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1.
Aqueous Zn‐ion batteries (ZIBs) have received incremental attention because of their cost‐effectiveness and the materials abundance. They are a promising choice for large‐scale energy storage applications. However, developing suitable cathode materials for ZIBs remains a great challenge. In this work, pioneering work on the designing and construction of aqueous Zn//Na0.33V2O5 batteries is reported. The Na0.33V2O5 (NVO) electrode delivers a high capacity of 367.1 mA h g?1 at 0.1 A g?1, and exhibits long‐term cyclic stability with a capacity retention over 93% for 1000 cycles. The improvement of electrical conductivity, resulting from the intercalation of sodium ions between the [V4O12]n layers, is demonstrated by single nanowire device. Furthermore, the reversible intercalation reaction mechanism is confirmed by X‐ray diffraction, Raman, X‐ray photoelectron spectroscopy, scanning electron microscopy, and transmission electron microscopy analysis. The outstanding performance can be attributed to the stable layered structure and high conductivity of NVO. This work also indicates that layered structural materials show great potential as the cathode of ZIBs, and the indigenous ions can act as pillars to stabilize the layered structure, thereby ensuring an enhanced cycling stability.  相似文献   

2.
Rechargeable aqueous zinc‐ion batteries (ZIBs) have been emerging as potential large‐scale energy storage devices due to their high energy density, low cost, high safety, and environmental friendliness. However, the commonly used cathode materials in ZIBs exhibit poor electrochemical performance, such as significant capacity fading during long‐term cycling and poor performance at high current rates, which significantly hinder the further development of ZIBs. Herein, a new and highly reversible Mn‐based cathode material with porous framework and N‐doping (MnOx@N‐C) is prepared through a metal–organic framework template strategy. Benefiting from the unique porous structure, conductive carbon network, and the synergetic effect of Zn2+ and Mn2+ in electrolyte, the MnOx@N‐C shows excellent cycling stability, good rate performance, and high reversibility for aqueous ZIBs. Specifically, it exhibits high capacity of 305 mAh g?1 after 600 cycles at 500 mA g?1 and maintains achievable capacity of 100 mAh g?1 at a quite high rate of 2000 mA g?1 with long‐term cycling of up to 1600 cycles, which are superior to most reported ZIB cathode materials. Furthermore, insight into the Zn‐storage mechanism in MnOx@N‐C is systematically studied and discussed via multiple analytical methods. This study opens new opportunities for designing low‐cost and high‐performance rechargeable aqueous ZIBs.  相似文献   

3.
Aqueous batteries are facing big challenges in the context of low working voltages and energy density, which are dictated by the narrow electrochemical window of aqueous electrolytes and low specific capacities of traditional intercalation‐type electrodes, even though they usually represent high safety, low cost, and simple maintenance. For the first time, this work demonstrates a record high‐energy‐density (1503 Wh kg?1 calculated from the cathode active material) aqueous battery system that derives from a novel electrolyte design to expand the electrochemical window of electrolyte to 3 V and two high‐specific‐capacity electrode reactions. An acid‐alkaline dual electrolyte separated by an ion‐selective membrane enables two dissolution/deposition electrode redox reactions of MnO2/Mn2+ and Zn/Zn(OH)42? with theoretical specific capacities of 616 and 820 mAh g?1, respectively. The newly proposed Zn–Mn2+ aqueous battery shows a high Coulombic efficiency of 98.4% and cycling stability of 97.5% of discharge capacity retention for 1500 cycles. Furthermore, in the flow battery based on Zn–Mn2+ pairs, more excellent stability of 99.5% of discharge capacity retention for 6000 cycles is achieved due to greatly improved reversibility of the Zn anode. This work provides a new path for the development of novel aqueous batteries with high voltage and energy density.  相似文献   

4.
Rechargeable aqueous zinc‐ion batteries (ZIBs) are appealing due to their high safety, zinc abundance, and low cost. However, developing suitable cathode materials remains a great challenge. Herein, a novel 2D heterostructure of ultrathin amorphous vanadium pentoxide uniformly grown on graphene (A‐V2O5/G) with a very short ion diffusion pathway, abundant active sites, high electrical conductivity, and exceptional structural stability, is demonstrated for highly reversible aqueous ZIBs (A‐V2O5/G‐ZIBs), coupling with unprecedented high capacity, rate capability, long‐term cyclability, and excellent safety. As a result, 2D A‐V2O5/G heterostructures for stacked ZIBs at 0.1 A g?1 display an ultrahigh capacity of 489 mAh g?1, outperforming all reported ZIBs, with an admirable rate capability of 123 mAh g?1 even at 70 A g?1. Furthermore, the new‐concept prototype planar miniaturized zinc‐ion microbatteries (A‐V2O5/G‐ZIMBs), demonstrate a high volumetric capacity of 20 mAh cm?3 at 1 mA cm?2, long cyclability; holding high capacity retention of 80% after 3500 cycles, and in‐series integration, demonstrative of great potential for highly‐safe microsized power sources. Therefore, the exploration of such 2D heterostructure materials with strong synergy is a reliable strategy for developing safe and high‐performance energy storage devices.  相似文献   

5.
Achieving high‐performance Na‐ion capacitors (NICs) has the particular challenge of matching both capacity and kinetics between the anode and cathode. Here a high‐power NIC full device constructed from 2D metal–organic framework (MOFs) array is reported as the reactive template. The MOF array is converted to N‐doped mesoporous carbon nanosheets (mp‐CNSs), which are then uniformly encapsulated with VO2 and Na3V2(PO4)3 (NVP) nanoparticles as the electroactive materials. By this method, the high‐power performance of the battery materials is enabled to be enhanced significantly. It is discovered that such hybrid NVP@mp‐CNSs array can render ultrahigh rate capability (up to 200 C, equivalent to discharge within 18 s) and superior cycle performance, which outperforms all NVP‐based Na‐ion battery cathodes reported so far. A quasi‐solid‐state flexible NIC based on the NVP@mp‐CNSs cathode and the VO2@mp‐CNSs anode is further assembled. This hybrid NIC device delivers both high energy density and power density as well as a good cycle stability (78% retention after 2000 cycles at 1 A g?1). The results demonstrate the powerfulness of MOF arrays as the reactor for fabricating electrode materials.  相似文献   

6.
Rechargeable aqueous Zn‐based batteries are attractive candidates as energy storage technology, but the uncontrollable Zn dendrites, low stripping/plating coulombic efficiency, and inefficient utilization of Zn metal limit the battery reliability and energy density. Herein, for the first time, a novel presodiated TiS2 (Na0.14TiS2) is proposed and investigated as an intercalated anode for aqueous Zn‐ion batteries, showing a capacity of 140 mAh g?1 with a suitable potential of 0.3 V (vs Zn2+/Zn) at 0.05 A g?1 and superior cyclability of 77% retention over 5000 cycles at 0.5 A g?1. The remarkable performance originates from the buffer phase formation of Na0.14TiS2 after chemically presodiating TiS2, which not only improves the structural reversibility and stability but also enhances the diffusion coefficient and electronic conductivity, and lowers cation migration barrier, as evidenced by a series of experimental and theoretical studies. Moreover, an aqueous “rocking‐chair” Zn‐ion full battery is successfully demonstrated by this Na0.14TiS2 anode and ZnMn2O4 cathode, which delivers a capacity of 105 mAh g?1 (for anode) with an average voltage of 0.95 V at 0.05 A g?1 and preserves 74% retention after 100 cycles at 0.2 A g?1, demonstrating the feasibility of Zn‐ion full batteries for energy storage applications.  相似文献   

7.
Rechargeable aqueous batteries with Zn2+ as a working‐ion are promising candidates for grid‐scale energy storage because of their intrinsic safety, low‐cost, and high energy‐intensity. However, suitable cathode materials with excellent Zn2+‐storage cyclability must be found in order for Zinc‐ion batteries (ZIBs) to find practical applications. Herein, NaCa0.6V6O16·3H2O (NaCaVO) barnesite nanobelts are reported as an ultra‐stable ZIB cathode material. The original capacity reaches 347 mAh g?1 at 0.1 A g?1, and the capacity retention rate is 94% after 2000 cycles at 2 A g?1 and 83% after 10 000 cycles at 5 A g?1, respectively. Through a combined theoretical and experimental approach, it is discovered that the unique V3O8 layered structure in NaCaVO is energetically favorable for Zn2+ diffusion and the structural water situated between V3O8 layers promotes a fast charge‐transfer and bulk migration of Zn2+ by enlarging gallery spacing and providing more Zn‐ion storage sites. It is also found that Na+ and Ca2+ alternately suited in V3O8 layers are the essential stabilizers for the layered structure, which play a crucial role in retaining long‐term cycling stability.  相似文献   

8.
With the rapidly growing demand for low‐cost and safe energy storage, the advanced battery concepts have triggered strong interests beyond the state‐of‐the‐art Li‐ion batteries (LIBs). Herein, a novel hybrid Li/Na‐ion full battery (HLNIB) composed of the high‐energy and lithium‐free Na3V2(PO4)2O2F (NVPOF) cathode and commercial graphite anode mesophase carbon micro beads is for the first time designed. The assembled HLNIBs exhibit two high working voltage at about 4.05 and 3.69 V with a specific capacity of 112.7 mA h g?1. Its energy density can reach up to 328 W h kg?1 calculated from the total mass of both cathode and anode materials. Moreover, the HLNIBs show outstanding high‐rate capability, long‐term cycle life, and excellent low‐temperature performance. In addition, the reaction kinetics and Li/Na‐insertion/extraction mechanism into/out NVPOF is preliminarily investigated by the galvanostatic intermittent titration technique and ex situ X‐ray diffraction. This work provides a new and profound direction to develop advanced hybrid batteries.  相似文献   

9.
While 2D MXenes have been widely used in energy storage systems, surface barriers induced by restacking of nanosheets and the limited kinetics resulting from insufficient interlayer spacing are two unresolved issues. Here an Sn4+ preintercalated Ti2CTX with effectively enlarged interlayer spacing is synthesized. The preintercalated Ti2CTX is aligned on a carbon sphere to further enhance ion transportation by shortening the ion diffusion path and enhancing the reaction kinetics. As a result, when paired with a Zn anode, 12 500 cycles, which equals 2 800 h cycle time, and 5% capacity fluctuation are obtained, surpassing all reported MXene‐based aqueous electrodes. At 0.1 A g‐1, the capacity reaches 138 mAh g‐1, and 92 mAh g‐1 remains even at 5 A g‐1. In addition, the low anti‐self‐discharge rate of 0.989 mV h‐1 associated with a high capacity retention of 80.5% over 548 h is obtained. Moreover, the fabricated quasi‐solid capacitor based on a hydrogel film electrolyte exhibits good mechanical deformation and weather resistance. This work employs both preintercalation and alignment to MXene and achieves enhanced ion diffusion kinetics in an aqueous zinc ion capacitors (ZICs) system, which may be applied to other MXene batteries for enhanced performance.  相似文献   

10.
Potassium‐ion batteries are attracting great interest for emerging large‐scale energy storage owing to their advantages such as low cost and high operational voltage. However, they are still suffering from poor cycling stability and sluggish thermodynamic kinetics, which inhibits their practical applications. Herein, the synthesis of hierarchical K1.39Mn3O6 microspheres as cathode materials for potassium‐ion batteries is reported. Additionally, an effective AlF3 surface coating strategy is applied to further improve the electrochemical performance of K1.39Mn3O6 microspheres. The as‐synthesized AlF3 coated K1.39Mn3O6 microspheres show a high reversible capacity (about 110 mA h g?1 at 10 mA g?1), excellent rate capability, and cycling stability. Galvanostatic intermittent titration technique results demonstrate that the increased diffusion kinetics of potassium‐ion insertion and extraction during discharge and charge processes benefit from both the hierarchical sphere structure and surface modification. Furthermore, ex situ X‐ray diffraction measurements reveal that the irreversible structure evolution can be significantly mitigated via surface modification. This work sheds light on rational design of high‐performance cathode materials for potassium‐ion batteries.  相似文献   

11.
Rechargeable aqueous Zn/MnO2 batteries are very attractive large‐scale energy storage technologies, but still suffer from limited cycle life and low capacity. Here the novel adoption of a near‐neutral acetate‐based electrolyte (pH ≈ 6) is presented to promote the two‐electron Mn4+/Mn2+ redox reaction and simultaneously enable a stable Zn anode. The acetate anion triggers a highly reversible MnO2/Mn2+ reaction, which ensures high capacity and avoids the issue of structural collapse of MnO2. Meanwhile, the anode‐friendly electrolyte enables a dendrite‐free Zn anode with outstanding stability and high plating/stripping Coulombic efficiency (99.8%). Hence, a high capacity of 556 mA h g?1, a lifetime of 4000 cycles without decay, and excellent rate capability up to 70 mA cm?2 are demonstated in this new near‐neutral aqueous Zn/MnO2 battery by simply manipulating the salt anion in the electrolyte. The acetate anion not only modifies the surface properties of MnO2 cathode but also creates a highly compatible environment for the Zn anode. This work provides a new opportunity for developing high‐performance Zn/MnO2 and other aqueous batteries based on the salt anion chemistry.  相似文献   

12.
Aqueous zinc ion batteries (AZIBs) are steadily gaining attention based on their attractive merits regarding cost and safety. However, there are many obstacles to overcome, especially in terms of finding suitable cathode materials and elucidating their reaction mechanisms. Here, a mixed‐valence vanadium oxide, V6O13, that functions as a stable cathode material in mildly acidic aqueous electrolytes is reported. Paired with a zinc metal anode, this material exhibits performance metrics of 360 mAh g?1 at 0.2 A g?1, 92% capacity retention after 2000 cycles, and 145 mAh g?1 at a current density of 24.0 A g?1. A combination of experiments and density functional theory calculations suggests that hydrated intercalation, where water molecules are cointercalated with Zn ions upon discharge, accounts for the aforementioned electrochemical performance. This intercalation mechanism facilitates Zn ion diffusion throughout the host lattice and electrode–electrolyte interface via electrostatic shielding and concurrent structural stabilization. Through a correlation of experimental data and theoretical calculations, the promise of utilizing hydrated intercalation as a means to achieve high‐performance AZIBs is demonstrated.  相似文献   

13.
Aqueous zinc batteries are considered as promising alternatives to lithium ion batteries owing to their low cost and high safety. However, the developments of state‐of‐the‐art zinc‐ion batteries (ZIB) and zinc–air batteries (ZAB) are limited by the unsatisfied capacities and poor cycling stabilities, respectively. It is of significance in utilizing the long‐cycle life of ZIB and high capacity of ZAB to exploit advanced energy storage systems. Herein, a bulk composite of graphene oxide and vanadium oxide (V5O12·6H2O) as cathode material for aqueous Zn batteries in a mild electrolyte is employed. The battery performance is demonstrated to arise from a combination of the reversible cations insertion/extraction in vanadium oxide and especially the electrochemical redox reactions on the surface functional groups of graphene oxide (named as pseudo‐Zn–air mechanism). Along with adjusting the hydroxyl content on the surface of graphene oxide, the specific capacity is significantly increased from 342 mAh g?1 to a maximum of 496 mAh g?1 at 100 mA g?1. The surface‐controlled kinetics occurring in the bulk composite ensure a high areal capacity of 10.6 mAh cm?2 at a mass loading of 26.5 mg cm?2, and a capacity retention of 84.7% over 10 000 cycles at a high current density of 10 A g?1.  相似文献   

14.
Herein, a new P2‐type layered oxide is proposed as an outstanding intercalation cathode material for high energy density sodium‐ion batteries (SIBs). On the basis of the stoichiometry of sodium and transition metals, the P2‐type Na0.55[Ni0.1Fe0.1Mn0.8]O2 cathode is synthesized without impurities phase by partially substituting Ni and Fe into the Mn sites. The partial substitution results in a smoothing of the electrochemical charge/discharge profiles and thus greatly improves the battery performance. The P2‐type Na0.55[Ni0.1Fe0.1Mn0.8]O2 cathode delivers an extremely high discharge capacity of 221.5 mAh g?1 with a high average potential of ≈2.9 V (vs Na/Na+) for SIBs. In addition, the fast Na‐ion transport in the P2‐type Na0.55[Ni0.1Fe0.1Mn0.8]O2 cathode structure enables good power capability with an extremely high current density of 2400 mA g?1 (full charge/discharge in 12 min) and long‐term cycling stability with ≈80% capacity retention after 500 cycles at 600 mA g?1. A combination of electrochemical profiles, in operando synchrotron X‐ray diffraction analysis, and first‐principles calculations are used to understand the overall Na storage mechanism of P2‐type Na0.55[Ni0.1Fe0.1Mn0.8]O2.  相似文献   

15.
The traditional Zn/MnO2 battery has attracted great interest due to its low cost, high safety, high output voltage, and environmental friendliness. However, it remains a big challenge to achieve long‐term stability, mainly owing to the poor reversibility of the cathode reaction. Different from previous studies where the cathode redox reaction of MnO2/MnOOH is in solid state with limited reversibility, here a new aqueous rechargeable Zn/MnO2 flow battery is constructed with dissolution–precipitation reactions in both cathodes (Mn2+/MnO2) and anodes (Zn2+/Zn), which allow mixing of anolyte and catholyte into only one electrolyte and remove the requirement for an ion selective membrane for cost reduction. Impressively, this new battery exhibits a high discharge voltage of ≈1.78 V, good rate capability (10C discharge), and excellent cycling stability (1000 cycles without decay) at the areal capacity ranging from 0.5 to 2 mAh cm‐2. More importantly, this battery can be readily enlarged to a bench scale flow cell of 1.2 Ah with good capacity retention of 89.7% at the 500th cycle, displaying great potential for large‐scale energy storage.  相似文献   

16.
Potassium ion hybrid capacitors have great potential for large‐scale energy devices, because of the high power density and low cost. However, their practical applications are hindered by their low energy density, as well as electrolyte decomposition and collector corrosion at high potential in potassium bis(fluoro‐sulfonyl)imide‐based electrolyte. Therefore, anode materials with high capacity, a suitable voltage platform, and stability become a key factor. Here, N‐doping carbon‐coated FeSe2 clusters are demonstrated as the anode material for a hybrid capacitor, delivering a reversible capacity of 295 mAh g?1 at 100 mA g?1 over 100 cycles and a high rate capability of 158 mAh g?1 at 2000 mA g?1 over 2000 cycles. Meanwhile, through density functional theory calculations, in situ X‐ray diffraction, and ex situ transmission electron microscopy, the evolution of FeSe2 to Fe3Se4 for the electrochemical reaction mechanism is successfully revealed. The battery‐supercapacitor hybrid using commercial activated carbon as the cathode and FeSe2/N‐C as the anode is obtained. It delivers a high energy density of 230 Wh kg?1 and a power density of 920 W kg?1 (the energy density and power density are calculated based on the total mass of active materials in the anode and cathode).  相似文献   

17.
Despite great progress in aluminum ion batteries (AIBs), the commercialization and performance improvement of AIBs‐based carbon cathodes is greatly impeded by sluggish intercalation/extraction and redox kinetics due to large‐sized AlCl4? anions. Phosphates with tunnel channels and much larger d‐spacing than the radius of Al3+ could be an alternative candidate as a cathode for potential high‐performance AIBs. Herein, elaborately designed porous tunnel structured Co3(PO4)2@C composites derived from ZIF‐67 as AIBs cathodes are demonstrated, showing increased active sites, high ionic mobility, and high Al3+ ion diffusion coefficient, leading to remarkably enhanced discharge–charge redox reaction kinetics. Furthermore, the carbon shell and porous structure performs as armor to alleviate volume change and maintain the structure integrity of the cathodes. As expected, the rationally constructed Co3(PO4)2@C composite exhibits a superior capacity of 111 mA h g?1 at a high current density of 6 A g?1 and 151 mA h g?1 at 2 A g?1 after 500 cycles with capacity decay of 0.02% per cycle. This innovative strategy could be a big step forward for long‐term cycle stable AIBs and reveals significant insights into the redox reaction mechanism for high‐performance AIBs based on Al3+ rather than large‐sized AlCl4?.  相似文献   

18.
Zn‐based batteries are safe, low cost, and environmentally friendly, as well as delivering the highest energy density of all aqueous battery systems. However, the application of Zn‐based batteries is being seriously hindered by the uneven electrostripping/electroplating of Zn on the anodes, which always leads to enlarged polarization (capacity fading) or even cell shorting (low cycling stability). How a porous nano‐CaCO3 coating can guide uniform and position‐selected Zn stripping/plating on the nano‐CaCO3‐layer/Zn foil interfaces is reported here. This Zn‐deposition‐guiding ability is mainly ascribed to the porous nature of the nano‐CaCO3‐layer, since similar functionality (even though relatively inferior) is also found in Zn foils coated with porous acetylene black or nano‐SiO2 layers. Furthermore, the potential application of this strategy is demonstrated in Zn|ZnSO4+MnSO4|CNT/MnO2 rechargeable aqueous batteries. Compared with the ones with bare Zn anodes, the battery with a nano‐CaCO3‐coated Zn anode delivers a 42.7% higher discharge capacity (177 vs 124 mAh g?1 at 1 A g?1) after 1000 cycles.  相似文献   

19.
20.
The cathode materials in the Na‐ion battery system are always the key issue obstructing wider application because of their relatively low specific capacity and low energy density. A graphene oxide (GO) wrapped composite, Na2Fe2(SO4)3@C@GO, is fabricated via a simple freeze‐drying method. The as‐prepared material can deliver a 3.8 V platform with discharge capacity of 107.9 mAh g?1 at 0.1 C (1 C = 120 mA g?1) as well as offering capacity retention above 90% at a discharge rate of 0.2 C after 300 cycles. The well‐constructed carbon network provides fast electron transfer rates, and thus, higher power density also can be achieved (75.1 mAh g?1 at 10 C). The interface contribution of GO and Na2Fe2(SO4)3 is recognized and studied via density function theory calculation. The Na storage mechanism is also investigated through in situ synchrotron X‐ray diffraction, and pseudocapacitance contributions are also demonstrated. The diffusion coefficient of Na+ ions is around 10?12–10?10.8 cm2 s?1 during cycling. The higher working voltage of this composite is mainly ascribed to the larger electronegativity of the element S. The research indicates that this well‐constructed composite would be a competitive candidate as a cathode material for Na‐ion batteries.  相似文献   

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