase reaction. Then the typical short tubular ternary thiophosphate SbPS4 compounded with graphene oxide (SbPS4/GO) was successfully synthesized after ultrasonication and freeze-drying. SbPS4 shows a high theoretical specific capacity (1335 mAh/g) according to the conversion-alloying dual mechanisms. The unique short tube inserted in the spongy graphene structure of SbPS4/GO results in boosting the Na ions transport and alleviating the huge volume change in the charging and discharging processes, improving the sodium storage performance. Consequently, the tubular SbPS4 compounded with 10% GO provides an outstanding capacity of 359.58 mAh/g at 500 mA/g. The result indicates that SbPS4/GO anode has a promising application potential for SIBs.

Sn4P3-inlaid graphene oxide nanohybrid through low-temperature solid state reactions toward high-performance anode for sodium-ion batteries

Due to nature abundant and low-cost of sodium reserves with broad distribution in the earth's crust, sodium-ion batteries (SIBs) have attracted widespread attention for their great potential application in low-speed electric vehicles and large-scale energy storage system. However, their practical application is still hampered by the lack of decent anode materials. In this work, we develop an effective strategy to fabricate a nanohybrid of Sn4P3 and graphene oxide and demonstrate its outstanding sodium-storage behavior as an anode material for SIBs. By directly grinding tin(IV) chloride pentahydrate, sodium hydroxide, graphene oxide (GO) and surfactant PEG-200 at ambient temperature, an effective solid state reaction occurred to give rise to a precursor (named as SnO2/GO-PEG200), i.e. a nanocomposite of SnO2 encapsulated within GO matrix. After subsequent phosphorization at 280 °C using sodium hypophosphite monohydrate as phosphorous source, a nanohybrid of Sn4P3 and graphene oxide (designated as Sn4P3/GO-PEG200) was acquired. The coexistence of Sn4P3 nanoparticles and GO nanosheets endows the nanohybrid with improved electronic conductivity, highly structural integrity and superior electrochemical performance. When employed as anode material for SIBs, the nanohybrid anode demonstrates a good cycling stability (419 mA h g−1 after 100 cycles at 0.1 A g−1), with a remarkable rate capabilities (325 mA h g−1 at a current density of 1 A g−1 and 187 mA h g−1 at a current density of 5 A g−1, respectively).

Mesoporous cubic SnO2-CoO nanoparticles deposited on graphene as anode materials for sodium ion batteries

Insufficient lithium resource reserves will severely limit the development prospects of lithium-ion batteries. As the next generation of secondary batteries, sodium-ion batteries have attracted widespread attention. In recent years, people have used synergistic bimetal oxides instead of single metal oxides as anode materials for sodium ion batteries, but its electrochemical performance is still not ideal. Therefore, we synthesized cubic SnO2-Co3O4 hybrids by oxidizing CoSn(OH)6 precursor, and then prepared SnO2-CoO@Gr composites by a simple hydrothermal method. The SnO2-CoO@Gr-2 composite material with the graphene content of 9.6% as an anode material for sodium-ion batteries shows an initial discharge capacity of 598.9 mAh g−1 at a current density of 0.1 A g−1, and still has a reversible capacity of 302.8 mAh g−1 after 200 cycles. The introduction of graphene not only greatly restrains volume expansion of material during the cycle, but also effectively improves the conductivity of the composite material, which provides a great direction for preparing high-performance sodium ion battery anode materials.

Hierarchically Designed Nitrogen-Doped MoS2/Silicon Oxycarbide Nanoscale Heterostructure as High-Performance Sodium-Ion Battery Anode.

Molybedenum disulfide (MoS2) is regarded as a promising anode material for next-generation sodium-ion batteries (SIBs) owing to its high theoretical capacity. However, its low conductivity, large volume changes, and undesirable phase transformation hinder its practical applications. In this study, we synthesize a hierarchically designed core-shell heterostructure based on nitrogen-doped MoS2/C and silicon oxycarbide (SiOC) (N-MoS2/C@SiOC) via the facile pyrolysis of a suspension of an N-MoS2/polyfurfural precursor in silicone oil. The in situ nitrogen doping in a two-dimensional MoS2 structure with carbon incorporation leads to the enlargement of the interlayer spacing and enhancement of the electronic conductivity and mechanical stability, which allows the facile, highly reversible insertion and extraction of sodium ions upon cycling. Further, the nanoscale SiOC shell with surface capacitive reactivity provides a conductive pathway, preventing unfavorable side reactions at the electrode/electrolyte interface and acting as a structure-reinforcing buffer against severe volume expansion issues. As a result, the N-MoS2/C@SiOC composite exhibits high reversible capacity (540.7 mAh g-1), high-capacity retention (>100% after 200 cycles), and excellent rate capability up to 10 A g-1. The simple hierarchical core-shell design strategy developed in this study allows for the fabrication of high-performance metal sulfide anodes as well as other high-capacity anode materials for energy storage applications.

Three-dimensional Tremella-like FeS/C structure under pseudocapacitance as anode for high-performance sodium-ion batteries

In this work, a simple experimental method one-step hydrothermal method is made to prepare tremella-like FeS anchored into three-dimensional carbon (FeS/C) and get substantial progress in electrochemical properties and microstructure. The unique tremella-like structure is formed by the self-assembly of layered FeS/C, which would make the contact between the active material and the electrolyte sufficient, and maintain pronounced electrochemical performance. The studies show that the FeS/C synthesized is mainly dominated by the pseudocapacitive behavior in the electrochemical reaction processes, leading to fast the electrode reaction kinetics. The FeS/C anode also exhibits a large initial capacity of 619 mAh g−1 and remains 410.5 mAh g−1 with excellent rate performances.

FeS under wrinkled thin-layer carbon derived from ionic liquid as a high-performance sodium-ion battery anode material

FeS is a promising anode material with high theoretical capacity in sodium-ion batteries (SIBs). Unfortunately, the unstable structure and poor conductivity of FeS limit its commercial applications. Herein, FeS coated by wrinkled thin layers of carbon (FeS/C) is synthesized by using a simple pyrolysis strategy. The wrinkled carbon layers, which derived from ionic liquids, effectively improve the conductivity and structural stability of FeS. When employed as anode in SIBs, FeS/C exhibits high capacity, long cycle life, and excellent stability. Specifically, when the current density is 0.1 A g −1 and 0.5 A g −1 , the reversible capacity of FeS/C reaches 404.7 mAh g −1 and 304.8 mAh g −1 after 100 cycles. When the current density increases to 4 A g −1 , the sodium storage can maintain a capacity of 178.8 mAh g −1 after 1000 cycles. The excellent electrochemical performance can be attributed to the wrinkled carbon layers that enhance the structural stability and charge mobility.

Porous CuO/Cu2O heterostructured arrays as anode for high-performance sodium-ion batteries

Herein, CuO/Cu2O heterostructured arrays were successfully realized by in situ sculpturing Cu foam based on the hydrothermal protocol. Owing to the state-of-the-art design, CuO/Cu2O nanosheet arrays are tightly and intimately grown on Cu substrate. The abundant holes formed by the unique three-dimensional construction of Cu foam and the porous CuO/Cu2O nanosheets are significantly beneficial to the infiltration of electrolyte and enhancement of the Na+ diffusion efficiency. It is noted that CuO/Cu2O electrode shows superior areal capacity than that of the individual CuO and Cu2O electrodes. At the current density of 0.6 mA cm−2, there is a reversible capacity of 1.0 mAh cm−2 (322.6 mAh g−1) for the CuO/Cu2O anode. Even at 2.0 mA cm−2, a reversible capacity of 0.56 mAh cm−2 (180.6 mAh g−1) can be still obtained. The full sodium-ion battery demonstrates a high reversible capacity of 0.53 mAh cm−2 (170.9 mAh g−1) in the initial cycle at 0.5 mA cm−2.

Green large-scale production of N/O-dual doping hard carbon derived from bagasse as high-performance anodes for sodium-ion batteries

Sodium-ion batteries are considered as a promising candidate for lithium-ion batteries due to abundant sodium resources and similar intercalation chemistry. Hard carbon derived from biomass with the virtue of abundance and renewability is a cost-effective anode material. Herein, hard carbon is derived from renewable bagasse through a simple two-step method combining mechanical ball milling with carbonization. The hard carbon electrodes exhibit superior electrochemical performance with a high reversible capacity of 315 mA-h/g. Furthermore, the initial capacity of the full cell, HC//NaMn0.4Ni0.4Ti0.1Mg0.1O2, is 253 mA·h/g and its capacity retention rate is 77% after 80 cycles, which further verifies its practical application. The simple and low-cost preparation process, as well as excellent electrochemical properties, demonstrates that hard carbon derived from bagasse is a promising anode for sodium-ion batteries.

Highly stable Na metal anode enabled by a multifunctional hard carbon skeleton

Sodium (Na) metal and hard carbon are regarded as promising and competitive alternatives as anode materials for sodium-ion batteries (SIBs). Constructing a Na metal/hard carbon composite anode to exert a synergistic effect on the electrochemical performance of SIBs is highly desirable but rarely reported. In this work, we report a Na metal/N-functionalized hard carbon (NHC) composite as a high-performance anode for SIBs. The introduction of the N-functionalized groups transforms the surface chemistry of the hard carbon from sodiophobic to sodiophilic, thus significantly promoting the dispersion of the hard carbon in Na metal and facilitating the formation of an intimate interfacial contact between them. In addition, during Na stripping/plating cycling, the sodiated NHC particles homogenize the local electron distribution, while the desodiated NHC particles function as an artificial SEI film, which facilitate the bottom-up deposition of Na due to electron concentration gradient and mechanically inhibit the growth of Na dendrites. Consequently, the Na–NHC anode in the symmetric cell exhibits excellent cycling stability up to 1700 h without a short circuit, which significantly exceeds that of the bare Na anode. In the full cell with the Na–NHC anode, NaTi2(PO4)3 exhibits a significantly extended cycling life.

Nitrogen, Sulfur, and Phosphorus Codoped Hollow Carbon Microtubes Derived from Silver Willow Blossoms as a High-Performance Anode for Sodium-Ion Batteries

Hard carbon materials have been considered as one of the most promising candidates as the anode in sodium-ion batteries. However, scale application of state-of-the-art hard carbon anodes is still hampered on account of their complicated, toxic, and time-consuming preparation techniques. In the present paper, silver willow blossoms composed of natural micrometer-scale fibers are employed to construct N, S, and P codoped hollow carbon microtubes (HCMTs) by direct high-temperature carbonization. The HCMT has a nanoscale wall with several micrometer-sized hollow cavities, which is facilitated to optimize the sodium-ion transfer. In addition, the temperature-dependent, tailorable interlayer spacing coupled with doped heteroatoms is able to provide sufficient energy storage sites. By combining these unique structural advantages, the HCMT exhibits impressive sodium storage performance. The HCMT sample pyrolyzed under 1300 °C is able to deliver a highly reversible capacity of 302 mAh g–1, and after repeated charge/discharge for 100 times, the capacity retains 301 mAh g–1, indicating no visible degradation. Moreover, under a large current density up to 1 A g–1, a high capacity of 201 mAh g–1 is still achieved, demonstrating good rate capability.