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1.
The large‐scale implementation of lithium metal batteries (LMBs) has long been plagued by the uncontrollable Li deposition triggered safety issues. Herein, a lithiophilic three‐dimensional Li anode scaffold, which is prepared by molten Li infusion aided by confined growth of low‐cost Zn clusters, is rationally constructed for high‐performance LMBs. Owing to the synergy of the carbon host and the effective regulation from the Zn nanoclusters, the large volumetric change of Li metal is well mitigated and shows a smooth and dendrite‐free behavior. The Li anode scaffold can deliver much improved Coulombic efficiency, superior rate performance, and long cycle lifespan with much lower voltage polarization. Furthermore, the half cells of Li anode scaffold paired with LiFePO4/LiCoO2/sulfur can achieve a higher specific capacity and longer stable cycling life than those with conventional Li foil. The Li|LFP cells can achieve a stable cycling over 250 cycles at 1C with a higher capacity retention of ≈90.8%, and a higher initial discharge capacity of 924.6 mAh g?1 with a high capacity retention over 300 cycles can also be obtained in Li|S cells at 1C. This work demonstrates a cost‐effective and scalable strategy for stable Li metal anode toward next‐generation and high‐performance LMBs.  相似文献   

2.
Much attention is paid to metal lithium as a hopeful negative material for reversible batteries with a high specific capacity. Although applying 3D hosts can relieve the dendrite growth to some extent, gradient‐distributed lithium ion in 3D uniform hosts still induces uncontrolled lithium dendrites growth, especially at high lithium capacity and high current density. Herein, a 3D conductive carbon nanofiber framework with gradient‐distributed ZnO particles as nucleation seeds (G‐CNF) to regulate lithium deposition is proposed. Based on such a unique structure, the G‐CNF electrode exhibits a high average Coulombic efficiency (CE) of 98.1% for 700 cycles at 0.5 mA cm?2. Even at 5 mA cm?2, the G‐CNF electrode performs a stable cycling process and high CE of 96.0% for over 200 cycles. When the lithium‐deposited G‐CNF (G‐CNF‐Li) anode is applied in a full cell with a commercial LiFePO4 cathode, it exhibits a stable capacity of 115 mAh g?1 and high retention of 95.7% after 300 cycles. Through inducing the gradient‐distributed nucleation seeds to counter the existing Li‐ion concentration polarization, a uniform and stable lithium deposition process in the 3D host is achieved even under the condition of high current density.  相似文献   

3.
Metallic lithium (Li), considered as the ultimate anode, is expected to promise high‐energy rechargeable batteries. However, owing to the continuous Li consumption during the repeated Li plating/stripping cycling, excess amount of the Li metal anode is commonly utilized in lithium‐metal batteries (LMBs), leading to reduced energy density and increased cost. Here, an all‐solid‐state lithium‐metal battery (ASSLMB) based on a garnet‐oxide solid electrolyte with an ultralow negative/positive electrode capacity ratio (N/P ratio) is reported. Compared with the counterpart using a liquid electrolyte at the same low N/P ratios, ASSLMBs show longer cycling life, which is attributed to the higher Coulombic efficiency maintained during cycling. The effect of the species of the interface layer on the cycling performance of ASSLMBs with low N/P ratio is also studied. Importantly, it is demonstrated that the ASSLMB using a limited Li metal anode paired with a LiFePO4 cathode (5.9 N/P ratio) delivers a stable long‐term cycling performance at room temperature. Furthermore, it is revealed that enhanced specific energies for ASSLMBs with low N/P ratios can be further achieved by the use of a high‐voltage or high mass‐loading cathode. This study sheds light on the practical high‐energy all‐solid‐state batteries under the constrained condition of a limited Li metal anode.  相似文献   

4.
The viable Li metal anodes (LMAs) are still hampered by the safety concerns resulting from fast Li dendrite growth and huge volume expansion during cycling. Herein, carbon nanofiber matrix anchored with MgZnO nanoparticles (MgZnO/CNF) is developed as a flexible triple‐gradient host for long cycling LMAs. The superlithiophilic MgZnO nanoparticles significantly increase the wettability of CNF for fast and homogeneous infusion with molten Li. The in‐built potential and lithiophilic gradients constructed after an in situ lithiation of MgZnO and CNF enable nearly zero Li nucleation overpotential and homogeneous deposition of lithium at different scales. As such, the LMAs based on MgZnO/CNF achieve long cycling life and small overpotential even at a record‐high current density of 50 mA cm?2 and a high areal capacity of 10 mAh cm?2. A full cell paring with this designed LMA and LiFePO4 exhibits a capacity retention up to 82% after 600 cycles at a high rate of 5 C. A Li‐ion capacitor also shows an impressive capacity retention of 84% at 5 A g?1 after 10 000 cycles. Such a Li@MgZnO/CNF anode is a promising candidate for Li‐metal energy storage systems, especially working under ultrahigh current density.  相似文献   

5.
A novel spinel Co2VO4 is studied as the Li‐ion battery anode material and it is sandwiched with a 3D ultralight porous current collector (PCC) and amorphous carbon. Co2VO4 demonstrates the high capacity and excellent cyclability because of the mixed lithium storage mechanisms. The 3D composite structure requires no binders and replaces the conventional current collector (Cu foil) with a 3D ultralight porous metal scaffold, yielding the high electrode‐based capacity. Such a novel composite anode also enables the close adhesion of Co2VO4 to the PCC scaffold. The resulting monolithic electrode has the rapid electron pathway and stable mechanical properties, which lead to the excellent rate capabilities and cycling properties. At a current density of 1 A g?1, the PCC and carbon sandwiched Co2VO4 anode is able to deliver a stable reversible capacity of about 706.8 mAh g?1 after 1000 cycles. Generally, this study not only develops a new Co2VO4 anode with high capacity and good cyclability, but also demonstrates an alternative approach to improve the electrochemical properties of high capacity anode materials by using ultralight porous metallic current collector instead of heavy copper foil.  相似文献   

6.
Li metal is demonstrated as one of the most promising anode materials for high energy density batteries. However, uncontrollable Li dendrite growth and repeated growth of solid electrolyte interface during the charge/discharge process lead to safety issues and capacity decay, preventing its practical application. To address these issues, an effective strategy is to realize uniform Li nucleation. Here, a stable lithium–scaffold composite electrode (CC/CNT@Li) is designed by melting of lithium metal into 3D interconnected lithiophilic carbon nanotube (CNT) on a porous carbon cloth (CC). The 3D interconnected CNTs successfully change the lithiophobic CC into lithiophilic nature, reducing the polarization of the electrode, ensuring homogenous Li nucleation and continuous smooth Li plating. The CNTs on the surface of CC provide adequate Li nucleation sites and reduce the areal current density to avoid Li dendrite growth. The 3D porous structure of CC/CNT offers enough free room for buffering the huge volume change during Li plating/stripping. The CC/CNT@Li composite anode exhibits dendrite‐free morphology and superior cycling performances over 500 h with low voltage hysteresis of 18, 23, and 71 mV at the current density of 1, 2, and 5 mA cm?2, respectively.  相似文献   

7.
Despite the recent attention for Li metal anode (LMA) with high theoretical specific capacity of ≈ 3860 mA h g?1, it suffers from not enough practical energy densities and safety concerns originating from the excessive metal load, which is essential to compensate for the loss of Li sources resulting from their poor coulombic efficiencies (CEs). Therefore, the development of high‐performance LMA is needed to realize anode‐minimized Li metal batteries (LMBs). In this study, high‐performance LMAs are produced by introducing a hierarchically nanoporous assembly (HNA) composed of functionalized onion‐like graphitic carbon building blocks, several nanometers in diameter, as a catalytic scaffold for Li‐metal storage. The HNA‐based electrodes lead to a high Li ion concentration in the nanoporous structure, showing a high CE of ≈ 99.1%, high rate capability of 12 mA cm?2, and a stable cycling behavior of more than 750 cycles. In addition, anode‐minimized LMBs are achieved using a HNA that has limited Li content ( ≈ 0.13 mg cm?2), corresponding to 6.5% of the cathode material (commercial NCM622 ( ≈ 2 mg cm?2)). The LMBs demonstrate a feasible electrochemical performance with high energy and power densities of ≈ 510 Wh kgelectrode?1 and ≈ 2760 W kgelectrode?1, respectively, for more than 100 cycles.  相似文献   

8.
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   

9.
Uncontrolled ion transport and susceptible SEI films are the key factors that induce lithium dendrite growth, which hinders the development of lithium metal batteries (LMBs). Herein, a TpPa-2SO3H covalent organic framework (COF) nanosheet adhered cellulose nanofibers (CNF) on the polypropylene separator (COF@PP) is successfully designed as a battery separator to respond to the aforementioned issues. The COF@PP displays dual-functional characteristics with the aligned nanochannels and abundant functional groups of COFs, which can simultaneously modulate ion transport and SEI film components to build robust lithium metal anodes. The Li//COF@PP//Li symmetric cell exhibits stable cycling over 800 h with low ion diffusion activation energy and fast lithium ion transport kinetics, which effectively suppresses the dendrite growth and improves the stability of Li+ plating/stripping. Moreover, The LiFePO4//Li cells with COF@PP separator deliver a high discharge capacity of 109.6 mAh g−1 even at a high current density of 3 C. And it exhibits excellent cycle stability and high capacity retention due to the robust LiF-rich SEI film induced by COFs. This COFs-based dual-functional separator promotes the practical application of lithium metal batteries.  相似文献   

10.
Rechargeable lithium‐metal batteries (LMBs) are regarded as the “holy grail” of energy‐storage systems, but the electrolytes that are highly stable with both a lithium‐metal anode and high‐voltage cathodes still remain a great challenge. Here a novel “localized high‐concentration electrolyte” (HCE; 1.2 m lithium bis(fluorosulfonyl)imide in a mixture of dimethyl carbonate/bis(2,2,2‐trifluoroethyl) ether (1:2 by mol)) is reported that enables dendrite‐free cycling of lithium‐metal anodes with high Coulombic efficiency (99.5%) and excellent capacity retention (>80% after 700 cycles) of Li||LiNi1/3Mn1/3Co1/3O2 batteries. Unlike the HCEs reported before, the electrolyte reported in this work exhibits low concentration, low cost, low viscosity, improved conductivity, and good wettability that make LMBs closer to practical applications. The fundamental concept of “localized HCEs” developed in this work can also be applied to other battery systems, sensors, supercapacitors, and other electrochemical systems.  相似文献   

11.
Li anodes have been rapidly developed in recent years owing to the rising demand for higher‐energy‐density batteries. However, the safety issues induced by dendrites hinder the practical applications of Li anodes. Here, Li metal anodes stabilized by regulating lithium plating/stripping in vertically aligned microchannels are reported. The current density distribution and morphology evolution of the Li deposits on porous Cu current collectors are systematically analyzed. Based on simulations in COMSOL Multiphysics, the tip effect leads to preferential deposition on the microchannel walls, thus taking full advantage of the lightening rod theory of classical electromagnetism for restraining growth of Li dendrites. The Li anode with a porous Cu current collector achieves an enhanced cycle stability and a higher average Coulombic efficiency of 98.5% within 200 cycles. In addition, the resultant LiFePO4/Li full battery demonstrates excellent rate capability and stable cycling performance, thus demonstrating promise as a current collector for high‐energy‐density, safe rechargeable Li batteries.  相似文献   

12.
Metallic lithium is the most competitive anode material for next-generation lithium (Li)-ion batteries. However, one of its major issues is Li dendrite growth and detachment, which not only causes safety issues, but also continuously consumes electrolyte and Li, leading to low coulombic efficiency (CE) and short cycle life for Li metal batteries. Herein, the Li dendrite growth of metallic lithium anode is suppressed by forming a lithium fluoride (LiF)-enriched solid electrolyte interphase (SEI) through the lithiation of surface-fluorinated mesocarbon microbeads (MCMB-F) anodes. The robust LiF-enriched SEI with high interfacial energy to Li metal effectively promotes planar growth of Li metal on the Li surface and meanwhile prevents its vertical penetration into the LiF-enriched SEI from forming Li dendrites. At a discharge capacity of 1.2 mAh cm−2, a high CE of >99.2% for Li plating/stripping in FEC-based electrolyte is achieved within 25 cycles. Coupling the pre-lithiated MCMB-F (Li@MCMB-F) anode with a commercial LiFePO4 cathode at the positive/negative (P/N) capacity ratio of 1:1, the LiFePO4//Li@MCMB-F cells can be charged/discharged at a high areal capacity of 2.4 mAh cm−2 for 110 times at a negligible capacity decay of 0.01% per cycle.  相似文献   

13.
Lithium (sodium)‐metal batteries are the most promising batteries for next‐generation electrical energy storage due to their high volumetric energy density and gravimetric energy density. However, their applications have been prevented by uncontrollable dendrite growth and large volume expansion during the stripping/plating process. To address this issue, the key strategy is to realize uniform lithium (sodium) deposition during the stripping/plating process. Herein, a thin lithiophilic layer consisting of RuO2 particles anchored on brush‐like 3D carbon cloth (RuO2@CC) is prepared by a simple solution‐based method. After infusion of Li, the RuO2@CC transfers to Li‐Ru@CC. Ru nanoparticles not only play a role in leading Li+ (Na+) to plate on the 3D carbon framework, but also lower local current density because of the good electrical conductivity. Furthermore, density functional theory calculations demonstrate that Ru metal, the reaction product of alkali metal and Ru, can lead Li+ to plate evenly around carbon fiber owing to the strong binding energy with Li+. The Li‐Ru@CC anode shows ultralong cycle life (1500 h at 5 mA cm?2). The full cell of Li‐Ru@CC|LiFePO4 exhibits lower polarization (90% capacity retention after 650 cycles). In addition, sodium metal batteries based on Na‐Ru@CC anodes can achieve similar improvement.  相似文献   

14.
All‐solid‐state batteries (ASSBs) with ceramic‐based solid‐state electrolytes (SSEs) enable high safety that is inaccessible with conventional lithium‐ion batteries. Lithium metal, the ultimate anode with the highest specific capacity, also becomes available with nonflammable SSEs in ASSBs, which offers promising energy density. The rapid development of ASSBs, however, is significantly hampered by the large interfacial resistance as a matched lithium/ceramic interface that is not easy to pursue. Here, a lithium–graphite (Li–C) composite anode is fabricated, which shows a dramatic modification in wettability with garnet SSE. An intimate Li–C/garnet interface is obtained by casting Li–C composite onto garnet‐type SSE, delivering an interfacial resistance as low as 11 Ω cm2. As a comparison, pure Li/garnet interface gives a large resistance of 381 Ω cm2. Such improvement can be ascribed to the experiment‐measured increased viscosity of Li–C composite and simulation‐verified limited interfacial reaction. The Li–C/garnet/Li–C symmetric cell exhibits stable plating/striping performance with small voltage hysteresis and endures a critical current density up to 1.0 mA cm?2. The full cell paired with LiFePO4 shows stable cycle performance, comparable to the cell with liquid electrolyte. The present work demonstrates a promising strategy to develop ceramic‐compatible lithium metal‐based anodes and hence low‐impedance ASSBs.  相似文献   

15.
Thanks to its high specific capacity and low electrochemical potential, lithium metal is an ideal anode for next-generation high-energy batteries. However, the unstable heterogeneous surface of lithium gives rise to safety and efficiency concerns that prevent it from being utilized in practical applications. In this work, the formation of a closed-host bi-layer solid electrolyte interphase (SEI) improves the stability of lithium metal anode. This is successfully realized by forming an interconnected porous LiF-rich artificial SEI in contact with Li metal, and a dense, stable in-situ formed upper layer SEI. The porous layer increases the number of Li/LiF interfaces, which reduces local volume fluctuations and improves Li+ diffusion along these interfaces. Additionally, the tortuous porous structure guides uniform Li+ flux distribution and mechanically suppresses dendrite propagation. The dense upper layer of the SEI accomplishes a closed-host design, preventing continuous consumption of active materials. The duality of a dense top layer with porous bottom layer led to extended cycle life and improved rate performance, evidenced with symmetric cell testing, as well as full cell testing paired with sulfur and LiFePO4 (LFP) cathodes. This work is a good example of a rational design of the SEI, based on comprehensive consideration of various critical factors to improve Li-metal anode stability, and highlights a new pathway to improve cycling and rate performances of Li metal batteries.  相似文献   

16.
Suppressing the dendrite formation and managing the volume change of lithium (Li) metal anode have been global challenges in the lithium batteries community. Herein, a duplex copper (Cu) foil with an ant‐nest‐like network and a dense substrate is reported for an ultrastable Li metal anode. The duplex Cu is fabricated by sulfurization of thick Cu foil with a subsequent skeleton self‐welding procedure. Uniform Li deposition is achieved by the 3D interconnected architecture and lithiophilic surface of self‐welded Cu skeleton. The sufficient space in the porous layer enables a large areal capacity for Li and significantly improves the electrode–electrolyte interface. Simulations reveal that the structure allows proper electric field penetration into the connected tunnels. The assembled Li anodes exhibit high coulombic efficiency (97.3% over 300 cycles) and long lifespan (>880 h) at a current density of 1 mA cm?2 with a capacity of 1 mAh cm?2. Stable and deep cycling can be maintained up to 50 times at a high capacity of 10 mAh cm?2.  相似文献   

17.
Lithium metal is considered as the most promising anode material due to its high theoretical specific capacity and the low electrochemical reduction potential. However, severe dendrite problems have to be addressed for fabricating stable and rechargeable batteries (e.g., lithium–iodine batteries). To fabricate a high‐performance lithium–iodine (Li–I2) battery, a 3D stable lithium metal anode is prepared by loading of molten lithium on carbon cloth doped with nitrogen and phosphorous. Experimental observations and theoretical calculation reveal that the N,P codoping greatly improves the lithiophilicity of the carbon cloth, which not only enables the uniform loading of molten lithium but also facilitates reversible lithium stripping and plating. Dendrites formation can thus be significantly suppressed at a 3D lithium electrode, leading to stable voltage profiles over 600 h at a current density of 3 mA cm?2. A fuel cell with such an electrode and a lithium–iodine cathode shows impressive long‐term stability with a capacity retention of around 100% over 4000 cycles and enhanced high‐rate capability. These results demonstrate the promising applications of 3D stable lithium metal anodes in next‐generation rechargeable batteries.  相似文献   

18.
Lithium‐metal batteries can fulfill the ever‐growing demand of the high‐energy‐density requirement of electronics and electric vehicles. However, lithium‐metal anodes have many challenges, especially their inhomogeneous dendritic formation and infinite dimensional change during cycling. 3D scaffold design can mitigate electrode thickness fluctuation and regulate the deposition morphology. However, in an insulating or ion‐conducting matrix, Li as the exclusive electron conductor can become disconnected, whereas in an electron‐conducting matrix, the rate performance is restrained by the sluggish Li+ diffusion. Herein, the advantages of both ion‐ and electron‐conducting paths are integrated into a mixed scaffold. In the mixed ion‐ and electron‐conducting network, the charge diffusion and distribution are facilitated leading to significantly improved electrochemical performance. By incorporating Li6.4La3Zr2Al0.2O12 nanoparticles into 3D carbon nanofibers scaffold, the Li metal anodes can deliver areal capacity of 16 mAh cm?2, volumetric capacity of 1600 mAh cm?3, and remain stable over 1000 h under current density of 5 mA cm?2. The volumetric and areal capacities as well as the rate capability are among the highest values reported. It is anticipated that the 3D mixed scaffold could be combined with further electrolytes and cathodes to develop high‐performance energy systems.  相似文献   

19.
Implementing the utilization of lithium metal in actual processing and application conditions is essential for next-generation high-energy batteries at a practical level. However, the air/water instability of the high-reactive Li metal remains unsolved. Here, a water-stable Li metal anode with ultrahigh-rate capability enabled by a rationally designed architecture is reported. A hydrophobic graphene framework, consists of an array of vertically aligned sheets and a roof of sloping-aligned sheets, is utilized to fully host lithium metal. As a result, it is first demonstrated that the composite Li metal anode can run stably even after it directly contacts with water. In addition, both the arrays and the roof in the framework are directional graphene microsheets that can provide fast charge transport kinetics in the anode without tortuosity. Therefore, the anode can operate at an extremely high current density of 50 mA cm−2 with long-term cycling stability. Importantly, the composite Li anodes in Li||LiFePO4 and Li||NCM-811 cells also show much improved performances than Li metal foil under crucial conditions of lean electrolyte and low negative/positive capacity ratio. This design provides a significant stride in the safety toward the practicability of low air/water tolerance materials.  相似文献   

20.
Rechargeable lithium (Li) metal batteries (LMBs) with ultrahigh-nickel (Ni) layered oxide cathodes offer a great opportunity for applications in electrical vehicles. However, increasing Ni content inherently arouses a tradeoff between specific capacity and electrochemical cyclability due to the aggressive side reactions with electrolyte contributed by the highly reactive Ni species. Here, a protective and stable cathode/electrolyte interphase featuring enriched and evenly-distributed LiF is in situ formed on ultrahigh-Ni cathode LiNi0.94Co0.06O2 (NC) with an advanced ether-based localized high-concentration electrolyte (LHCE), which concurrently shows good compatibility with Li metal anode. Subsequently, the NC cathode can deliver high capacity retentions of 81.4% after 500 cycles at 25 °C and 91.6% after 100 cycles at 60 °C in the voltage range of 2.8–4.4 V in Li||NC cells at 1C cycling rate (1.5 mA cm−2). Meanwhile, the conductive electrode/electrolyte interphases formed in LHCE enable a high reversible capacity of about 209 mAh g−1 at 3C charging rate. This work provides an effective approach and important insight from the perspective of in situ ultrahigh-Ni cathode/electrolyte interphase protection for high energy–density, long-lasting LMBs.  相似文献   

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