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In situ weaving an all‐carbon graphdiyne coat on a silicon anode is scalably realized under ultralow temperature (25 °C). This economical strategy not only constructs 3D all‐carbon mechanical and conductive networks with reasonable voids for the silicon anode at one time but also simultaneously forms a robust interfacial contact among the electrode components. The intractable problems of the disintegrations in the mechanical and conductive networks and the interfacial contact caused by repeated volume variations during cycling are effectively restrained. The as‐prepared electrode demostrates the advantages of silicon regarding capacity (4122 mA h g?1 at 0.2 A g?1) with robust capacity retention (1503 mA h g?1) after 1450 cycles at 2 A g?1, and a commercial‐level areal capacity up to 4.72 mA h cm?2 can be readily approached. Furthermore, this method shows great promises in solving the key problems in other high‐energy‐density anodes.  相似文献   

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Failure mechanisms associated with silicon‐based anodes are limiting the implementation of high‐capacity lithium‐ion batteries. Understanding the aging mechanism that deteriorates the anode performance and introducing novel‐architectured composites offer new possibilities for improving the functionality of the electrodes. Here, the characterization of nano‐architectured composite anode composed of active amorphous silicon domains (a‐Si, 20 nm) and crystalline iron disilicide (c‐FeSi2, 5–15 nm) alloyed particles dispersed in a graphite matrix is reported. This unique hierarchical architecture yields long‐term mechanical, structural, and cycling stability. Using advanced electron microscopy techniques, the nanoscale morphology and chemical evolution of the active particles upon lithiation/delithiation are investigated. Due to the volumetric variations of Si during lithiation/delithiation, the morphology of the a‐Si/c‐FeSi2 alloy evolves from a core‐shell to a tree‐branch type structure, wherein the continuous network of the active a‐Si remains intact yielding capacity retention of 70% after 700 cycles. The root cause of electrode polarization, initial capacity fading, and electrode swelling is discussed and has profound implications for the development of stable lithium‐ion batteries.  相似文献   

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Metal molybdates nanostructures hold great promise as high‐performance electrode materials for next‐generation lithium‐ion batteries. In this work, the facial design and synthesis of monodisperse FeMoO4 nanocubes with the edge lengths of about 100 nm have been successfully prepared and present as a novel anode material for highly efficient and reversible lithium storage. Well‐defined single‐crystalline FeMoO4 with high uniformity are first obtained as nanosheets and then self‐aggregated into nanocubes. The morphology of the product is largely controlled by the experimental parameters, such as the reaction temperature and time, the ratio of reactant, the solution viscosity, etc. The molybdate nanostructure would effectively promote the insertion of lithium ions and withstand volume variation upon prolonged charge/discharge cycling. As a result, the FeMoO4 nanocubes exhibit high reversible capacities of 926 mAh g−1 after 80 cycles at a current density of 100 mA g−1 and remarkable rate performance, which indicate that the FeMoO4 nanocubes are promising materials for high‐power lithium‐ion battery applications.  相似文献   

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Silicon has been intensively studied as an anode material for lithium‐ion batteries (LIB) because of its exceptionally high specific capacity. However, silicon‐based anode materials usually suffer from large volume change during the charge and discharge process, leading to subsequent pulverization of silicon, loss of electric contact, and continuous side reactions. These transformations cause poor cycle life and hinder the wide commercialization of silicon for LIBs. The lithiation and delithiation behaviors, and the interphase reaction mechanisms, are progressively studied and understood. Various nanostructured silicon anodes are reported to exhibit both superior specific capacity and cycle life compared to commercial carbon‐based anodes. However, some practical issues with nanostructured silicon cannot be ignored, and must be addressed if it is to be widely used in commercial LIBs. This Review outlines major impactful work on silicon‐based anodes, and the most recent research directions in this field, specifically, the engineering of silicon architectures, the construction of silicon‐based composites, and other performance‐enhancement studies including electrolytes and binders. The burgeoning research efforts in the development of practical silicon electrodes, and full‐cell silicon‐based LIBs are specially stressed, which are key to the successful commercialization of silicon anodes, and large‐scale deployment of next‐generation high energy density LIBs.  相似文献   

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Dendrite and interfacial reactions have affected zinc (Zn) metal anodes for rechargeable batteries many years. Here, these obstacles are bypassed via adopting an intrinsically safe trimethyl phosphate (TMP)‐based electrolyte to build a stable Zn anode. Along with cycling, pristine Zn foil is gradually converted to a graphene‐analogous deposit via TMP surfactant and a Zn phosphate molecular template. This novel Zn anode morphology ensures long‐term reversible plating/stripping performance over 5000 h, a rate capability of 5 mA cm?2, and a remarkably high Coulombic efficiency (CE) of ≈99.57% without dendrite formation. As a proof‐of‐concept, a Zn–VS2 full cell demonstrates an ultralong lifespan, which provides an alternative for electrochemical energy storage devices.  相似文献   

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The CuS(x wt%)@Cu‐BTC (BTC = 1,3,5‐benzenetricarboxylate; x = 3, 10, 33, 58, 70, 99.9) materials are synthesized by a facile sulfidation reaction. The composites are composed of octahedral Cu3(BTC)2·(H2O)3 (Cu‐BTC) with a large specific surface area and CuS with a high conductivity. The as‐prepared CuS@Cu‐BTC products are first applied as the anodes of lithium‐ion batteries (LIBs). The synergistic effect between Cu‐BTC and CuS components can not only accommodate the volume change and stress relaxation of electrodes but also facilitate the fast transport of Li ions. Thus, it can greatly suppress the transformation process from Li2S to polysulfides by improving the reversibility of the conversion reaction. Benefiting from the unique structural features, the optimal CuS(70 wt%)@Cu‐BTC sample exhibits a remarkably improved electrochemical performance, showing an over‐theoretical capacity up to 1609 mAh g?1 after 200 cycles (100 mA g?1) with an excellent rate‐capability of ≈490 mAh g?1 at 1000 mA g?1. The outstanding LIB properties indicate that the CuS(70 wt%)@Cu‐BTC sample is a highly desirable electrode material candidate for high‐performance LIBs.  相似文献   

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A novel anode material for lithium‐ion batteries derived from aromatic imides with multicarbonyl group conjugated with aromatic core structure is reported, benzophenolne‐3,3′,4,4′‐tetracarboxylimide oligomer (BTO). It could deliver a reversible capacity of 829 mA h g?1 at 42 mA g?1 for 50 cycles with a stable discharge plateaus ranging from 0.05–0.19 V versus Li+/Li. At higher rates of 420 and 840 mA g?1, it can still exhibit excellent cycling stability with a capacity retention of 88% and 72% after 1000 cycles, delivering capacity of 559 and 224 mA h g?1. In addition, a rational prediction of the maximum amount of lithium intercalation is proposed and explored its possible lithium storage mechanism.  相似文献   

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Here, ZnFe2O4 double‐shell hollow microspheres are designed to accommodate the large volume expansion during lithiation. A facile and efficient vapor‐phase polymerization method has been developed to coat the ZnFe2O4 hollow spheres with polypyrrole (PPY). The thin PPY coating improves not only the electronic conductivity but also the structural integrity, and thus the cycling stability of the ZnFe2O4 hollow spheres. Our work sheds light on how to enhance the electrochemical performance of transition metal oxide‐based anode materials by designing delicate nanostructures.  相似文献   

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The fabrication of silicon (Si) anode materials derived from high silica‐containing plants enables effective utilization of subsidiary agricultural products. However, the electrochemical performances of synthesized Si materials still require improvement and thus need further structural design and morphology modifications, which inevitably increase preparation time and economic cost. Here, the conversion of corn leaves into Si anode materials is reported via a simple aluminothermic reduction reaction without other modifications. The obtained Si material inherits the structural characteristics of the natural corn leaf template and has many inherent advantages, such as high porosity, amorphous/crystalline mixture structure, and high‐valence SiOx residuals, which significantly enhance the material's structural stability and electrode adhesive strength, resulting in superior electrochemical performances. Rate capability tests show that the material delivers a high capacity of 1200 mA h g?1 at 8 A g?1 current density. After 300 cycles at 0.5 A g?1, the material maintains a high specific capacity of 2100 mA h g?1, with nearly 100% capacity retention during long‐term cycling. This study provides an economical route for the industrial production of Si anode materials for Lithium‐Ion batteries.  相似文献   

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To address the challenge of huge volume change and unstable solid electrolyte interface (SEI) of silicon in cycles, causing severe pulverization, this paper proposes a “double‐shell” concept. This concept is designed to perform dual functions on encapsulating volume change of silicon and stabilizing SEI layer in cycles using double carbon shells. Double carbon shells coated Si nanoparticles (DCS‐Si) are prepared. Inner carbon shell provides finite inner voids to allow large volume changes of Si nanoparticles inside of inner carbon shell, while static outer shell facilitates the formation of stable SEI. Most importantly, intershell spaces are preserved to buffer volume changes and alleviate mechanical stress from inner carbon shell. DCS‐Si electrodes display a high rechargeable specific capacity of 1802 mAh g−1 at a current rate of 0.2 C, superior rate capability and good cycling performance up to 1000 cycles. A full cell of DCS‐Si//LiNi0.45Co0.1Mn1.45O4 exhibits an average discharge voltage of 4.2 V, a high energy density of 473.6 Wh kg−1, and good cycling performance. Such double‐shell concept can be applied to synthesize other electrode materials with large volume changes in cycles by simultaneously enhancing electronic conductivity and controlling SEI growth.  相似文献   

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With extremely high specific capacity, silicon has attracted enormous interest as a promising anode material for next‐generation lithium‐ion batteries. However, silicon suffers from a large volume variation during charge/discharge cycles, which leads to the pulverization of the silicon and subsequent separation from the conductive additives, eventually resulting in rapid capacity fading and poor cycle life. Here, it is shown that the utilization of a self‐healable supramolecular polymer, which is facilely synthesized by copolymerization of tert‐butyl acrylate and an ureido‐pyrimidinone monomer followed by hydrolysis, can greatly reduce the side effects caused by the volume variation of silicon particles. The obtained polymer is demonstrated to have an excellent self‐healing ability due to its quadruple‐hydrogen‐bonding dynamic interaction. An electrode using this self‐healing supramolecular polymer as binder exhibits an initial discharge capacity as high as 4194 mAh g−1 and a Coulombic efficiency of 86.4%, and maintains a high capacity of 2638 mAh g−1 after 110 cycles, revealing significant improvement of the electrochemical performance in comparison with that of Si anodes using conventional binders. The supramolecular binder can be further applicable for silicon/carbon anodes and therefore this supramolecular strategy may increase the choice of amendable binders to improve the cycle life and energy density of high‐capacity Li‐ion batteries.  相似文献   

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