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1.
The success of Li–air/O2 batteries has brought extensive attention to the development of various promising non‐Li metal–O2 batteries, such as Zn–O2, Al–O2, Mg–O2 batteries, etc., which have exhibited unique advantages, such as low production cost, high energy density, and much enhanced safety. The versatile non‐Li metal–O2 batteries provide a better opportunity for meeting the practical requirements for sustainable energy supplies in various applications. A high‐performance cathode in non‐Li metal–O2 batteries that can effectively trigger both oxygen reduction and evolution reactions and thus boost the overall battery performance is of great research interest. In this article, a comprehensive review on the development of Li‐free metal–O2 batteries and particularly focusing on the oxygen catalytic cathodes for both primary and secondary non‐Li metal–O2 batteries is carefully performed. The current challenges and potential solutions are also outlined and proposed. Through carefully selecting and rationally designing promising catalytic cathodes, a series of non‐Li metal–oxygen batteries toward practical energy storage applications are highly anticipated.  相似文献   

2.
There is a growing concern about the cyclability and safety, in particular, of the high‐energy density lithium–metal batteries. This concern is even greater for Li–O2 batteries because O2 that is transported from the cathode to the anode compartment, can exacerbate side reactions and dendrite growth of the lithium metal anode. The key to solving this dilemma lays in tailoring the solid electrolyte interphase (SEI) formed on the lithium metal anode in Li–O2 batteries. Here it is reported that a new electrolyte, formed from LiFSI as the salt and a mixture of tetraethylene glycol dimethyl ether and polymeric ionic liquid of P[C5O2NMA,11]FSI as the solvent, can produce a stable electrode (both cathode and anode)|electrolyte interface in Li–O2 batteries. Specifically, this new electrolyte, when in contact with lithium metal anodes, has the ability to produce a uniform SEI with high ionic conductivity for Li+ transport and desired mechanical property for suppression of dendritic lithium growth. Moreover, the electrolyte possesses a high oxidation tolerance that is very beneficial to the oxygen electrochemistry on the cathode of Li–O2 batteries. As a result, enhanced reversibility and cycle life are realized for the resultant Li–O2 batteries.  相似文献   

3.
Energy storage challenges have triggered growing interest in various battery technologies and electrocatalysis. As a particularly promising variety, the Li–O2 battery with an extremely high energy density is of great significance, offering tremendous opportunities to improve cell performance via understanding catalytic mechanisms and the exploration of new materials. Furthermore, focus on nonaqueous electrolyte‐based Li–O2 batteries has markedly intensified since there could be a higher probability of commercialization, compared to that of solid‐state or aqueous electrolytes. The recent advancements of the nonaqueous Li–O2 battery in terms of fundamental understanding and material challenges, including electrolyte stability, water effect, and noncarbon cathode materials are summarized in this review. Further, the current status of water impact on discharge products, possible mechanisms, and parasitic reactions in nonaqueous electrolytes are reviewed for the first time. The key challenges of noncarbon oxygen electrode materials, such as noble metals and metal oxides‐based cathodes, transition metals, transition metal compounds (carbides, oxides) based cathodes as well as noncarbon supported catalysts are discussed. This review concludes with a perspective on future research directions for nonaqueous Li–O2 batteries.  相似文献   

4.
Although the rechargeable lithium–oxygen (Li–O2) batteries have extremely high theoretical specific energy, the practical application of these batteries is still limited by the instability of their carbon‐based air‐electrode, Li metal anode, and electrodes, toward reduced oxygen species. Here a simple one‐step in situ electrochemical precharging strategy is demonstrated to generate thin protective films on both carbon nanotubes (CNTs), air‐electrodes and Li metal anodes simultaneously under an inert atmosphere. Li–O2 cells after such pretreatment demonstrate significantly extended cycle life of 110 and 180 cycles under the capacity‐limited protocol of 1000 mA h g?1 and 500 mA h g?1, respectively, which is far more than those without pretreatment. The thin‐films formed from decomposition of electrolyte during in situ electrochemical precharging processes in an inert environment, can protect both CNTs air‐electrode and Li metal anode prior to conventional Li–O2 discharge/charge cycling, where reactive reduced oxygen species are formed. This work provides a new approach for protection of carbon‐based air‐electrodes and Li metal anodes in practical Li–O2 batteries, and may also be applied to other battery systems.  相似文献   

5.
The conventional electrolyte of 1 m lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) in dimethyl sulfoxide (DMSO) is unstable against the Li metal anode and therefore cannot be used directly in practical Li–O2 batteries. Here, we demonstrate that a highly concentrated electrolyte based on LiTFSI in DMSO (with a molar ratio of 1:3) can greatly improve the stability of the Li metal anode against DMSO and significantly improve the cycling stability of Li–O2 batteries. This highly concentrated electrolyte contains no free DMSO solvent molecules, but only complexes of (TFSI?)a ? Li+? (DMSO)b (where a + b = 4), and thus enhances their stability with Li metal anodes. In addition, such salt–solvent complexes have higher Gibbs activation energy barriers than the free DMSO solvent molecules, indicating improved stability of the electrolyte against the attack of superoxide radical anions. Therefore, the stability of this highly concentrated electrolyte at both Li metal anodes and carbon‐based air electrodes has been greatly enhanced, resulting in improved cycling performance of Li–O2 batteries. The fundamental stability of the electrolyte in the absence of free‐solvent against the chemical and electrochemical reactions can also be used to enhance the stability of other electrochemical systems.  相似文献   

6.
Recently, various approaches for adding redox mediators to electrolytes and introducing protective layers onto Li metal have been suggested to overcome the low energy efficiency and poor cycle life of Li–O2 batteries. However, the catalytic effect of the redox mediator for oxygen evolution gradually deteriorates during repeated cycling owing to its decomposition at the surfaces of both the oxygen electrode (cathode) and the Li metal electrode (anode). Here, optimized Li–O2 batteries are designed with a continuously effective redox mediator and a stable protective layer for the Li metal electrode by optimizing the LiBr concentration and introducing a graphene–polydopamine composite layer, respectively. These synergistic modifications lead to a reduction of the charge potential to below 3.4 V and significantly improve the stability and cycle life of Li–O2 batteries. Consequently, a high energy efficiency of above 80% is maintained over 150 cycles. Herein, it is confirmed that the relationships between all the battery materials should be understood in order to improve the performance of Li–O2 batteries.  相似文献   

7.
The development of high‐efficiency bifunctional electrocatalyst for oxygen reduction and evolution reactions (ORR/OER) is critical for rechargeable metal–air batteries, a typical electrochemical energy storage and conversion technology. This work reports a general approach for the synthesis of Pd@PdO–Co3O4 nanocubes using the zeolite‐type metal–organic framework (MOF) as a template. The as‐synthesized materials exhibit a high electrocatalytic activity toward OER and ORR, which is comparable to those of commercial RuO2 and Pt/C electrocatalysts, while its cycle performance and stability are much higher than those of commercial RuO2 and Pt/C electrocatalysts. Various physicochemical characterizations and density functional theory calculations indicate that the favorable electrochemical performance of the Pd@PdO–Co3O4 nanocubes is mainly attributed to the synergistic effect between PdO and the robust hollow structure composed of interconnected crystalline Co3O4 nanocubes. This work establishes an efficient approach for the controlled design and synthesis of MOF‐templated hybrid nanomaterials, and provides a great potential for developing high‐performance electrocatalysts in energy storage and conversion.  相似文献   

8.
Li‐O2 batteries are promising next‐generation energy storage systems because of their exceptionally high energy density (≈3500 W h kg?1). However, to achieve stable operation, grand challenges remain to be resolved, such as preventing electrolyte decomposition and degradation of carbon, a commonly used air electrode in Li‐O2 batteries. In this work, using in situ differential electrochemical mass spectrometry, it is demonstrated that the application of a ZnO coating on the carbon electrode can effectively suppress side reactions occurring in the Li‐O2 battery. By probing the CO2 evolution during charging of 13C‐labeled air electrodes, the major sources of parasitic reactions are precisely identified, which further reveals that the ZnO coating retards the degradation of both the carbon electrode and electrolyte. The successful suppression of the degradation results in a higher oxygen efficiency, leading to enhanced stability for more than 100 cycles. Nevertheless, the degradation of the carbon electrode is not completely prevented by the coating, because the Li2O2 discharge product gradually grows at the interface between the ZnO and carbon, which eventually results in detachment of the ZnO particles from the electrode and subsequent deterioration of the performance. This finding implies that surface protection of the carbon electrode is a viable option to enhance the stability of Li‐O2 batteries; however, fundamental studies on the growth mechanism of the discharge product on the carbon surface are required along with more effective coating strategies.  相似文献   

9.
Transition metal oxides hold great promise as high‐energy anodes in next‐generation lithium‐ion batteries. However, owing to the inherent limitations of low electronic/ionic conductivities and dramatic volume change during charge/discharge, it is still challenging to fabricate practically viable compacted and thick TMO anodes with satisfactory electrochemical performance. Herein, with mesoporous cobalt–boride nanoflakes serving as multifunctional bridges in ZnCo2O4 micro‐/nanospheres, a compacted ZnCo2O4/Co–B hybrid structure is constructed. Co–B nanoflakes not only bridge ZnCo2O4 nanoparticles and function as anchors for ZnCo2O4 micro‐/nanospheres to suppress the severe volume fluctuation, they also work as effective electron conduction bridges to promote fast electron transportation. More importantly, they serve as Li+ transfer bridges to provide significantly boosted Li+ diffusivity, evidenced from both experimental kinetics analysis and density functional theory calculations. The mesopores within Co–B nanoflakes help overcome the large Li+ diffusion barriers across 2D interfaces. As a result, the ZnCo2O4/Co–B electrode delivers high gravimetric/volumetric/areal capacities of 995 mAh g?1/1450 mAh cm?3/5.10 mAh cm?2, respectively, with robust rate capability and long‐term cyclability. The distinct interfacial design strategy provides a new direction for designing compacted conversion‐type anodes with superior lithium storage kinetics and stability for practical applications.  相似文献   

10.
The nonaqueous lithium–oxygen (Li–O2) battery is considered as one of the most promising candidates for next‐generation energy storage systems because of its very high theoretical energy density. However, its development is severely hindered by large overpotential and limited capacity, far less than theory, caused by sluggish oxygen redox kinetics, pore clogging by solid Li2O2 deposition, inferior Li2O2/cathode contact interface, and difficult oxygen transport. Herein, an open‐structured Co9S8 matrix with sisal morphology is reported for the first time as an oxygen cathode for Li–O2 batteries, in which the catalyzing for oxygen redox, good Li2O2/cathode contact interface, favorable oxygen evolution, and a promising Li2O2 storage matrix are successfully achieved simultaneously, leading to a significant improvement in the electrochemical performance of Li–O2 batteries. The intrinsic oxygen‐affinity revealed by density functional theory calculations and superior bifunctional catalytic properties of Co9S8 electrode are found to play an important role in the remarkable enhancement in specific capacity and round‐trip efficiency for Li–O2 batteries. As expected, the Co9S8 electrode can deliver a high discharge capacity of ≈6875 mA h g?1 at 50 mA g?1 and exhibit a low overpotential of 0.57 V under a cutoff capacity of 1000 mA h g?1, outperforming most of the current metal‐oxide‐based cathodes.  相似文献   

11.
Lithium–oxygen batteries are in fact the only rechargeable batteries that can rival internal combustion engines, in terms of high energy density. However, they are still under development due to low‐efficiency and short lifetime issues. There are problems of side reactions on the cathode side, high reactivity of the Li anode with solution species, and consumption of redox mediators via reactions with metallic lithium. Therefore, efforts are made to protect/block the lithium metal anode in these cells, in order to mitigate side reactions. However, new approach is required in order to solve the problems mentioned above, especially the irreversible reactions of the redox mediators which are mandatory to these systems with the Li anode. Here, optimized bicompartment two solution cells are proposed, in which detrimental crossover between the cathode and anode is completely avoided. The Li metal anode is cycled in electrolyte solution containing fluorinated ethylene carbonate, in which its cycling efficiency is excellent. The cathode compartment contains ethereal solution with redox mediator that enables oxidation of Li2O2 at low potentials. The electrodes are separated by a solid electrolyte membrane, allowing free transport of Li ions. This approach increases cycle life of lithium oxygen cells and their energy efficiency.  相似文献   

12.
The critical challenges of Li‐O2 batteries lie in sluggish oxygen redox kinetics and undesirable parasitic reactions during the oxygen reduction reaction and oxygen evolution reaction processes, inducing large overpotential and inferior cycle stability. Herein, an elaborately designed 3D hierarchical heterostructure comprising NiCo2S4@NiO core–shell arrays on conductive carbon paper is first reported as a freestanding cathode for Li‐O2 batteries. The unique hierarchical array structures can build up multidimensional channels for oxygen diffusion and electrolyte impregnation. A built‐in interfacial potential between NiCo2S4 and NiO can drastically enhance interfacial charge transfer kinetics. According to density functional theory calculations, intrinsic LiO2‐affinity characteristics of NiCo2S4 and NiO play an importantly synergistic role in promoting the formation of large peasecod‐like Li2O2, conducive to construct a low‐impedance Li2O2/cathode contact interface. As expected, Li‐O2 cells based on NiCo2S4@NiO electrode exhibit an improved overpotential of 0.88 V, a high discharge capacity of 10 050 mAh g?1 at 200 mA g?1, an excellent rate capability of 6150 mAh g?1 at 1.0 A g?1, and a long‐term cycle stability under a restricted capacity of 1000 mAh g?1 at 200 mA g?1. Notably, the reported strategy about heterostructure accouplement may pave a new avenue for the effective electrocatalyst design for Li‐O2 batteries.  相似文献   

13.
Use of a protective coating on a lithium metal anode (LMA) is an effective approach to enhance its coulombic efficiency and cycling stability. Here, a facile approach to produce uniform silver nanoparticle‐decorated LMA for high‐performance Li metal batteries (LMBs) is reported. This effective treatment can lead to well‐controlled nucleation and the formation of a stable solid electrolyte interphase (SEI). Ag nanoparticles embedded in the surface of Li anodes induce uniform Li plating/stripping morphologies with reduced overpotential. More importantly, cross‐linked lithium fluoride‐rich interphase formed during Ag+ reduction enables a highly stable SEI layer. Based on the Ag‐LiF decorated anodes, LMBs with LiNi1/3Mn1/3Co1/3O2 cathode (≈1.8 mAh cm?2) can retain >80% capacity over 500 cycles. The similar approach can also be used to treat sodium metal anodes. Excellent stability (80% capacity retention in 10 000 cycles) is obtained for a Na||Na3V2(PO4)3 full cell using a Na‐Ag‐NaF/Na anode cycled in carbonate electrolyte. These results clearly indicate that synergetic control of the nucleation and SEI is an efficient approach to stabilize rechargeable metal batteries.  相似文献   

14.
For a long time lithium (Li) metal has been considered one of the most promising anodes for next‐generation rechargeable batteries. Despite decades of concentrated research, its practical application is still hindered by dendritic Li deposition and infinite volume change of Li metal anodes. Here, atomically dispersed metals doped graphene is synthesized to regulate Li metal nucleation and guide Li metal deposition. The single‐atom (SA) metals, supported on the nitrogen‐doped graphene can not only increase the Li adsorption energy of the localized area around the metal atomic sites with a moderate adsorption energy gradient but also improve the atomic structural stability of the overall materials by constructing a coordination mode of M‐Nx‐C (M, N, and C denoted as metal, nitrogen, and carbon atoms, respectively). As a result, the as‐obtained electrode exhibits an ultralow voltage hysteresis of 19 mV, a high average Coulombic efficiency of 98.45% over 250 cycles, and a stable Li plating/stripping performance even at a high current density of 4.0 mA cm?2. This work demonstrates the application of SA metal doping in the rational design of Li metal anodes and provides a new concept for further development of Li metal batteries.  相似文献   

15.
The infinite volume change and dendritic behavior in alkali metal anodes lead to low Coulombic efficiency and short‐circuit issues that significantly hamper renewed efforts at commercialization. Here, a dendrite‐free alkali metal anode, made by thermally preloading molten Li or Na into a 3D framework with high alkali wettability, is reported. In the mechanically robust 3D framework, carbon fiber (CF) serves as an electrical highway that provides fast charge transfer for the redox reaction. Through a facile solution‐based process, a SnO2 coating is introduced to modify the poor wetting behavior of the carbon framework and drastically improve both the electrochemical performance and reliability. The kinetic barrier to adhesion of molten alkali metals on the CF framework is eliminated by the mixed reaction with SnO2. The growth of dendrites is effectively repressed under the decreased local current density of the 3D framework. In full‐cell configurations with LiFePO4 cathodes, the Li–CF electrode shows reduced polarization and 90% capacity retention after 500 cycles in traditional carbonate electrolyte. Comparable improvements are also observed in 3D electrodes for Na metal batteries. These findings on a stable 3D carbon framework with improved wetting behavior provide significant practical implications for achieving safe and commercially viable alkali metal anodes.  相似文献   

16.
Silicon anodes are regarded as one of the most promising alternatives to graphite for high energy‐density lithium‐ion batteries (LIBs), but their practical applications have been hindered by high volume change, limited cycle life, and safety concerns. In this work, nonflammable localized high‐concentration electrolytes (LHCEs) are developed for Si‐based anodes. The LHCEs enable the Si anodes with significantly enhanced electrochemical performances comparing to conventional carbonate electrolytes with a high content of fluoroethylene carbonate (FEC). The LHCE with only 1.2 wt% FEC can further improve the long‐term cycling stability of Si‐based anodes. When coupled with a LiNi0.3Mn0.3Co0.3O2 cathode, the full cells using this nonflammable LHCE can maintain >90% capacity after 600 cycles at C/2 rate, demonstrating excellent rate capability and cycling stability at elevated temperatures and high loadings. This work casts new insights in electrolyte development from the perspective of in situ Si/electrolyte interphase protection for high energy‐density LIBs with Si anodes.  相似文献   

17.
Sodium (Na) metal, which possesses a high theoretical capacity and the lowest electrochemical potential, is regarded as a promising anode material for Na–metal batteries. However, both Na dendrite growth and large volume change in cycling have severely impeded its practical applications. This study demonstrates that a 3D flexible carbon (C) felt which is already commercialized in large‐scale can be employed as a host for prestoring Na via a melt infusion strategy, through which a Na/C composite anode is obtained. The resulting anode exhibits a stable voltage profile and a small hysteresis over 120 cycles in carbonate‐based electrolytes in symmetrical cells owing to the fact that the metallic Na is confined in a conductive carbon felt host, which increases the Na+ deposition sites to lower the effective current density and render a uniform Na nucleation, restricting the dimension change in electrochemical cycling. More importantly, effective inhibition of Na dendrite growth and large volume change is achieved. When coupled with a Na0.67Ni0.33Mn0.67O2 cathode, the Na/C composite demonstrates a good suitability in full cells. This work provides an alternative option for the fabrication of stable Na metal anodes, which is of great significance for the practical applications of Na metal anodes in high‐energy‐density batteries.  相似文献   

18.
Cathode materials with high energy density, long cycle life, and low cost are of top priority for energy storage systems. The Li‐rich transition metal (TM) oxides achieve high specific capacities by redox reactions of both the TM and oxygen ions. However, the poor reversible redox reaction of the anions results in severe fading of the cycling performance. Herein, the vacancy‐containing Na4/7[Mn6/7(?Mn)1/7]O2 (?Mn for vacancies in the Mn? O slab) is presented as a novel cathode material for Na‐ion batteries. The presence of native vacancies endows this material with attractive properties including high structural flexibility and stability upon Na‐ion extraction and insertion and high reversibility of oxygen redox reaction. Synchrotron X‐ray absorption near edge structure and X‐ray photoelectron spectroscopy studies demonstrate that the charge compensation is dominated by the oxygen redox reaction and Mn3+/Mn4+ redox reaction separately. In situ synchrotron X‐ray diffraction exhibits its zero‐strain feature during the cycling. Density functional theory calculations further deepen the understanding of the charge compensation by oxygen and manganese redox reactions and the immobility of the Mn ions in the material. These findings provide new ideas on searching for and designing materials with high capacity and high structural stability for novel energy storage systems.  相似文献   

19.
All‐solid‐state batteries with an alkali metal anode have the potential to achieve high energy density. However, the onset of dendrite formation limits the maximum plating current density across the solid electrolyte and prevents fast charging. It is shown that the maximum plating current density is related to the interfacial resistance between the solid electrolyte and the metal anode. Due to their high ionic conductivity, low electronic conductivity, and stability against sodium metal, Na‐β″‐alumina ceramics are excellent candidates as electrolytes for room‐temperature all‐solid‐state batteries. Here, it is demonstrated that a heat treatment of Na‐β″‐alumina ceramics in argon atmosphere enables an interfacial resistance <10 Ω cm2 and current densities up to 12 mA cm?2 at room temperature. The current density obtained for Na‐β″‐alumina is ten times higher than that measured on a garnet‐type Li7La3Zr2O12 electrolyte under equivalent conditions. X‐ray photoelectron spectroscopy shows that eliminating hydroxyl groups and carbon contaminations at the interface between Na‐β″‐alumina and sodium metal is key to reach such values. By comparing the temperature‐dependent stripping/plating behavior of Na‐β″‐alumina and Li7La3Zr2O12, the role of the alkali metal in governing interface kinetics is discussed. This study provides new insights into dendrite formation and paves the way for fast‐charging all‐solid‐state batteries.  相似文献   

20.
Lithium (Li) metal anodes are promising candidates for high‐energy‐density batteries. However, uncontrollable dendritic plating behavior and infinite volume expansion are hindering their practical applications. Herein, a novel CuO@Ti‐mesh (CTM) is prepared by microwave‐assisted reactions, followed by pressing on Li wafers, leading to Li/CuO@Ti‐mesh (LCTM) composite anodes. The lithiophilic CuO nanoflowers on Ti‐mesh provides evenly distributed nucleation sites, inducing uniform Li‐ion lateral plating, which can effectively inhibit the growth of Li dendrites and volume expansion during cycling. The as‐prepared LCTM composite anode exhibits high Coulombic efficiency (CE) of 94.2% at 10 mA cm‐2 over 90 cycles. Meanwhile, the LCTM anode shows a low overpotential of 50 mV at 10 mA cm‐2 over 16 000 cycles and a low overpotential of 90 and 250 mV even at ultrahigh current densities of 20 and 40 mA cm‐2. When paired with Li4Ti5O12 (LTO), it enhances the capacity retention of LTO/Li wafer full cells by about two times from 36.6% to 73.0% and 42.0% to 80.0% at 5C and 10C with long‐term cycling. It is hoped that this LCTM anode with ultrahigh rates and ultralong cycle life may put Li‐metal anode forward to practical applications, such as in Li–S, Li‐air batteries, etc.  相似文献   

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