首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 281 毫秒
1.
The application of lithium (Li) metal anodes in Li metal batteries has been hindered by growth of Li dendrites, which lead to short cycling life. Here a Li‐ion‐affinity leaky film as a protection layer is reported to promote a dendrite‐free Li metal anode. The leaky film induces electrokinetic phenomena to enhance Li‐ion transport, leading to a reduced Li‐ion concentration polarization and homogeneous Li‐ion distribution. As a result, the dendrite‐free Li metal anode during Li plating/stripping is demonstrated even at an extremely high deposition capacity (6 mAh cm?2) and current density (40 mA cm?2) with improved Coulombic efficiencies. A full cell battery with the leaky‐film protected Li metal as the anode and high‐areal‐capacity LiNi0.8Co0.1Mn0.1O2 (NCM‐811) (≈4.2 mAh cm?2) or LiFePO4 (≈3.8 mAh cm?2) as the cathode shows improved cycling stability and capacity retention, even at lean electrolyte conditions.  相似文献   

2.
An innovative and environmentally friendly battery chemistry is proposed for high power applications. A carbon‐coated ZnFe2O4 nanoparticle‐based anode and a LiFePO4‐multiwalled carbon nanotube‐based cathode, both aqueous processed with Na‐carboxymethyl cellulose, are combined, for the first time, in a Li‐ion full cell with exceptional electrochemical performance. Such novel battery shows remarkable rate capabilities, delivering 50% of its nominal capacity at currents corresponding to ≈20C (with respect to the limiting cathode). Furthermore, the pre‐lithiation of the negative electrode offers the possibility of tuning the cell potential and, therefore, achieving remarkable gravimetric energy and power density values of 202 Wh kg?1 and 3.72 W kg?1, respectively, in addition to grant a lithium reservoir. The high reversibility of the system enables sustaining more than 10 000 cycles at elevated C‐rates (≈10C with respect to the LiFePO4 cathode), while retaining up to 85% of its initial capacity.  相似文献   

3.
Na‐based batteries have long been regarded as an inexpensive, sustainable candidate for large‐scale stationary energy storage applications. Unfortunately, the market penetration of conventional Na‐NiCl2 batteries is approaching its limit for several reasons, including limited rate capability and high Ni cost. Herein, a Na‐FeCl2 battery operating at 190 °C is reported that allows a capacity output of 116 mAh g?1 at an extremely high current density of 33.3 mA cm?2 (≈0.6C). The superior rate performance is rooted in the intrinsically fast kinetics of the Fe/Fe2+ redox reaction. Furthermore, it is demonstrated that a small amount of Ni additive (10 mol%) effectively mitigates capacity fading of the Fe/NaCl cathode caused by Fe particle pulverization during long‐term cycling. The modified Fe/Ni cathode exhibits excellent cycling stability, maintaining a discharge energy density of over 295 Wh kg?1 for 200 cycles at 10 mA cm?2 (≈C/5).  相似文献   

4.
This study reports a Li–S battery cathode of high volumetric capacity enabled by novel micro‐ and mesostructuring. The cathode is based on monodisperse highly porous carbon nanospheres derived from a facile template‐ and surfactant‐free method. At the mesoscale, the nanospheres structure into interconnected close‐packed clusters of a few microns in extent, thus facilitating the fabrication of dense crack‐free high areal sulfur loading (5 mg cm?2) cathodes with high electrical conductivity and low cathode impedance. A combination of the nitrogen doping (5 wt%), high porosity (2.3 cm3 g?1), and surface area (2900 m2 g?1) at the microscale enables high sulfur immobilization and utilization. The cathode delivers among the best reported volumetric capacity to date, above typical Li‐ion areal capacity at 0.2 C over 200 cycles and low capacity fading of 0.1% per cycle at 0.5 C over 500 cycles. The compact cathode structure also ensures a low electrolyte requirement (6 µL mg?1), which aids a low overall cell weight, and further, among the best gravimetric capacities published to date as well.  相似文献   

5.
Herein, a two‐species redox reaction of Co(II)/Co(III) and Fe(II)/Fe(III) incorporated in cobalt hexacyanoferrate (CoFe(CN)6) is proposed as a breakthrough to achieve jointly high‐capacity and high‐voltage aqueous Zn‐ion battery. The Zn/CoFe(CN)6 battery provides a highly operational voltage plateau of 1.75 V (vs metallic Zn) and a high capacity of 173.4 mAh g?1 at current density of 0.3 A g?1, taking advantage of the two‐species redox reaction of Co(II)/Co(III) and Fe(II)/Fe(III) couples. Even under extremely fast charge/discharge rate of 6 A g?1, the battery delivers a sufficiently high discharge capacity of 109.5 mAh g?1 with its 3D opened structure framework. This is the highest capacity delivered among all the batteries using Prussian blue analogs (PBAs) cathode up to now. Furthermore, Zn/CoFe(CN)6 battery achieves an excellent cycling performance of 2200 cycles without any capacity decay at coulombic efficiency of nearly 100%. One further step, a sol–gel transition strategy for hydrogel electrolyte is developed to construct high‐performance flexible cable‐type battery. With the strategy, the active materials can adequately contact with electrolyte, resulting in improved electrochemical performance (≈18.73% capacity increase) and mechanical robustness of the solid‐state device. It is believed that this study optimizes electrodes by incorporating multi redox reaction species for high‐voltage and high‐capacity batteries.  相似文献   

6.
A challenge still remains to develop high‐performance and cost‐effective air electrode for Li‐O2 batteries with high capacity, enhanced rate capability and long cycle life (100 times or above) despite recent advances in this field. In this work, a new design of binder‐free air electrode composed of three‐dimensional (3D) graphene (G) and flower‐like δ‐MnO2 (3D‐G‐MnO2) has been proposed. In this design, graphene and δ‐MnO2 grow directly on the skeleton of Ni foam that inherits the interconnected 3D scaffold of Ni foam. Li‐O2 batteries with 3D‐G‐MnO2 electrode can yield a high discharge capacity of 3660 mAh g?1 at 0.083 mA cm?2. The battery can sustain 132 cycles at a capacity of 492 mAh g?1 (1000 mAh gcarbon ?1) with low overpotentials under a high current density of 0.333 mA cm?2. A high average energy density of 1350 Wh Kg?1 is maintained over 110 cycles at this high current density. The excellent catalytic activity of 3D‐G‐MnO2 makes it an attractive air electrode for high‐performance Li‐O2 batteries.  相似文献   

7.
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   

8.
Selenium (Se), due to its high electronic conductivity and high energy density, has recently attracted considerable interest as a cathode material for rechargeable Li/Na batteries. However, the poor cycling stability originating from the severe shuttle effect of polyselenides hinders their practical applications. Herein, highly stable Li/Na–Se batteries are developed using ultrathin (≈270 nm, loading of 0.09 mg cm?2) cetrimonium bromide (CTAB)/carbon nanotube (CNT)/Ti3C2Tx MXene hybrid modified polypropylene (PP) (CCNT/MXene/PP) separators. The hybrid separator can immobilize the polyselenides via enhanced Lewis acid–base interactions between CTAB/MXene and polyselenides, which is demonstrated by theoretical calculations and X‐ray photoelectron spectroscopy. The incorporation of CNT helps to improve the electrolyte infiltration and facilitate the ionic transport. In situ permeation experiments are conducted for the first time to visually study the behavior of polyselenides, revealing the prohibited shuttle effect and protected Li anode from corrosion with CCNT/MXene/PP separators. As a result, the Li–Se batteries with CCNT/MXene/PP separators deliver an outstanding cycling performance over 500 cycles at 1C with an extremely low capacity decay of 0.05% per cycle. Moreover, the hybrid separators also perform well in Na–Se batteries. This study develops a preferable separator–electrolyte interface and the concept can be applied in other conversion‐type battery systems.  相似文献   

9.
Lithium–sulfur (Li–S) batteries are deemed to be one of the most promising energy storage technologies because of their high energy density, low cost, and environmental benignancy. However, existing drawbacks including the shuttling of intermediate polysulfides, the insulating nature of sulfur, and the considerable volume change of sulfur cathode would otherwise result in the capacity fading and unstable cycling. To overcome these challenges, herein an in situ assembly route is presented to fabricate VS2/reduced graphene oxide nanosheets (G–VS2) as a sulfur host. Benefiting from the 2D conductive and polar VS2 interlayered within a graphene framework, the obtained G–VS2 hybrids can effectively suppress the polysulfide shuttling, facilitate the charge transport, and cushion the volume expansion throughout the synergistic effect of structural confinement and chemical anchoring. With these advantageous features, the obtained sulfur cathode (G–VS2/S) can deliver an outstanding rate capability (≈950 and 800 mAh g?1 at 1 and 2 C, respectively) and an impressive cycling stability at high rates (retaining ≈532 mAh g?1 after 300 cycles at 5 C). More significantly, it enables superior cycling performance of high‐sulfur‐loading cathodes (achieving an areal capacity of 5.1 mAh cm?2 at 0.2 C with a sulfur loading of 5 mg cm?2) even at high current densities.  相似文献   

10.
Herein, P′2‐type Na0.67[Ni0.1Fe0.1Mn0.8]O2 is introduced as a promising new cathode material for sodium‐ion batteries (SIBs) that exhibits remarkable structural stability during repetitive Na+ de/intercalation. The O? Ni? O? Mn? O? Fe? O bond in the octahedra of transition‐metal layers is used to suppress the elongation of the Mn? O bond and to improve the electrochemical activity, leading to the highly reversible Na storage mechanism. A high discharge capacity of ≈220 mAh g?1 (≈605 Wh kg?1) is delivered at 0.05 C (13 mAg?1) with a high reversible capacity of ≈140 mAh g?1 at 3 C and excellent capacity retention of 80% over 200 cycles. This performance is associated with the reversible P′2–OP4 phase transition and small volume change upon charge and discharge (≈3%). The nature of the sodium storage mechanism in a full cell paired with a hard carbon anode reveals an unexpectedly high energy density of ≈542 Wh kg?1 at 0.2 C and good capacity retention of ≈81% for 500 cycles at 1 C (260 mAg?1).  相似文献   

11.
Li metal anodes are going through a great revival but they still encounter grand challenges. One often neglected issue is that most reported Li metal anodes are only cyclable under relatively low current density (<5 mA cm?2) and small areal capacity (<5 mAh cm?2), which essentially limits their high‐power applications and results in ineffective Li utilization (<1%). Herein, it is reported that surface alloyed Li metal anodes can enable reversible cycling with ultrafast rate and ultralarge areal capacity. Low‐cost Si wafers are used and are chemically etched down to 20–30 µm membranes. Simply laminating a Si membrane onto Li foil results in the formation of LixSi alloy film fused onto Li metal with mechanical robustness and high Li‐ion conductivity. Symmetric cell measurements show that the surface alloyed Li anode has excellent cycling stability, even under high current density up to 25 mA cm?2 and unprecedented areal capacity up to 100 mAh cm?2. Furthermore, the surface alloyed Li anode is paired with amorphous MoS3 cathode and achieves remarkable full‐cell performance.  相似文献   

12.
A rechargeable, stretchable battery composed of a liquid metal alloy (eutectic gallium‐indium; EGaIn) anode, a carbon paste, and MnO2 slurry cathode, an alkaline electrolytic hydrogel, and a soft elastomeric package is presented. The battery can stably cycle within a voltage range of 1.40–1.86 V at 1 mA cm?2 while being subject to 100% tensile strain. This is accomplished through a mechanism that involves reversible stripping and plating of gallium along with MnO2 chemical conversion. Moreover, a technique to increase the contact area between the EGaIn anode and hydrogel interface using CaCl2 additives, which reduces polarization and therefore reduces the effective current density, leading to higher discharge plateaus and lower charge plateaus. Relative to previous attempts at energy storage with liquid metal, the EGaIn‐MnO2 battery presented here shows an exceptional areal specific capacity (≈3.8 mAh cm?2) and robust, stable rechargeability over >100 charging cycles. The battery is also stable under bending, with negligible change in electrochemical properties when bent to a 2 mm radius of curvature. Batteries embedded within a wearable elastomeric sleeve can power a blue light‐emitting diode and strain‐sensing circuit. These demonstrations suggest that stretchable EGaIn‐MnO2 batteries are feasible for applications in wearable energy‐storage electronics.  相似文献   

13.
A facile two‐step strategy is developed to design the large‐scale synthesis of hierarchical, unique porous architecture of ternary metal hydroxide nanowires grown on porous 3D Ni foam and subsequent effective sulfurization. The hierarchical Zn–Co–S nanowires (NWs) arrays are directly employed as an electrode for supercapacitors application. The as‐synthesized Zn–Co–S NWs deliver an ultrahigh areal capacity of 0.9 mA h cm?2 (specific capacity of 366.7 mA h g?1) at a current density of 3 mA cm?2, with an exceptional rate capability (≈227.6 mA h g?1 at a very high current density of 40 mA cm?2) and outstanding cycling stability (≈93.2% of capacity retention after 10 000 cycles). Most significantly, the assembled Zn–Co–S NWs//Fe2O3@reduced graphene oxide asymmetric supercapacitors with a wide operating potential window of ≈1.6 V yield an ultrahigh volumetric capacity of ≈1.98 mA h cm?3 at a current density of 3 mA cm?2, excellent energy density of ≈81.6 W h kg?1 at a power density of ≈559.2 W kg?1, and exceptional cycling performance (≈92.1% of capacity retention after 10 000 cycles). This general strategy provides an alternative to design the other ternary metal sulfides, making it facile, free‐standing, binder‐free, and cost‐effective ternary metal sulfide‐based electrodes for large‐scale applications in modern electronics.  相似文献   

14.
Rechargeable sodium–iodine batteries represent a promising scalable electrochemical energy storage alternative as sodium and iodine are both low cost and widely abundant elements. Here, the authors demonstrate a rechargeable sodium–iodine battery that employs free‐standing iodine quantum dots (IQDs) decorated reduced graphene oxide (IQDs@RGO) as the cathode. Consistent with the density functional theory the authors find the Na+ ions to intercalate into the I unit cell forming stable NaI, and the battery exhibits high capacity, outstanding cycle stability (with a reversible specific capacity of 141 mA h g?1 after 500 cycles at current density of 100 mA g?1), and high rate performance (170, 146, 127, 112, and 95 mA h g?1 at current densities of 100, 200, 400, 600, and 1000 mA g?1, respectively). The reversible reactions, I2/I3 ? and I3 ?/I? redox couples on insertion of Na+ ions, are confirmed via in situ Raman spectroscopy. Notably, even after 500 cycles the morphology and structure of the IQDs exhibit no noticeable change implying their use as a stable cathode material for sodium–iodine batteries. Moreover, the IQDs based flexible full‐cells also exhibit high capacity and long cycle life (the capacity with 123 mA h g?1 at current density of 100 mA g?1 after 100 cycles).  相似文献   

15.
All solid‐state sodium batteries (ASSBs) have attracted considerable attention due to their enhanced safety, long lifespan, and high energy density. However, several challenges have plagued the development of ASSBs, especially the relatively low ionic conductivity of solid‐state electrolytes (SSEs), large interfacial resistance, and low stability/compatibility between SSEs and electrodes. Here, a high‐performance all solid‐state sodium battery (NVP@C|PEGDMA‐NaFSI‐SPE|Na) is designed by employing carbon coated Na3V2(PO4)3 composite nanosheets (NVP@C) as the cathode, solvent‐free solid polymer electrolyte (PEGDMA‐NaFSI‐SPE) as the electrolyte and metallic sodium as the anode. The integrated electrolyte and cathode system prepared by the in situ polymerization process exhibits high ionic conductivity (≈10?4 S cm?1 at room temperature) and an outstanding electrolyte/electrode interface. Benefiting from these merits, the soft‐pack ASSB (NVP@C|PEGDMA‐NaFSI‐SPE|Na) delivers excellent cycling life over 740 cycles (capacity decay of only 0.007% per cycle) and maintains 95% of the initial reversible capacity with almost no self‐discharge even after resting for 3 months. Moreover, the bendable ASSB exhibits a high capacity of 106 mAh g?1 (corresponds to energy density of ≈355 Wh kg?1) at 0.5 C despite undergoing repeated bending for 535 cycles. This work offers a new strategy to fabricate high‐performance flexible ASSBs with a long lifespan and excellent flexibility.  相似文献   

16.
The design and fabrication of high‐performance all‐plastic batteries is essentially important to achieve future flexible electronics. A major challenge in this field is the lack of stable and reliable soft organic electrodes with satisfactory performance. Here, a novel all‐plastic‐electrode based Li‐ion battery with a single flexible bi‐functional ladderized heterocyclic poly(quinone), (C6O2S2)n, as both cathode and anode is demonstrated. Benefiting from its unique ladder‐like quinone and dithioether structure, the as‐prepared polymer cathode shows a high energy density of 624 Wh kg?1 (vs lithium anode) and a stable battery life of 1000 cycles. Moreover, the as‐fabricated symmetric full‐battery delivers a large capacity of 249 mAh g?1 (at 20 mA g?1), a good capacity retention of 119 mAh g?1 after 250 cycles (at 1.0 A g?1) and a noteworthy energy density up to 276 Wh kg?1. The superior performance of poly(2,3‐dithiino‐1,4‐benzoquinone)‐based electrode rivals most of the state‐of‐the‐art demonstrations on organic‐based metal‐ion shuttling batteries. The study provides an effective strategy to develop stable bi‐functional electrode materials toward the next‐generation of high performance all‐plastic batteries.  相似文献   

17.
Energy density (energy per volume) is a key consideration for portable, automotive, and stationary battery applications. Selenium (Se) lithium and sodium metal cathodes are created that are monolithic and free‐standing, and with record Se loading of 70 wt%. The carbon host is derived from nanocellulose, an abundant and sustainable forestry product. The composite is extremely dense (2.37 g cm?3), enabling theoretical volumetric capacity of 1120 mA h cm?3. Such architecture is fully distinct from previous Se–carbon nano‐ or micropowders, intrinsically offering up to 2× higher energy density. For Li storage, the cathode delivers reversible capacity of 1028 mA h cm?3 (620 mA h g?1) and 82% retention over 300 cycles. For Na storage, 848 mA h cm?3 (511 mA h g?1) is obtained with 98% retention after 150 cycles. The electrodes yield superb volumetric energy densities, being 1727 W h L?1 for Li–Se and 980 W h L?1 for Na–Se normalized by total composite mass and volume. Despite the low surface area, over 60% capacity is maintained as the current density is increased from 0.1 to 2 C (30 min charge) with Li or Na. Remarkably, the electrochemical kinetics with Li and Na are comparable, including the transition from interfacial to diffusional control.  相似文献   

18.
The high‐polarity β‐phase poly(vinylidene difluoride) (β‐PVDF), which has all trans conformation with F and H atoms located on the opposite sides of the polymer backbone, is demonstrated to be a promising artificial solid‐electrolyte interphase coating on both Cu and Li metal anodes for dendrite‐free Li deposition/stripping and enhanced cycling performance. A thin (≈4 µm) β‐PVDF coating on Cu enables uniform Li deposition/stripping at high current densities up to 5 mA cm?2, Li‐plating capacity loadings of up to 4 mAh cm?2, and excellent cycling stability over hundreds of cycles under practical conditions (1 mA cm?2 with 2 mAh cm?2). Full cells containing an LiFePO4 cathode and an anode of either β‐PVDF coated Cu or Li also exhibit excellent cycling stability. The profound effects of the high‐polarity PVDF coating on dendrite suppression are attributed to the electronegative F‐rich interface that favors layer‐by‐layer Li deposition. This study offers a new strategy for the development of dendrite‐free metal anode technology.  相似文献   

19.
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   

20.
Rational structure design of the current collector along with further engineering of the solid‐electrolyte interphases (SEI) layer is one of the most promising strategies to achieve uniform Li deposition and inhibit uncontrolled growth of Li dendrites. Here, a Li2S layer as an artificial SEI with high compositional uniformity and high lithium ion conductivity is in situ generated on the surface of the 3D porous Cu current collector to regulate homogeneous Li plating/stripping. Both simulations and experiments demonstrate that the Li2S protective layer can passivate the porous Cu skeleton and balance the transport rate of lithium ions and electrons, thereby alleviating the agglomerated Li deposition at the top of the electrode or at the defect area of the SEI layer. As a result, the modified current collector exhibits long‐term cycling of 500 cycles at 1 mA cm?2 and stable electrodeposition capabilities of 4 mAh cm?2 at an ultrahigh current density of 4 mA cm?2. Furthermore, full batteries (LiFePO4 as cathode) paired with this designed 3D anode with only ≈200% extra lithium show superior stability and rate performance than the batteries paired with lithium foil (≈3000% extra lithium). These explorations provide new strategies for developing high‐performance Li metal anodes.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号