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1.
Nanoscale surface‐engineering plays an important role in improving the performance of battery electrodes. Nb2O5 is one typical model anode material with promising high‐rate lithium storage. However, its modest reaction kinetics and low electrical conductivity obstruct the efficient storage of larger ions of sodium or potassium. In this work, partially surface‐amorphized and defect‐rich black niobium oxide@graphene (black Nb2O5?x@rGO) nanosheets are designed to overcome the above Na/K storage problems. The black Nb2O5?x@rGO nanosheets electrodes deliver a high‐rate Na and K storage capacity (123 and 73 mAh g?1, respectively at 3 A g?1) with long‐term cycling stability. Besides, both Na‐ion and K‐ion full batteries based on black Nb2O5?x@rGO nanosheets anodes and vanadate‐based cathodes (Na0.33V2O5 and K0.5V2O5 for Na‐ion and K‐ion full batteries, respectively) demonstrate promising rate and cycling performance. Notably, the K‐ion full battery delivers higher energy and power densities (172 Wh Kg?1 and 430 W Kg?1), comparable to those reported in state‐of‐the‐art K‐ion full batteries, accompanying with a capacity retention of ≈81.3% over 270 cycles. This result on Na‐/K‐ion batteries may pave the way to next‐generation post‐lithium batteries.  相似文献   

2.
V2O5 hollow microclews (V2O5‐HMs) have been fabricated through a facile solvothermal method with subsequent calcination. The synthesized V2O5‐HMs exhibit a 3D hierarchical structure constructed by intertangled nanowires, which could realize superior ion transport, good structural stability, and significantly improved tap density. When used as the cathodes for lithium‐ion batteries (LIBs), the V2O5‐HMs deliver a high capacity (145.3 mAh g‐1) and a superior rate capability (94.8 mAh g‐1 at 65 C). When coupled with a lithiated Li3VO4 anode, the all‐vanadium‐based lithium‐ion full cell exhibits remarkable cycling stability with a capacity retention of 71.7% over 1500 cycles at 6.7 C. The excellent electrochemical performance demonstrates that the V2O5‐HM is a promising candidate for LIBs. The insight obtained from this work also provides a novel strategy for assembling 1D materials into hierarchical microarchitectures with anti‐pulverization ability, excellent electrochemical kinetics, and enhanced tap density.  相似文献   

3.
Ti–Nb–O binary oxide materials represent a family of promising intercalating anode materials for lithium‐ion batteries. In additional to their excellent capacities (388–402 mAh g–1), these materials show excellent safety characteristics, such as an operating potential above the lithium plating voltage and minimal volume change. Herein, this study reports a new member in the Ti–Nb–O family, Ti2Nb14O39, as an advanced anode material. Ti2Nb14O39 porous spheres (Ti2Nb14O39‐S) exhibit a defective shear ReO3 crystal structure with a large unit cell volume and a large amount of cation vacancies (0.85% vs all cation sites). These morphological and structural characteristics allow for short electron/Li+‐ion transport length and fast Li+‐ion diffusivity. Consequently, the Ti2Nb14O39‐S material delivers significant pseudocapacitive behavior and excellent electrochemical performances, including high reversible capacity (326 mAh g?1 at 0.1 C), high first‐cycle Coulombic efficiency (87.5%), safe working potential (1.67 V vs Li/Li+), outstanding rate capability (223 mAh g–1 at 40 C) and durable cycling stability (only 0.032% capacity loss per cycle over 200 cycles at 10 C). These impressive results clearly demonstrate that Ti2Nb14O39‐S can be a promising anode material for fast‐charging, high capacity, safe and stable lithium‐ion batteries.  相似文献   

4.
Lithium metal batteries (such as lithium–sulfur, lithium–air, solid state batteries with lithium metal anode) are highly considered as promising candidates for next‐generation energy storage systems. However, the unstable interfaces between lithium anode and electrolyte definitely induce the undesired and uncontrollable growth of lithium dendrites, which results in the short‐circuit and thermal runaway of the rechargeable batteries. Herein, a dual‐layered film is built on a Li metal anode by the immersion of lithium plates into the fluoroethylene carbonate solvent. The ionic conductive film exhibits a compact dual‐layered feature with organic components (ROCO2Li and ROLi) on the top and abundant inorganic components (Li2CO3 and LiF) in the bottom. The dual‐layered interface can protect the Li metal anode from the corrosion of electrolytes and regulate the uniform deposition of Li to achieve a dendrite‐free Li metal anode. This work demonstrates the concept of rational construction of dual‐layered structured interfaces for safe rechargeable batteries through facile surface modification of Li metal anodes. This not only is critically helpful to comprehensively understand the functional mechanism of fluoroethylene carbonate but also affords a facile and efficient method to protect Li metal anodes.  相似文献   

5.
Improved conductivity and suppressed dissolution of lithium polysulfides is highly desirable for high‐performance lithium‐sulfur (Li‐S) batteries. Herein, by a facile solvent method followed by nitridation with NH3, a 2D nitrogen‐doped carbon structure is designed with homogeneously embedded Co4N nanoparticles derived from metal organic framework (MOF), grown on the carbon cloth (MOF‐Co4N). Experimental results and theoretical simulations reveal that Co4N nanoparticles act as strong chemical adsorption hosts and catalysts that not only improve the cycling performance of Li‐S batteries via chemical bonding to trap polysulfides but also improve the rate performance through accelerating the conversion reactions by decreasing the polarization of the electrode. In addition, the high conductive nitrogen‐doped carbon matrix ensures fast charge transfer, while the 2D structure offers increased pathways to facilitate ion diffusion. Under the current density of 0.1C, 0.5C, and 3C, MOF‐Co4N delivers reversible specific capacities of 1425, 1049, and 729 mAh g?1, respectively, and retains 82.5% capacity after 400 cycles at 1C, as compared to the sample without Co4N (MOF‐C) values of 61.3% (200 cycles). The improved cell performance corroborates the validity of the multifunctional design of MOF‐Co4N, which is expected to be a potentially promising cathode host for Li‐S batteries.  相似文献   

6.
As soluble catalysts, redox‐mediators (RMs) endow mobility to catalysts for unconstrained access to tethered solid discharge products, lowering the energy barrier for Li2O2 formation/decomposition; however, this desired mobility is accompanied by the undesirable side effect of RM migration to the Li metal anode. The reaction between RMs and Li metal degrades both the Li metal and the RMs, leading to cell deterioration within a few cycles. To extend the cycle life of redox‐mediated Li–O2 batteries, herein graphene oxide (GO) membranes are reported as RM‐blocking separators. It is revealed that the size of GO nanochannels is narrow enough to reject 5,10‐dihydro‐5,10‐dimethylphenazine (DMPZ) while selectively allowing the transport of smaller Li+ ions. The negative surface charges of GO further repel negative ions via Donnan exclusion, greatly improving the lithium ion transference number. The Li–O2 cells with GO membranes efficiently harness the redox‐mediation activity of DMPZ for improved performance, achieving energy efficiency of above 80% for more than 25 cycles, and 90% for 78 cycles when the capacity limits were 0.75 and 0.5 mAh cm‐2, respectively. Considering the facile preparation of GO membranes, RM‐sieving GO membranes can be cost‐effective and processable functional separators in Li–O2 batteries.  相似文献   

7.
The safety hazards and cycle instability of lithium metal anodes (LMA) constitute significant barriers to progress in lithium metal batteries. This situation is worse in Li–O2 batteries because the LMA is prone to be chemically attacked by O2 shuttled from the cathode. Notwithstanding, efforts on LMA are much sparse than those on the cathode in the realm of Li–O2 batteries. Here, a novel lithium salt of Li[(CF3SO2)(n‐C4F9SO2)N] (LiTNFSI) is reported, which can effectively suppress the parasitic side reactions and dendrite growth of LMA during cycling and thereby significantly enhance the overall reversibility of Li–O2 batteries. A variety of advanced research tools are employed to scrutinize the working principles of the LiTNFSI salt. It is revealed that a stable, uniform, and O2‐resistive solid electrolyte interphase is formed on LMA, and hence the “cross‐talk” between the LMA and O2 shuttled from the cathode is remarkably inhibited in LiTNFSI‐based Li–O2 batteries.  相似文献   

8.
To achieve a high reversibility and long cycle life for Li–O2 battery system, the stable tissue‐directed/reinforced bifunctional separator/protection film (TBF) is in situ fabricated on the surface of metallic lithium anode. It is shown that a Li–O2 cell composed of the TBF‐modified lithium anodes exhibits an excellent anodic reversibility (300 cycles) and effectively improved cathodic long lifetime (106 cycles). The improvement is attributed to the ability of the TBF, which has chemical, electrochemical, and mechanical stability, to effectively prevent direct contact between the surface of the lithium anode and the highly reactive reduced oxygen species (Li2O2 or its intermediate LiO2) in cell. It is believed that the protection strategy describes here can be easily extended to other next‐generation high energy density batteries using metal as anode including Li–S and Na–O2 batteries.  相似文献   

9.
The pursuit for high‐energy‐density batteries has inspired the resurgence of metallic lithium (Li) as a promising anode, yet its practical viability is restricted by the uncontrollable Li dendrite growth and huge volume changes during repeated cycling. Herein, a new 3D framework configured with Mo2N‐mofidied carbon nanofiber (CNF) architecture is established as a Li host via a facile fabrication method. The lithiophilic Mo2N acts as a homogeneously pre‐planted seed with ultralow Li nucleation overpotential, thus spatially guiding a uniform Li nucleation and deposition in the matrix. The conductive CNF skeleton effectively homogenizes the current distribution and Li‐ion flux, further suppressing Li‐dendrite formation. As a result, the 3D hybrid Mo2N@CNF structure facilitates a dendrite‐free morphology with greatly alleviated volume expansion, delivering a significantly improved Coulombic efficiency of ≈99.2% over 150 cycles at 4 mA cm?2. Symmetric cells with Mo2N@CNF substrates stably operate over 1500 h at 6 mA cm?2 for 6 mA h cm?2. Furthermore, full cells paired with LiNi0.8Co0.1Mn0.1O2 (NMC811) cathodes in conventional carbonate electrolytes achieve a remarkable capacity retention of 90% over 150 cycles. This work sheds new light on the facile design of 3D lithiophilic hosts for dendrite‐free lithium‐metal anodes.  相似文献   

10.
Rechargeable aprotic lithium (Li)–O2 batteries with high theoretical energy densities are regarded as promising next‐generation energy storage devices and have attracted considerable interest recently. However, these batteries still suffer from many critical issues, such as low capacity, poor cycle life, and low round‐trip efficiency, rendering the practical application of these batteries rather sluggish. Cathode catalysts with high oxygen reduction reaction (ORR) and evolution reaction activities are of particular importance for addressing these issues and consequently promoting the application of Li–O2 batteries. Thus, the rational design and preparation of the catalysts with high ORR activity, good electronic conductivity, and decent chemical/electrochemical stability are still challenging. In this Review, the strategies are outlined including the rational selection of catalytic species, the introduction of a 3D porous structure, the formation of functional composites, and the heteroatom doping which succeeded in the design of high‐performance cathode catalysts for stable Li–O2 batteries. Perspectives on enhancing the overall electrochemical performance of Li–O2 batteries based on the optimization of the properties and reliability of each part of the battery are also made. This Review sheds some new light on the design of highly active cathode catalysts and the development of high‐performance lithium–O2 batteries.  相似文献   

11.
The practical applications of lithium–sulfur (Li–S) batteries are seriously limited by the undesirable polysulfide shuttling and lithium dendrite growth. Herein, a multifunctional membrane is designed and prepared by coating a lithiated Nafion (Li@Nafion) layer and an Al2O3 layer on the two sides of a routine polymer membrane (polypropylene/polyethylene/polypropylene, PEP). The Li@Nafion layer faced to the sulfur cathode builds a “polysulfide‐phobic” surface to restrain the shuttle effect via Coulomb repulsion, while the Al2O3 layer with a uniform porous structure aids in regulating homogeneous Li+ fluxes to achieve stable Li electrodeposition. As a result, the Li//Li symmetric cell with a Li@Nafion/PEP/Al2O3 (LNPA) separator realizes stable Li plating/striping even after 1000 h at a high current density (5 mA cm?2). Moreover, the Li–S batteries incorporating LNPA separators not only can achieve excellent outstanding cyclic stability at an ultrahigh sulfur loading (7.6 mg cm?2), but also exhibit impressive electrochemical performance at an elevated temperature (60 °C). The rational design of the LNPA separator presents new insights to develop high‐performance Li–S batteries.  相似文献   

12.
Lithium metal is an ultimate anode in “next‐generation” rechargeable batteries, such as Li–sulfur batteries and Li–air (Li–O2) batteries. However, uncontrollable dendritic Li growth and water attack have prevented its practical applications, especially for open‐system Li–O2 batteries. Here, it is reported that the issues can be addressed via the facile process of immersing the Li metal in organic GeCl4–THF steam for several minutes before battery assembly. This creates a 1.5 µm thick protection layer composed of Ge, GeOx, Li2CO3, LiOH, LiCl, and Li2O on Li surface that allows stable cycling of Li electrodes both in Li‐symmetrical cells and Li–O2 cells, especially in “moist” electrolytes (with 1000–10 000 ppm H2O) and humid O2 atmosphere (relative humidity (RH) of 45%). This work illustrates a simple and effective way for the unfettered development of Li‐metal‐based batteries.  相似文献   

13.
Recent advances and achievements in emerging Li‐X (X = O2, S, Se, Te, I2, Br2) batteries with promising cathode materials open up new opportunities for the development of high‐performance lithium‐ion battery alternatives. In this review, we focus on an overview of recent important progress in the design of advanced cathode materials and battery models for developing high‐performance Li‐X (X = O2, S, Se, Te, I2, Br2) batteries. We start with a brief introduction to explain why Li‐X batteries are important for future renewable energy devices. Then, we summarize the existing drawbacks, major progress and emerging challenges in the development of cathode materials for Li‐O2 (S) batteries. In terms of the emerging Li‐X (Se, Te, I2, Br2) batteries, we systematically summarize their advantages/disadvantages and recent progress. Specifically, we review the electrochemical performance of Li‐Se (Te) batteries using carbonate‐/ether‐based electrolytes, made with different electrode fabrication techniques, and of Li‐I2 (Br2) batteries with various cell designs (e.g., dual electrolyte, all‐organic electrolyte, with/without cathode‐flow mode, and fuel cell/solar cell integration). Finally, the perspective on and challenges for the development of cathode materials for the promising Li‐X (X = O2, S, Se, Te, I2, Br2) batteries is presented.  相似文献   

14.
Lithium–sulfur batteries (LSBs) have shown great potential for application in high‐density energy storage systems. However, the performance of LSBs is hindered by the shuttle effect and sluggish reaction kinetics of lithium polysulfides (LiPSs). Herein, heterostructual Nb2O5 nanocrystals/reduced graphene oxide (Nb2O5/RGO) composites are introduced into LSBs through separator modification for boosting the electrochemical performance. The Nb2O5/RGO heterostructures are designed as chemical trappers and conversion accelerators of LiPSs. Originating from the strong chemical interactions between Nb2O5 and LiPSs as well as the superior catalytic nature of Nb2O5, the Nb2O5/RGO nanocomposite possesses high trapping efficiency and efficient electrocatalytic activity to long‐chain LiPSs. The effective regulation of LiPSs conversion enables the LSBs enhanced redox kinetics and suppressed shuttle effect. Moreover, the Nb2O5/RGO nanocomposite has abundant sulfophilic sites and defective interfaces, which are beneficial for the nucleation and growth of Li2S, as evidenced by analysis of the cycled separators. As a result, LSBs with the Nb2O5/RGO‐modified separators exhibit excellent rate capability (816 mAh g?1 at 3 A g?1) and cyclic performance (628 mAh g?1 after 500 cycles). Remarkably, high specific capacity and stable cycling performance are demonstrated even at an elevated temperature of 50 °C or with higher sulfur loadings.  相似文献   

15.
Sodium‐ion hybrid supercapacitors (Na‐HSCs) by virtue of synergizing the merits of batteries and supercapacitors have attracted considerable attention for high‐energy and high‐power energy‐storage applications. Orthorhombic Nb2O5 (T‐Nb2O5) has recently been recognized as a promising anode material for Na‐HSCs due to its typical pseudocapacitive feature, but it suffers from intrinsically low electrical conductivity. Reasonably high electrochemical performance of T‐Nb2O5‐based electrodes could merely be gained to date when sufficient carbon content was introduced. In addition, flexible Na‐HSC devices have scarcely been demonstrated by far. Herein, an in situ encapsulation strategy is devised to directly grow ultrathin graphene shells over T‐Nb2O5 nanowires (denoted as Gr‐Nb2O5 composites) by plasma‐enhanced chemical vapor deposition, targeting a highly conductive anode material for Na‐HSCs. The few‐layered graphene capsules with ample topological defects would enable facile electron and Na+ ion transport, guaranteeing rapid pseudocapacitive processes at the Nb2O5/electrolyte interface. The Na‐HSC full‐cell comprising a Gr‐Nb2O5 anode and an activated carbon cathode delivers high energy/power densities (112.9 Wh kg?1/80.1 W kg?1 and 62.2 Wh kg?1/5330 W kg?1), outperforming those of recently reported Na‐HSC counterparts. Proof‐of‐concept Na‐HSC devices with favorable mechanical robustness manifest stable electrochemical performances under different bending conditions and after various bending–release cycles.  相似文献   

16.
Niobium‐based oxides including Nb2O5, TiNbxO2+2.5x compounds, M–Nb–O (M = Cr, Ga, Fe, Zr, Mg, etc.) family, etc., as the unique structural merit (e.g., quasi‐2D network for Li‐ion incorporation, open and stable Wadsley– Roth shear crystal structure), are of great interest for applications in energy storage systems such as Li/Na‐ion batteries and hybrid supercapacitors. Most of these Nb‐based oxides show high operating voltage (>1.0 V vs Li+/Li) that can suppress the formation of solid electrolyte interface film and lithium dendrites, ensuring the safety of working batteries. Outstanding rate capability is impressive, which can be derived from their fast intercalation pseudocapacitive kinetics. However, the intrinsic poor electrical conductivity hinders their energy storage applications. Various strategies including structure optimization, surface engineering, and carbon modification are effectively used to overcome the issues. This review provides a comprehensive summary on the latest progress of Nb‐based oxides for advanced electrochemical energy storage applications. Major impactful work is outlined, promising research directions, and various performance‐optimizing strategies, as well as the energy storage mechanisms investigated by combining theoretical calculations and various electrochemical characterization techniques. In addition, challenges and perspectives for future research and commercial applications are also presented.  相似文献   

17.
In this study, self‐synthesized lithium trifluoro(perfluoro‐tert‐butyloxyl)borate (LiTFPFB) is combined with lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) to formulate a novel 1 m dual‐salt electrolyte, which contains lithium difluorophosphate (LiPO2F2) additive and dominant carbonate solvents with low melting point and high boiling point. The addition of LiPO2F2 into this novel dual‐salt electrolyte dramatically improves cycleability and rate capability of a LiNi0.5Mn0.3Co0.2O2/Li (NMC/Li) battery, ranging from ?40 to 90 °C. The NMC/Li batteries adopt a Li–metal anode with low thickness of 100 µm (even 50 µm) and a moderately high cathode mass loading level of 10 mg cm?2. For the first time, this paper provides valuable perspectives for developing practical lithium–metal batteries over a wide temperature range.  相似文献   

18.
The lithium (Li) metal anode is confronted by severe interfacial issues that strongly hinder its practical deployment. The unstable interfaces directly induce unfavorable low cycling efficiency, dendritic Li deposition, and even strong safety concerns. An advanced artificial protective layer with single‐ion pathways holds great promise for enabling a spatially homogeneous ionic and electric field distribution over Li metal surface, therefore well protecting the Li metal anode during long‐term working conditions. Herein, a robust dual‐phase artificial interface is constructed, where not only the single‐ion‐conducting nature, but also high mechanical rigidity and considerable deformability can be fulfilled simultaneously by the rational integration of a garnet Al‐doped Li6.75La3Zr1.75Ta0.25O12‐based bottom layer and a lithiated Nafion top layer. The as‐constructed artificial solid electrolyte interphase is demonstrated to significantly stabilize the repeated cell charging/discharging process via regulating a facile Li‐ion transport and a compact Li plating behavior, hence contributing to a higher coulombic efficiency and a considerably enhanced cyclability of lithium metal batteries. This work highlights the significance of rational manipulation of the interfacial properties of a working Li metal anode and affords fresh insights into achieving dendrite‐free Li deposition behavior in a working battery.  相似文献   

19.
The aprotic Li–O2 battery has attracted a great deal of interest because theoretically it can store more energy than today's Li‐ion batteries. However, current Li–O2 batteries suffer from passivation/clogging of the cathode by discharged Li2O2, high charging voltage for its subsequent oxidation, and accumulation of side reaction products (particularly Li2CO3 and LiOH) upon cycling. Here, an advanced Li–O2 battery with a hexamethylphosphoramide (HMPA) electrolyte is reported that can dissolve Li2O2, Li2CO3, and LiOH up to 0.35, 0.36, and 1.11 × 10?3m , respectively, and a LiPON‐protected lithium anode that can be reversibly cycled in the HMPA electrolyte. Compared to the benchmark of ether‐based Li–O2 batteries, improved capacity, rate capability, voltaic efficiency, and cycle life are achieved for the HMPA‐based Li–O2 cells. More importantly, a combination of advanced research techniques provide compelling evidence that operation of the HMPA‐based Li–O2 battery is backed by nearly reversible formation/decomposition of Li2O2 with negligible side reactions.  相似文献   

20.
Owing to the high theoretical specific capacity (1675 mA h g?1) and low cost, lithium–sulfur (Li–S) batteries offer advantages for next‐generation energy storage. However, the polysulfide dissolution and low electronic conductivity of sulfur cathodes limit the practical application of Li–S batteries. To address such issues, well‐designed yolk–shelled carbon@Fe3O4 (YSC@Fe3O4) nanoboxes as highly efficient sulfur hosts for Li–S batteries are reported here. With both physical entrapment by carbon shells and strong chemical interaction with Fe3O4 cores, this unique architecture immobilizes the active material and inhibits diffusion of the polysulfide intermediates. Moreover, due to their high conductivity, the carbon shells and the polar Fe3O4 cores facilitate fast electron/ion transport and promote continuous reactivation of the active material during the charge/discharge process, resulting in improved electrochemical utilization and reversibility. With these merits, the S/YSC@Fe3O4 cathodes support high sulfur content (80 wt%) and loading (5.5 mg cm?2) and deliver high specific capacity, excellent rate capacity, and long cycling stability. This work provides a new perspective to design a carbon/metal‐oxide‐based yolk–shelled framework as a high sulfur‐loading host for advanced Li–S batteries with superior electrochemical properties.  相似文献   

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