RESUMEN
A zincophilic PAN@Zn(OTF)2 (PZO) separator with an extremely thin thickness of 65.6 µm is introduced. This separator with a low cost of 6.1 $ m-2, exhibiting excellent mechanical and wettability properties. The cell with the PZO separator exhibits impressive electrochemical performances both in symmetrical Zn||Zn cell and Zn||NVO full cell.
RESUMEN
Dual-ion battery (DIB) is an up-and-coming technology for the energy storage field. However, most of the current cathodes are still focused on the graphite hosts, which deliver a limited specific capacity. In this work, we demonstrated for the first time that H2PO4- can be used as the charge carrier for Na3V2(PO4)3 under an aqueous electrolyte, which enabled the V3+/V4+ and V4+/V5+ multielectron reactions in the Na3V2(PO4)3 electrode. The fabricated aqueous DIB delivers a high average voltage of â¼0.75 V (vs Ag/AgCl) and a high capacity of 280.7 mA h g-1. Moreover, the formed V5+-based novel cathode exhibits a capacity of 170.2 mA h g-1 in an organic sodium-ion battery. This study may open a new direction for fabricating high-voltage electrodes through the design of DIBs.
RESUMEN
Sodium-ion batteries (SIBs) as the next generation of sustainable energy technologies have received widespread investigations for large-scale energy storage systems (EESs) and smart grids due to the huge natural abundance and low cost of sodium. Although the great efforts are made in exploring layered transition metal oxide cathode for SIBs, their performances have reached the bottleneck for further practical application. Nowadays, anionic redox in layered transition metal oxides has emerged as a new paradigm to increase the energy density of rechargeable batteries. Based on this point, in this review, the development history of anionic redox reaction is attempted to systematically summarize and provide an in-depth discussion on the anionic redox mechanism. Particularly, the major challenges of anionic redox and the corresponding available strategies toward triggering and stabilizing anionic redox are proposed. Subsequently, several types of sodium layered oxide cathodes are classified and comparatively discussed according to Na-rich or Na-deficient materials. A large amount of progressive characterization techniques of anionic oxygen redox is also summarized. Finally, an overview of the existing prospective and the future development directions of sodium layered transition oxide with anionic redox reaction are analyzed and suggested.
RESUMEN
Rechargeable aqueous zinc batteries (AZBs) are one of the promising options for large-scale electrical energy storage owing to their safety, affordability and environmental friendliness. During the past decade, there have been remarkable advancements in the AZBs technology, which are achieved through intensive efforts not only in the area of electrode materials but also in the fundamental understandings of non-electrode components such as electrolytes, solid electrolyte interphase (SEI), current collectors, binders, and separators. In particular, the breakthroughs in the non-electrode components should not be underestimated in having enabled the AZBs to attain a higher energy and power density beyond that of the conventional AZBs, proving their critical role. In this article, the recent research progress is comprehensively reviewed with respect to non-electrode components in AZBs, covering the new-type of electrolytes that have been introduced, attempts for the tailoring of SEI, and the design efforts for multi-functional current collectors, binders and separators, along with the remaining challenges associated with these non-electrode components. Finally, perspectives are discussed toward future research directions in this field. This extensive overview on the non-electrode components is expected to guide and spur further development of high-performance AZBs.
RESUMEN
The sodium storage performance of a hard carbon (HC) anode in ether electrolytes exhibits a higher initial Coulombic efficiency (ICE) and better rate performance compared to conventional ester electrolytes. However, the mechanism behind faster Na storage kinetics for HC in ether electrolytes remains unclear. Herein, a unique solvated Na+ and Na+ co-intercalation mechanism in ether electrolytes is reported using designed monodispersed HC nanospheres. In addition, a thin solid electrolyte interphase film with a high inorganic proportion formed in an ether electrolyte is visualized by cryo transmission electron microscopy and depth-profiling X-ray photoelectron spectroscopy, which facilitates Na+ transportation, and results in a high ICE. Furthermore, the fast solvated Na+ diffusion kinetics in ether electrolytes are also revealed via molecular dynamics simulation. Owing to the contribution of the ether electrolytes, an excellent rate performance (214 mAh g-1 at 10 A g-1 with an ultrahigh plateau capacity of 120 mAh g-1 ) and a high ICE (84.93% at 1 A g-1 ) are observed in a half cell; in a full cell, an attractive specific capacity of 110.3 mAh g-1 is achieved after 1000 cycles at 1 A g-1 .
RESUMEN
All-solid-state sodium ion batteries (ASIBs) possess enhanced safety and desired cycling life compared with conventional liquid sodium batteries, showing great potential in large-scale energy storage systems. Polymer electrolytes based on poly(ethylene oxide) (PEO) have been extensively studied for ASIBs due to superior flexibility and processability. However, PEO-based electrolyte without any modification can hardly meet the requirements of ASIBs at room temperature. In the past decade, unremitting efforts have been attached to inhibiting crystallization of PEO, especially via ionic liquid plasticizing. However, the plasticizing mechanism is not clear. Here we incorporated Pyr13FSI into PEO-NaClO4 electrolyte to investigate the plasticizing effect by infrared spectrum characterizations and DFT calculations. The results indicate that FSI- anions tend to adhere to the PEO backbone, generating enhanced coordination ability and more coordination sites. Solid-state sodium ion batteries using PEO-NaClO4-40 wt % Pyr13FSI as polymer electrolyte exhibit good cycling and rate performance. Insights into the plasticizing mechanism contribute to fabricating polymer electrolyte with high performance for ASIBs.
RESUMEN
Sodium-ion batteries (SIBs) have attracted wide attention because of their prospects for grid-scale electrical regulation and cost effectiveness of sodium. In this regard, iron oxides (FeOx) are considered as one of the most promising anode candidates due to their high theoretical capacity and low cost. Unfortunately, the utilization of FeOx anodes suffers from sluggish reaction kinetics and significant lattice variation, causing insufficient rate performance and fast capacity degradation during the sodiation/desodiation process. In this study, Mn ions are incorporated through interstitial sites into a Fe3O4 lattice to form the Mn-incorporated Fe3O4/graphene (M-Fe3O4/G) composites through a facile hydrothermal method. Confirmed by XRD Rietveld refinement and the first-principles calculation, Mn occupation into the body structure can effectively condense the electron density around the Fermi level and thus contributes to the increased electrical conductivity and improved electrochemical properties. Accordingly, the M0.1Fe2.9O4/G composite demonstrates a high reversible capacity of 439.8 mA h g-1 at a current density of 100 mA g-1 over 200 cycles. Even at a high current density of 1 A g-1, the M-Fe3O4/G composites remain stable for over 1200 cycles, delivering a capacity of 210 mA h g-1. Coupled with a Na3V2(PO4)3-type cathode, the Mn-incorporated Fe3O4/G composites demonstrate good suitability in full SIBs (161.2 mA h g-1 at the current density of 1 A g-1 after 100 cycles). The regulation of Mn ions in the Fe3O4 lattice provides insights into the optimization of metal oxide anode candidates for their application in SIBs.
RESUMEN
Two-dimensional energy materials have been widely applied in advanced secondary batteries, among which molybdenum sulfide (MoS2) is attractive because of the potential for high capacity and good rate performance. The relatively low electronic conductivity and irreversible volume expansion of pure MoS2 still need to be improved. Here, a facile and highly efficient ex situ electrospinning technique is developed to design the carbon nanofiber elastically confined MoS2 nanoflowers flexible electrode. The flexible freestanding electrode exhibits enhanced electronic conductivities and ionic diffusion coefficients, leading to a remarkable high specific capacity (596 mA h g-1 at a current density of 50 mA g-1) and capacity retention (with 89% capacity retention after 1100 cycles at 1 A g-1). This novel idea underscores the potential importance of fabricating various flexible devices other than the sodium-ion battery.
RESUMEN
Sodium alginate (SA) is investigated as the aqueous binder to fabricate high-performance, low-cost, environmentally friendly, and durable TiO2 anodes in sodium-ion batteries (SIBs) for the first time. Compared to the conventional polyvinylidene difluoride (PVDF) binder, electrodes using SA as the binder exhibit significant promotion of electrochemical performances. The initial Coulombic efficiency is as high as 62% at 0.1 C. A remarkable capacity of 180 mAh g-1 is achieved with no decay after 500 cycles at 1 C. Even at 10 C (3.4 A g-1), it remains 82 mAh g-1 after 3600 cycles with approximate 100% Coulombic efficiency. TiO2 electrodes with SA binder display less electrolyte decomposition, fewer side reactions, high electrochemistry reaction activity, effective suppression of polarization, and good electrode morphology, which is ascribed to the rich carboxylic groups, high Young's modulus, and good electrochemical stability of SA binder.
RESUMEN
The development of portable and wearable electronics has aroused the increasing demand for flexible energy-storage devices, especially for the characteristics of high energy density, excellent mechanical properties, simple synthesis process, and low cost. However, the development of flexible electrodes for sodium-ion batteries (SIBs) is still limited due to the intricate production methods and the relatively high-cost of current collectors such as graphene/graphene oxide and carbon nanotubes. Here, the hierarchical 3D electronic channels wrapped large-sized Na3 V2 (PO4 )3 is designed and fabricated by a simple electrospinning technique. As flexible electrode material, it exhibits outstanding electrolyte wettability, together with ultrafast electronic conductivity and high Na-ion diffusion coefficients for SIBs, leading to superior electrochemical performances. A high reversible specific capacity of 116 mA h g-1 (nearly 99% of the theoretical specific capacities) can be obtained at the current density of 0.1 C. Even after a 300-fold current density increased (30 C), the discharge specific capacity of the flexible electrode still remains 63 mA h g-1 . Such an effective concept of fabricating 3D electronic channels for large-sized particles is expected to accelerate the practical applications of flexible batteries at various systems.
RESUMEN
To understand the slow capacity activation behavior of anatase TiO2 as a sodium-ion battery anode during cycling, a nanoporous configuration was designed and prepared. On the basis of the comprehension of the Na-ion storage mechanism, the behavior is demonstrated to be related with the gradual formation of amorphous phase resulting from the phase transition during discharge. In addition, the level of phase transition is determined by the discharge rates and cycle numbers, which strongly affects the electrochemical performance of anatase TiO2. Via a quick formation process of the amorphous phase in the initial cycles, the capacity activation is accelerated, and high initial capacity is achieved with no fading after 500 cycles. Particularly, anatase TiO2 displays surprisingly unique properties in the fast charge (even at 20 C, 6.7 A g-1) mode, delivering a 179 mA h g-1 charge capacity. This study is significant for the comprehensive understanding of the controversial sodium storage mechanisms and unclear special behaviors occurring in anatase TiO2, thus greatly contributing to better guidance on the computational studies and experiment technologies for further performance promotion.
RESUMEN
Sodium-ion batteries, representative members of the post-lithium-battery club, are very attractive and promising for large-scale energy storage applications. The increasing technological improvements in sodium-ion batteries (Na-ion batteries) are being driven by the demand for Na-based electrode materials that are resource-abundant, cost-effective, and long lasting. Polyanion-type compounds are among the most promising electrode materials for Na-ion batteries due to their stability, safety, and suitable operating voltages. The most representative polyanion-type electrode materials are Na3V2(PO4)3 and NaTi2(PO4)3 for Na-based cathode and anode materials, respectively. Both show superior electrochemical properties and attractive prospects in terms of their development and application in Na-ion batteries. Carbonophosphate Na3MnCO3PO4 and amorphous FePO4 have also recently emerged and are contributing to further developing the research scope of polyanion-type Na-ion batteries. However, the typical low conductivity and relatively low capacity performance of such materials still restrict their development. This paper presents a brief review of the research progress of polyanion-type electrode materials for Na-ion batteries, summarizing recent accomplishments, highlighting emerging strategies, and discussing the remaining challenges of such systems.
RESUMEN
Pursuing for novel electrode materials is significant for the progress of sodium ion batteries (SIBs). Here, a multilayered electride prepared by simple thermal decomposition of solid Ca3N2, namely Ca2N, is introduced as a new anode material of SIBs for the first time, and a compression molding electrode fabricated by pressing Ca2N powder into nickel foam is applied to protect Ca2N from trace moisture and oxygen. The as-prepared electrode delivers an initial discharge capacity of 1110.5 mAh g-1 and a reversible discharge capacity of â¼320 mAh g-1. These results suggest that Ca2N has a great potential for sodium ion batteries.
RESUMEN
In order to get an element substituted into Na3V2(PO4)3/C in an appointed V site, the simple sol-gel method is used to design and prepare a series of Na-rich Na3+xV2-xNix(PO4)3/C (x = 0-0.07) compounds. To get a charge balance, the ratio of Na, V, and Ni would be changed if Ni goes into a different site. Hence, ICP is applied to probe the real stoichiometry of the as-prepared Na3+xV2-xNix(PO4)3/C (x = 0-0.07). According to the Na/V ratio from the ICP result, it indicates that Ni2+ goes to a V site, and more Na+ will be introduced into the crystal to keep the charge balance. In addition, the crystal structure changes are explored by XRD and Rietveld refinement, it is indicated from the results that Ni2+ doping does not destroy the lattice structure of Na3V2(PO4)3. When applied as Na-storage material, the electrochemical property of all Ni2+ doped Na3+xV2-xNix(PO4)3/C composites have been significantly improved, especially for the Na3.03V1.97Ni0.03(PO4)3/C sample. For example, 107.1 mAh g-1 can be obtained at the first cycle; after 100 cycles, the capacity retention is as high as 95.5%. Moreover, when charging/discharging at a higher rate of 5 C, the capacity still remains 88.9 mAh g-1, displaying good rate performance. The good electrochemical performance is ascribed to the optimized morphology, stable crystal structure, and improved ionic conductivity.
