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1.
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   

2.
Metallic lithium (Li) is a promising anode material for next‐generation rechargeable batteries. However, the dendrite growth of Li and repeated formation of solid electrolyte interface during Li plating and stripping result in low Coulombic efficiency, internal short circuits, and capacity decay, hampering its practical application. In the development of stable Li metal anode, the current collector is recognized as a critical component to regulate Li plating. In this work, a lithiophilic Cu‐CuO‐Ni hybrid structure is synthesized as a current collector for Li metal anodes. The low overpotential of CuO for Li nucleation and the uniform Li+ ion flux induced by the formation of Cu nanowire arrays enable effective suppression of the growth of Li dendrites. Moreover, the surface Cu layer can act as a protective layer to enhance structural durability of the hybrid structure in long‐term running. As a result, the Cu‐CuO‐Ni hybrid structure achieves a Coulombic efficiency above 95% for more than 250 cycles at a current density of 1 mA cm?2 and 580 h (290 cycles) stable repeated Li plating and stripping in a symmetric cell.  相似文献   

3.
For its high theoretical capacity and low redox potential, Li metal is considered to be one of the most promising anode materials for next‐generation batteries. However, practical application of a Li‐metal anode is impeded by Li dendrites, which are generated during the cycling of Li plating/stripping, leading to safety issues. Researchers attempt to solve this problem by spatially confining the Li plating. Yet, the effective directing of Li deposition into the confined space is challenging. Here, an interlayer is constructed between a graphitic carbon nitrite layer (g‐C3N4) and carbon cloth (CC), enabling site‐directed dendrite‐free Li plating. The g‐C3N4/CC as an anode scaffold enables extraordinary cycling stability for over 1500 h with a small overpotential of ≈80 mV at 2 mA cm?2. Furthermore, prominent battery performance is also demonstrated in a full cell (Li/g‐C3N4/CC as anode and LiCoO2 as cathode) with high Coulombic efficiency of 99.4% over 300 cycles.  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.
Considerable efforts are devoted to relieve the critical lithium dendritic and volume change problems in the lithium metal anode. Constructing uniform Li+ distribution and lithium “host” are shown to be the most promising strategies to drive practical lithium metal anode development. Herein, a uniform Li nucleation/growth behavior in a confined nanospace is verified by constructing vertical graphene on a 3D commercial copper mesh. The difference of solid‐electrolyte interphase (SEI) composition and lithium growth behavior in the confined nanospace is further demonstrated by in‐depth X‐ray photoelectron spectrometer (XPS) and line‐scan energy dispersive X‐ray spectroscopic (EDS) methods. As a result, a high Columbic efficiency of 97% beyond 250 cycles at a current density of 2 mA cm?2 and a prolonged lifespan of symmetrical cell (500 cycles at 5 mA cm?2) can be easily achieved. More meaningfully, the solid‐state lithium metal cell paired with the composite lithium anode and LiNi0.5Co0.2Mn0.3O2 (NCM) as the cathode also demonstrate reduced polarization and extended cycle. The present confined nanospace–derived hybrid anode can further promote the development of future all solid‐state lithium metal batteries.  相似文献   

6.
Polymer‐based electrolytes have attracted ever‐increasing attention for all‐solid‐state lithium (Li) metal batteries due to their ionic conductivity, flexibility, and easy assembling into batteries, and are expected to overcome safety issues by replacing flammable liquid electrolytes. However, it is still a critical challenge to effectively block Li dendrite growth and improve the long‐term cycling stability of all‐solid‐state batteries with polymer electrolytes. Here, the interface between novel poly(vinylidene difluoride) (PVDF)‐based solid electrolytes and the Li anode is explored via systematical experiments in combination with first‐principles calculations, and it is found that an in situ formed nanoscale interface layer with a stable and uniform mosaic structure can suppress Li dendrite growth. Unlike the typical short‐circuiting that often occurs in most studied poly(ethylene oxide) systems, this interface layer in the PVDF‐based system causes an open‐circuiting feature at high current density and thus avoids the risk of over‐current. The effective self‐suppression of the Li dendrite observed in the PVDF–LiN(SO2F)2 (LiFSI) system enables over 2000 h cycling of repeated Li plating–stripping at 0.1 mA cm?2 and excellent cycling performance in an all‐solid‐state LiCoO2||Li cell with almost no capacity fade after 200 cycles at 0.15 mA cm?2 at 25 °C. These findings will promote the development of safe all‐solid‐state Li metal batteries.  相似文献   

7.
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   

8.
Lithium metal is an attractive anode material for rechargeable batteries because of its high theoretical specific capacity of 3860 mA h g?1 and the lowest negative electrochemical potential of ?3.040 V versus standard hydrogen electrode. Despite extensive research efforts on tackling the safety concern raised by Li dendrites, inhibited Li dendrite growth is accompanied with decreased areal capacity and Li utilization, which are still lower than expectation for practical use. A scaffold made of covalently connected graphite microtubes is reported, which provides a firm and conductive framework with moderate specific surface area to accommodate Li metal for anodes of Li batteries. The anode presents an areal capacity of 10 mA h cm?2 (practical gravimetric capacity of 913 mA h g?1) at a current density of 10 mA cm?2, with Li utilization of 91%, Coulombic efficiencies of ≈97%, and long lifespan of up to 3000 h. The analysis of structure evolution during charge/discharge shows inhibited lithium dendrite growth and a reversible electrode volume change of ≈9%. It is suggested that an optimized microstructure with moderate electrode/electrolyte interface area is critical to accommodate volume change and inhibit the risks of irreversible Li consumption by side reactions and Li dendrite growth for high‐performance Li‐metal anodes.  相似文献   

9.
Lithium (Li) metal anodes have attracted much interest recently for high‐energy battery applications. However, low coulombic efficiency, infinite volume change, and severe dendrite formation limit their reliable implementation over a wide range. Here, an outstanding stability for a Li metal anode is revealed by designing a highly porous and hollow Li foam. This unique structure is capable of tackling many Li metal problems simultaneously: first, it assures uniform electrolyte distribution over the inner and outer electrode's surface; second, it reduces the local current density by providing a larger electroactive surface area; third, it can accommodate volume expansion and dissipate heat efficiently. Moreover, the structure shows superior stability compared to fully Li covered foam with low porosity, and bulky Li foil electrode counterparts. This Li foam exhibits small overpotential (≈25 mV at 4 mA cm?2) and high cycling stability for 160 cycles at 4 mA cm?2. Furthermore, when assembled, the porous Li metal as the anode with LiFePO4 as the cathode for a full cell, the battery has a high‐rate performance of 138 mAh g?1 at 0.2 C. The beneficial structure of the Li hollow foam is further studied through density functional theory simulations, which confirms that the porous structure has better charge mobility and more uniform Li deposition.  相似文献   

10.
Although with an extremely high theoretical capacity (3860 mA h g?1), the lithium (Li) metal anodes reported so far typically possess capacities of ≤5 mA h cm?2 and cyclable at currents of ≤5 mA cm?2. In this work, a hierarchal carbon scaffold is designed with the self‐growth of carbon nanotubes (CNTs) in nickel‐decorated melamine sponges via thermal annealing. It is found that the nitrogen‐doped carbon obtained from the melamine sponge, coupled with CNTs, provides an overall strong yet internally flexible host which enables an areal capacity of up to 15 mA h cm?2 cyclable at a charging/discharging current of 15 mA cm?2 as Li metal anodes. Characterizations show that the highly conductive yet uniformly distributed CNTs effectively suppress the local current density, leading to more uniform Li nucleation in Li plating. The flexible CNTs in the stiff scaffold enhance the tolerance to the stress caused by the intrinsic volume variation in Li plating/striping, resulting in the stable cycling performance at high currents. This study provides a potentially scalable and cost‐effective strategy for preparation of high‐performance Li‐metal anodes.  相似文献   

11.
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   

12.
The application and development of lithium metal battery are severely restricted by the uncontrolled growth of lithium dendrite and poor cycle stability. Uniform lithium deposition is the core to solve these problems, but it is difficult to be achieved on commercial Cu collectors. In this work, a simple and commercially viable strategy is utilized for large‐scale preparation of a modified planar Cu collector with lithiophilic Ag nanoparticles by a simple substitution reaction. As a result, the Li metal shows a cobblestone‐like morphology with similar size and uniform distribution rather than Li dendrites. Interestingly, a high‐quality solid electrolyte interphase layer in egg shell‐like morphology with fast ion diffusion channels is formed on the interface of the collector, exhibiting good stability with long‐term cycles. Moreover, at the current density of 1 mA cm?2 for 1 mAh cm?2, the Ag modified planar Cu collector shows an ultralow nucleation overpotential (close to 0 mV) and a stable coulombic efficiency of 98.54% for more than 600 cycles as well as long lifespan beyond 900 h in a Li|Cu‐Ag@Li cell, indicating the ability of this method to realize stable Li metal batteries. Finally, full cells paired with LiNi0.8Co0.1Mn0.1O2 show superior rate performance and stability compared with those paired with Li foil.  相似文献   

13.
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   

14.
There has been a renewed interest in using lithium (Li) metal as an anode material for rechargeable batteries owing to its high theoretical capacity of 3860 mA h g?1. Despite extensive research, modifications to effectively inhibit Li dendrite growth still result in decreased Li loading and Li utilization. As a result, real capacities are often lower than values expected, if the total mass of the electrode is taken into consideration. Herein, a lightweight yet mechanically robust carbon nanotube (CNT) paper is demonstrated as a freestanding framework to accommodate Li metal with a Li mass fraction of 80.7 wt%. The highly conductive network made of sp2‐hybridized carbon effectively inhibits formation of Li dendrites and affords a favorable coulombic efficiency of >97.5%. Moreover, the Li/CNT electrode retains practical areal and gravimetric capacities of 10 mA h cm?2 and 2830 mA h g?1 (vs the mass of electrode), respectively, with 90.9% Li utilization for 1000 cycles at a current density of 10 mA cm?2. It is demonstrated that the robust and expandable nature is a distinguishing feature of the CNT paper as compared to other 3D scaffolds, and is a key factor that leads to the improved electrochemical performance of the Li/CNT anodes.  相似文献   

15.
Transition metal oxides have recently received great attention for application in advanced lithium‐ion batteries (LIBs) and oxygen evolution reaction (OER). Herein, the ethylenediaminetetraacetic cobalt complex as a precursor to synthesize ultrafine Co3O4 nanoparticles encapsulated into a nitrogen‐doped carbon matrix (NC) composites is presented. The as‐prepared Co3O4/NC‐350 obtained by pyrolysis at 350 °C demonstrates superior rate performance (372 mAh g?1 at 5.0 A g?1) and high cycling stability (92% capacity retention after 300 cycles at 1.0 A g?1) as anode for LIBs. When evaluated as an electrocatalyst for OER, the Co3O4/NC‐350 achieves an overpotential of 298 mV at a current density of 10 mA cm?2. The NC‐encapsualted porous hierarchical structure assures fast and continuous electron transportation, high activity sites, and strong structural integrity. This works offers novel complex precursors for synthesizing transition metal–based electrodes for boosting electrochemical energy conversion and storage.  相似文献   

16.
An artificial lithium‐nitrate (LiNO3)‐rich layer (LN‐RL) is developed to address dendritic lithium (Li) growth by a fusing–infusing strategy, in which LiNO3 is loaded into stainless steel mesh and a Li‐metal anode (LN‐RL@Li) is obtained by casting this LN‐RL onto Li foil. The LN‐RL enables fast Li deposition kinetics in carbonates and endows LN‐RL@Li with excellent cycleability. The underneath mechanism on the contribution of LN‐RL is uncovered by detailed characterizations combining with theoretical simulations. The LN‐RL promotes the desolvation and capacitive adsorption of Li ions and induces in‐plane Li growth along the edges of preplated Li with planar morphology. The improved cycleability of LN‐RL(@Li) is demonstrated by Li∥Cu cell that presents a coulombic efficiency of 97.2% after 280 cycles and Li∥Li cell that proceeds over 1000 h at 0.5 mA cm?2 in carbonates. Additionally, the Li∥LiFePO4 cell shows a capacity retention of 58% after 400 cycles at 1 C (1 C = 170 mA g?1), compared to the 35% after 180 cycles for the control. This work presents not only a promising strategy for practical applications of Li‐metal batteries, but also a new understanding on the role of nitrate in Li plating/stripping kinetics.  相似文献   

17.
Sodium (Na) metal anodes stand out with their remarkable capacity and natural abundance. However, the dendritic Na growth, infinite dimensional changes, and low Coulombic efficiency (CE) present key bottlenecks plaguing practical applications. Here, heteroatom‐doped (nitrogen, sulfur) hollow carbon fibers (D‐HCF) are rationally synthesized as a nucleation‐assisting host to enable a highly reversible Na metal. The “sodiophilic” functional groups introduced by the heteroatom‐doping and large surface area (≈1052 m2 g?1) synchronously contribute to a homogenous plating morphology with dissipated local current density. High “sodiophilicity” of the D‐HCF is confirmed by first‐principle calculations and experimental results, where strong adsorption energy of ?3.52 eV with low Na+ nucleation overpotential of 3.2 mV at 0.2 mA cm?2 is realized. As such, highly reversible plating/stripping is achieved at 1.0 mA cm?2 with average CE approximating 99.52% over 600 cycles. The as‐assembled Na@D‐HCF symmetric cells exhibit a prolonged lifetime for 1000 h. A full‐cell paired with Na3V2(PO4)3 cathode further demonstrates stable electrochemical behavior for 200 cycles at 1 C along with excellent rate performance (102 mAh g?1 at 5 C). The results clearly show the effectiveness of the D‐HCF in manipulating Na+ deposition and thus the significance of nucleation control in realizing dendrite‐free metal anodes.  相似文献   

18.
Lithium metal–sulfur (Li–S) batteries are attracting broad interest because of their high capacity. However, the batteries experience the polysulfide shuttle effect in cathode and dendrite growth in the Li metal anode. Herein, a bifunctional and tunable mesoporous carbon sphere (MCS) that simultaneously boosts the performance of the sulfur cathode and the Li anode is designed. The MCS homogenizes the flux of Li ions and inhibits the growth of Li dendrites due to its honeycomb structure with high surface area and abundance of nitrogen sites. The Li@MCS cell exhibits a small overpotential of 29 mV and long cycling performance of 350 h under the current density of 1 mA cm‐2. Upon covering one layer of amorphous carbon on the MCS (CMCS), an individual carbon cage is able to encapsulate sulfur inside and reduce the polysulfide shuttle, which improves the cycling stability of the Li–S battery. As a result, the S@CMCS has a maximum capacity of 411 mAh g‐1 for 200 cycles at a current density of 3350 mA g‐1. Based on the excellent performance, the full Li–S cell assembled with Li@MCS anode and S@CMCS cathode shows much higher capacity than a cell assembled with Li@Cu anode and S@CMCS cathode.  相似文献   

19.
Lithium (Li) metal is regarded as a “Holy Grail” electrode for next‐generation high‐energy‐density batteries. However, the electrochemical behavior of the Li anode under a practical working state is poorly understood, leading to a gap in the design strategy and the aim of efficient Li anodes. The electrochemical diagram to reveal failure mechanisms of ultrathin Li in pouch cells is demonstrated. The working mode of the Li metal anode ranging from 1.0 mA cm?2/1.0 mAh cm?2 (28.0 mA/28.0 mAh) to 10.0 mA cm?2/10.0 mAh cm?2 (280.0 mA/280.0 mAh) is investigated and divided into three categories: polarization, transition, and short‐circuit zones. Powdering and the induced polarization are the main reasons for the failure of the Li electrode at small current density and capacity, while short‐circuit occurs with the damage of the separator leading to safety concerns being dominant at large current and capacity. The electrochemical diagram is attributed from the distinctive plating/stripping behaviors of Li metal, accompanied by dendrites thickening and/or lengthening, and heterogeneous distribution of dendrites. A clear understanding in the electrochemical diagram of ultrathin Li is the primary step to rationally design an effective Li electrode and render a Li metal battery with high energy density, long lifespan, and enhanced safety.  相似文献   

20.
Li metal is the optimal choice as an anode due to its high theoretical capacity, but it suffers from severe dendrite growth, especially at high current rates. Here, an ionic gradient and lithiophilic inter‐phase film is developed, which promises to produce a durable and high‐rate Li‐metal anode. The film, containing an ionic‐conductive Li0.33La0.56TiO3 nanofiber (NF) layer on the top and a thin lithiophilic Al2O3 NF layer on the bottom, is fabricated with a sol–gel electrospinning method followed by sintering. During cycling, the top layer forms a spatially homogenous ionic field distribution over the anode, while the bottom layer reduces the driving force of Li‐dendrite formation by decreasing the nucleation barrier, enabling dendrite‐free plating‐stripping behavior over 1000 h at a high current density of 5 mA cm?2. Remarkably, full cells of Li//LiNi0.8Co0.15Al0.05O2 exhibit a high capacity of 133.3 mA h g?1 at 5 C over 150 cycles, contributing a step forward for high‐rate Li‐metal anodes.  相似文献   

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