Antimony Nanoparticles Encapsulated in Self-Supported Organic Carbon with a Polymer Network for High-Performance Lithium-Ion Batteries Anode

Antimony (Sb) demonstrates ascendant reactive activation with lithium ions thanks to its distinctive puckered layer structure. Compared with graphite, Sb can reach a considerable theoretical specific capacity of 660 mAh g-1 by constituting Li3Sb safer reaction potential. Hereupon, with a self-supported organic carbon as a three-dimensional polymer network structure, Sb/carbon (3DPNS-Sb/C) composites were produced through a hydrothermal reaction channel followed by a heat disposal operation. The unique structure shows uniformitarian Sb nanoparticles wrapped in a self-supported organic carbon, alleviating the volume extension of innermost Sb alloying, and conducive to the integrality of the construction. When used as anodes for lithium-ion batteries (LIBs), 3DPNS-Sb/C exhibits a high invertible specific capacity of 511.5 mAh g-1 at a current density of 0.5 A g-1 after 100 cycles and a remarkable rate property of 289.5 mAh g-1 at a current density of 10 A g-1. As anodes, LIBs demonstrate exceptional electrochemical performance.

Impact of CO2 activation on the structure, composition, and performance of Sb/C nanohybrid lithium/sodium-ion battery anodes

Antimony (Sb) has been regarded as one of the most promising anode materials for both lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs) and attracted much attention in recent years. Alleviating the volumetric effect of Sb during charge and discharge processes is the key point to promote Sb-based anodes to practical applications. Carbon dioxide (CO2) activation is applied to improve the rate performance of the Sb/C nanohybrid anodes caused by the limited diffusion of Li/Na ions in excessive carbon components. Based on the reaction between CO2 and carbon, CO2 activation can not only reduce the excess carbon content of the Sb/C nanohybrid but also create abundant mesopores inside the carbon matrix, leading to enhanced rate performance. Additionally, CO2 activation is also a fast and facile method, which is perfectly suitable for the fabrication system we proposed. As a result, after CO2 activation, the average capacity of the Sb/C nanohybrid LIB anode is increased by about 18 times (from 9 mA h g-1 to 160 mA h g-1) at a current density of 3300 mA g-1. Moreover, the application of the CO2-activated Sb/C nanohybrid as a SIB anode is also demonstrated, showing good electrochemical performance.

Microsized Antimony as a Stable Anode in Fluoroethylene Carbonate Containing Electrolytes for Rechargeable Lithium-/Sodium-Ion Batteries

Metallic antimony (Sb) is an attractive anode material for lithium-/sodium-ion batteries (LIBs/SIBs) because of its high theoretical capacity (660 mA h g^-1), but it suffers from poor cycling performance caused by the huge volume expansion and the unstable solid electrolyte interphase (SEI). Here, we report a high-performing microsized Sb anode for both LIBs and SIBs by coupling it with fluoroethylene carbonate (FEC) containing electrolytes. The optimum amount of FEC (10 vol %) renders a stable LiF/NaF-rich SEI on Sb electrodes that can suppress the continuous electrolyte decomposition and accommodate the volume variation. The microsized Sb electrode gradually evolves into a porous integrity assembled by nanoparticles in FEC-containing electrolytes during cycling, which is totally different from that in the FEC-free counterpart. As a result, the microsized Sb electrodes exhibit a reversible capacity of 540 mA h g^-1 with 85.3% capacity retention after 150 cycles at 1000 mA g^-1 for LIBs and 605 mA h g^-1 with 95.4% capacity retention after 150 cycles at 200 mA g^-1 for SIBs. More impressively, the prototype full Li-based (i.e., Sb/LiNi_0.8Co_0.1Mn_0.1O₂ cell) and Na-based (i.e., Sb/Na₃V₂(PO₄)₂O₂F cell) batteries also achieve good cycling durability. This facile strategy of electrolyte formulation to boost the cycling performance of microsized Sb anodes will provide a new avenue for developing stable alloying-type materials for both LIBs and SIBs.

Sb2S3 Nanoparticles Anchored or Encapsulated by the Sulfur-Doped Carbon Sheet for High-Performance Supercapacitors

The specific capacitance and energy density of antimony trisulfide (Sb₂S₃)@carbon supercapacitors (SCs) have been limited and are in need of significant improvement. In this work, Sb₂S₃ nanoparticles were selectively encapsulated or anchored in a sulfur-doped carbon (S-carbon) sheet depending on the use of microwave-assisted synthesis. The microwave-triggered Sb₂S₃ nanoparticle growth resulted in core-shell hierarchical spherical particles of uniform diameter assembled with Sb₂S₃ as the core and an encapsulated S-carbon layer as the shell (Sb₂S₃-M@S-C). Without the microwave mediation, the other nanostructure was found to comprise fine Sb₂S₃ nanoparticles widely anchored in the S-carbon sheet (Sb₂S₃-P@S-C). Structural and morphological analyses confirmed the presence of encapsulated and anchored Sb₂S₃ nanoparticles in the carbon. These two materials exhibited higher specific capacitance values of 1179 (0 to +1.0 V) and 1380 F·g^-1 (-0.8 to 0 V) at a current density of 1 A·g^-1, respectively, than those previously reported for Sb₂S₃ nanomaterials in considerable SCs. Furthermore, both materials exhibited outstanding reversible capacitance and cycle stability when used as SC electrodes while retaining over 98% of the capacitance after 10 000 cycles, which indicates their long-term stability. Furthermore, a hybrid Sb₂S₃-M@S-C/Sb₂S₃-P@S-C device was designed, which delivers a remarkable energy density of 49 W·h·kg^-1 at a power density of 2.5 kW·kg^-1 with long-term cycle stability (94% over 10 000 cycles) and is comparable to SCs in the recent literature. Finally, a light-emitting diode (LED) panel comprising 32 LEDs was powered using three pencil-type hybrid SCs in series.

Environmentally Sustainable Aluminum-Coordinated Poly(tetrahydroxybenzoquinone) as a Promising Cathode for Sodium Ion Batteries

Na-ion batteries are attractive as an alternative to Li-ion batteries because of their lower cost. Organic compounds have been considered as promising electrode materials due to their environmental friendliness and molecular diversity. Herein, aluminum-coordinated poly(tetrahydroxybenzoquinone) (P(THBQ-Al)), one of the coordination polymers, is introduced for the first time as a promising cathode for Na-ion batteries. P(THBQ-Al) is synthesized through a facile coordination reaction between benzoquinonedihydroxydiolate (C₆O₆H₂^2-) and Al³⁺ as ligands and complex metal ions, respectively. Tetrahydroxybenzoquinone is environmentally sustainable, because it can be obtained from natural resources such as orange peels. Benzoquinonedihydroxydiolate also contributes to delivering high reversible capacity, because each benzoquinonedihydroxydiolate unit is capable of two electron reactions through the sodiation of its conjugated carbonyl groups. Electrochemically inactive Al³⁺ improves the structural stability of P(THBQ-Al) during cycling because of a lack of a change in its oxidation state. Moreover, P(THBQ-Al) is thermally stable and insoluble in nonaqueous electrolytes. These result in excellent electrochemical performance including a high reversible capacity of 113 mA h g^-1 and stable cycle performance with negligible capacity fading over 100 cycles. Moreover, the reaction mechanism of P(THBQ-Al) is clarified through ex situ XPS and IR analyses, in which the reversible sodiation of C═O into C-O-Na is observed.

Synergistic effect of cross-linked carbon nanosheet frameworks and Sb on the enhancement of sodium storage performances

Cross-linked carbon nanosheets (CCNFs) are employed to anchor Sb nanoparticles to improve the sodium storage performances, and the synergistic effect of cross-linked carbon nanosheet frameworks and Sb is investigated.

Ultralong Sb2Se3 Nanowire-Based Free-Standing Membrane Anode for Lithium/Sodium Ion Batteries

Metal chalcogenides have emerged as promising anode materials for lithium ion batteries (LIBs) and sodium ion batteries (SIBs). Herein, a free-standing membrane based on ultralong Sb₂Se₃ nanowires has been successfully fabricated via a facile hydrothermal synthesis combined with a subsequent vacuum filtration treatment. The as-achieved free-standing membrane constructed by pure Sb₂Se₃ nanowires exhibits good flexibility and integrity. Meanwhile, we investigate the lithium and sodium storage behavior of the Sb₂Se₃ nanowire-based free-standing membrane. When applied as the anode for LIBs, it delivers a reversible capacity of 614 mA h g^-1 at 100 mA g^-1, maintaining 584 mA h g^-1 after 50 cycles. When applied as the anode for SIBs, it delivers a reversible capacity of 360 mA h g^-1 at 100 mA g^-1, retaining 289 mA h g^-1 after 50 cycles. Such difference in electrochemical performance can be attributed to the more complex sodiation process relative to the corresponding lithiation process. This work may provide insight on developing Sb₂Se₃-based anode materials for high-performance LIBs or SIBs.

Double-Walled Sb@TiO2-x Nanotubes as a Superior High-Rate and Ultralong-Lifespan Anode Material for Na-Ion and Li-Ion Batteries

Double-walled Sb@TiO2- x nanotubes take full advantage of the high capacity of Sb, the good stability of TiO2- x , and their unique interaction, realizing excellent electrochemical performance both in lithium-ion batteries and sodium-ion batteries.

Na-Ion Battery Anodes: Materials and Electrochemistry

The intermittent nature of renewable energy sources, such as solar and wind, calls for sustainable electrical energy storage (EES) technologies for stationary applications. Li will be simply too rare for Li-ion batteries (LIBs) to be used for large-scale storage purposes. In contrast, Na-ion batteries (NIBs) are highly promising to meet the demand of grid-level storage because Na is truly earth abundant and ubiquitous around the globe. Furthermore, NIBs share a similar rocking-chair operation mechanism with LIBs, which potentially provides high reversibility and long cycling life. It would be most efficient to transfer knowledge learned on LIBs during the last three decades to the development of NIBs. Following this logic, rapid progress has been made in NIB cathode materials, where layered metal oxides and polyanionic compounds exhibit encouraging results. On the anode side, pure graphite as the standard anode for LIBs can only form NaC64 in NIBs if solvent co-intercalation does not occur due to the unfavorable thermodynamics. In fact, it was the utilization of a carbon anode in LIBs that enabled the commercial successes. Anodes of metal-ion batteries determine key characteristics, such as safety and cycling life; thus, it is indispensable to identify suitable anode materials for NIBs. In this Account, we review recent development on anode materials for NIBs. Due to the limited space, we will mainly discuss carbon-based and alloy-based anodes and highlight progress made in our groups in this field. We first present what is known about the failure mechanism of graphite anode in NIBs. We then go on to discuss studies on hard carbon anodes, alloy-type anodes, and organic anodes. Especially, the multiple functions of natural cellulose that is used as a low-cost carbon precursor for mass production and as a soft substrate for tin anodes are highlighted. The strategies of minimizing the surface area of carbon anodes for improving the first-cycle Coulombic efficiency are also outlined, where graphene oxide was employed as dehydration agent and 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) was used to unzip wood fiber. Furthermore, surface modification by atomic layer deposition technology is introduced, where we discover that a thin layer of Al2O3 can function to encapsulate Sn nanoparticles, leading to a much enhanced cycling performance. We also highlight recent work about the phosphorene/graphene anode, which outperformed other anodes in terms of capacity. The aromatic organic anode is also studied as anode with very high initial sodiation capacity. Furthermore, electrochemical intercalation of Na ions into reduced graphene oxide is applied for fabricating transparent conductors, demonstrating the great feasibility of Na ion intercalation for optical applications.

Facile synthesis of symmetric bundle-like Sb2S3 micron-structures and their application in lithium-ion battery anodes

A two-step oxidation–sulfuration route is developed to fabricate the bundle-like Sb₂S₃ micron-structure, in which hundreds of 1D nanowires are tied.

Ultrafine Sb nanoparticles embedded in an amorphous carbon matrix for high-performance sodium ion anode materials

SbNPs@C nanocomposite display a uniform “sea-island” structure with Sb nanoparticles' sizes ranging from 5 to 20 nm and exhibit superior electrochemical performances for SIBs anode materials.

Sb Nanoparticles Encapsulated in a Reticular Amorphous Carbon Network for Enhanced Sodium Storage

Sb nanoparticles encapsulated in 3D reticular carbon network (denoted Sb@3D RCN) film are prepared by the electrostatic spray deposition technique followed by a heat treatment. When used as a binder-free anode for a Na-ion battery, it shows excellent long-life cyclability. The unique reticular, porous, and core-shell structure of Sb@3D RCN contributes significantly to the excellent sodium storage performance.

High rate capability and superior cycle stability of a flower-like Sb2S3 anode for high-capacity sodium ion batteries

Flower-like antimony sulfide structures were prepared by a simple and easy polyol reflux process. When tested as an anode for sodium ion batteries, the material delivered a high reversible capacity of 835.3 mA h g(-1) at 50 mA g(-1) after 50 cycles and maintained a capacity of 641.7 mA h g(-1) at 200 mA g(-1) after 100 cycles. Even up to 2000 mA g(-1), a capacity of 553.1 mA h g(-1) was obtained, indicating an excellent cycle performance and a superior rate capability. The mechanism of the formation of the micro-flowers was also investigated. The additive used facilitates the controlled release of the reactant to form uniform, shaped nanosheets and an optimum reaction time allows the nanosheets to self-assemble into micro-flowers.

SnSe alloy as a promising anode material for Na-ion batteries

SnSe alloy is examined for the first time as an anode for Na-ion batteries, and shows excellent electrochemical performance.

In situ TEM study of the Li–Au reaction in an electrochemical liquid cell

We study the lithiation of a Au electrode in an electrochemical liquid cell using transmission electron microscopy (TEM). The commercial liquid electrolyte for lithium ion batteries (1 M lithium hexafluorophosphate LiPF₆ dissolved in 1 : 1 (v/v) ethylene carbonate (EC) and diethyl carbonate (DEC)) was used. Three distinct types of morphology change during the reaction, including gradual dissolution, explosive reaction and local expansion/shrinkage, are observed. It is expected that significant stress is generated from lattice expansion during lithium–gold alloy formation. There is vigorous bubble formation from electrolyte decomposition, likely due to the catalytic effect of Au, while the bubble generation is less severe with titanium electrodes. There is an increase of current in response to electron beam irradiation, and electron beam effects on the observed electrochemical reaction are discussed.