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1.
Utilizing cost-effective raw materials to prepare high-performance silicon-based anode materials for lithium-ion batteries (LIBs) is both challenging and attractive. Herein, a porous SiFe@C (pSiFe@C) composite derived from low-cost ferrosilicon is prepared via a scalable three-step procedure, including ball milling, partial etching, and carbon layer coating. The pSiFe@C material integrates the advantages of the mesoporous structure, the partially retained FeSi2 conductive phase, and a uniform carbon layer (12–16 nm), which can substantially alleviate the huge volume expansion effect in the repeated lithium-ion insertion/extraction processes, effectively stabilizing the solid–electrolyte interphase (SEI) film and markedly enhancing the overall electronic conductivity of the material. Benefiting from the rational structure, the obtained pSiFe@C hybrid material delivers a reversible capacity of 1162.1 mAh g−1 after 200 cycles at 500 mA g−1, with a higher initial coulombic efficiency of 82.30 %. In addition, it shows large discharge capacities of 803.1 and 600.0 mAh g−1 after 500 cycles at 2 and 4 A g−1, respectively, manifesting an excellent electrochemical lithium storage. This work provides a good prospect for the commercial production of silicon-based anode materials for LIBs with a high lithium-storage capacity.  相似文献   

2.
Transition metal oxide (TMO) anode materials in lithium-ion batteries (LIBs) usually suffer from serious volume expansion leading to the pulverization of structures, further giving rise to lower specific capacity and worse cycling stability. Herein, by introducing polyoxometalate (POM) clusters into TMOs and precisely controlling the amount of POMs, the MnZnCuOx-phosphomolybdic acid hybrid sub-1 nm nanosheets (MZC-PMA HSNSs) anode is successfully fabricated, where the special electron rich structure of POMs is conducive to accelerating the migration of lithium ions on the anode to obtain higher specific capacity, and the non-covalent interactions between POMs and TMOs make the HSNSs possess excellent structural and chemical stability, thus exhibiting outstanding electrochemical performance in LIBs, achieving a high reversible capacity (1157 mAh g−1 at 100 mA g−1) and an admirable long-term cycling stability at low and high current densities.  相似文献   

3.
Polyoxometalates (POMs)-based materials, with high theoretical capacities and abundant reversible multi-electron redox properties, are considered as promising candidates in lithium-ion storage. However, the poor electronic conductivity, low specific surface area and high solubility in the electrolyte limited their practical applications. Herein, a double-shelled hollow PMo12−SiO2@N−C nanofiber (PMo12−SiO2@N−C, where PMo12 is [PMo12O40]3−, N−C is nitrogen-doped carbon) was fabricated for the first time by combining coaxial electrospinning technique, thermal treatment and electrostatic adsorption. As an anode material for LIBs, the PMo12−SiO2@N−C delivered an excellent specific capacity of 1641 mA h g−1 after 1000 cycles under 2 A g−1. The excellent electrochemical performance benefited from the unique double-shelled hollow structure of the material, in which the outermost N−C shell cannot only hinder the agglomeration of PMo12, but also improve its electronic conductivity. The SiO2 inner shell can efficiently avoid the loss of active components. The hollow structure can buffer the volume expansion and accelerate Li+ diffusion during lithiation/delithiation process. Moreover, PMo12 can greatly reduce charge-resistance and facilitate electron transfer of the entire composites, as evidenced by the EIS kinetics study and lithium-ion diffusion analysis. This work paves the way for the fabrication of novel POM-based LIBs anode materials with excellent lithium storage performance.  相似文献   

4.
Two-dimensional molybdenum disulfide (MoS2) has been recognized as a promising anode material for lithium-ion batteries (LIBs) due to its high theoretical capacity, but its rapid capacity decay owing to poor conductivity, structure pulverization, and polysulfide dissolution presents significant challenges in practical applications. Herein, triple-layered hollow spheres in which MoS2 nanosheets are fully encapsulated between inner carbon and outer nitrogen-doped carbon (NC) were fabricated. Such an architecture provides high conductivity and efficient lithium-ion transfer. Moreover, the NC shell prevents aggregation and exfoliation of MoS2 nanosheets and thus maintains the integrity of the nanostructure during the charge/discharge process. As anode materials for LIBs, the C@MoS2@NC hollow spheres deliver a high reversible capacity (747 mA h g−1 after 100 cycles at 100 mA g−1) and excellent long-cycle performance (650 mA h g−1 after 1000 cycles at 1.0 A g−1), which confirm its potential for high-performance LIBs.  相似文献   

5.
The cost-efficient ZnMnO3 has attracted increasing attention as a prospective anode candidate for advanced lithium-ion batteries (LIBs) owing to its resourceful abundance, large lithium storage capacity and low operating voltage. However, its practical application is still seriously limited by the modest cycling and rate performances. Herein, a facile design to scalable synthesize unique one-dimensional (1D) mesoporous ZnMnO3 nanorods (ZMO-NRs) composed of nanoscale particles (≈11 nm) is reported. The 1D mesoporous structure and nanoscale building blocks of the ZMO-NRs effectively promote the transport of ions/electrons, accommodate severe volume changes, and expose more active sites for lithium storage. Benefiting from these appealing structural merits, the obtained ZMO-NRs anode exhibits excellent rate behavior (≈454 mAh g−1 at 2 A g−1) and ultra-long term cyclic performance (≈949.7 mAh g−1 even over 500 cycles at 0.5 A g−1) for efficient lithium storage. Additionally, the LiNi0.8Co0.1Mn0.1O2//ZMO-NRs full cell presents a practical energy density (≈192.2 Wh kg−1) and impressive cyclability with approximately 91 % capacity retention over 110 cycles. This highlights that the ZMO-NRs product is a highly promising high-rate and stable electrode candidate towards advanced LIBs in electronic devices and sustainable energy storage applications.  相似文献   

6.
Improving the performance of anode materials for lithium-ion batteries (LIBs) is a hotly debated topic. Herein, hollow Ni−Co skeleton@MoS2/MoO3 nanocubes (NCM-NCs), with an average size of about 193 nm, have been synthesized through a facile hydrothermal reaction. Specifically, MoO3/MoS2 composites are grown on Ni−Co skeletons derived from nickel–cobalt Prussian blue analogue nanocubes (Ni−Co PBAs). The Ni−Co PBAs were synthesized through a precipitation method and utilized as self-templates that provided a larger specific surface area for the adhesion of MoO3/MoS2 composites. According to Raman spectroscopy results, as-obtained defect-rich MoS2 is confirmed to be a metallic 1T-phase MoS2. Furthermore, the average particle size of Ni−Co PBAs (≈43 nm) is only about one-tenth of the previously reported particle size (≈400 nm). If assessed as anodes of LIBs, the hollow NCM-NC hybrids deliver an excellent rate performance and superior cycling performance (with an initial discharge capacity of 1526.3 mAh g−1 and up to 1720.6 mAh g−1 after 317 cycles under a current density of 0.2 A g−1). Meanwhile, ultralong cycling life is retained, even at high current densities (776.6 mAh g−1 at 2 A g−1 after 700 cycles and 584.8 mAh g−1 at 5 A g−1 after 800 cycles). Moreover, at a rate of 1 A g−1, the average specific capacity is maintained at 661 mAh g−1. Thus, the hierarchical hollow NCM-NC hybrids with excellent electrochemical performance are a promising anode material for LIBs.  相似文献   

7.
Lithium ion batteries (LIBs) at present still suffer from low rate capability and poor cycle life during fast ion insertion/extraction processes. Searching for high-capacity and stable anode materials is still an ongoing challenge. Herein, a facile strategy for the synthesis of ultrathin GeS2 nanosheets with the thickness of 1.1 nm is reported. When used as anodes for LIBs, the two-dimensional (2D) structure can effectively increase the electrode/electrolyte interface area, facilitate the ion transport, and buffer the volume expansion. Benefiting from these merits, the as-synthesized GeS2 nanosheets deliver high specific capacity (1335 mAh g−1 at 0.15 A g−1), extraordinary rate performance (337 mAh g−1 at 15 A g−1) and stable cycling performance (974 mAh g−1 after 200 cycles at 0.5 A g−1). Importantly, our fabricated Li-ion full cells manifest an impressive specific capacity of 577 mAh g−1 after 50 cycles at 0.1 A g−1 and a high energy density of 361 Wh kg−1 at a power density of 346 W kg−1. Furthermore, the electrochemical reaction mechanism is investigated by the means of ex-situ high-resolution transmission electron microscopy. These results suggest that GeS2 can use to be an alternative anode material and encourage more efforts to develop other high-performance LIBs anodes.  相似文献   

8.
Low-cost Si-based anode materials with excellent electrochemical lithium storage present attractive prospects for lithium-ion batteries (LIBs). Herein, porous Si-Cu3Si-Cu microsphere@C composites are designed and prepared by means of an etching/electroless deposition and subsequent carbon coating. The composites show a core–shell structure, with a porous Si/Cu microsphere core surrounded by the N-doped carbon shell. The Cu and Cu3Si nanoparticles are embedded inside porous silicon microspheres, forming the porous Si/Cu microsphere core. The microstructure and lithium storage performance of porous Si-Cu3Si-Cu microsphere@C composites can be effectively tuned by changing electroless deposition time. The Si-Cu3Si-Cu microsphere@C composite prepared with 12 min electroless deposition delivers a reversible capacity of 627 mAh g−1 after 200 cycles at 2 A g−1, showing an enhanced lithium storage ability. The superior lithium storage performance of the Si-Cu3Si-Cu microsphere@C composite can be ascribed to the improved electronic conductivity, enhanced mechanical stability, and better buffering against the large volume change in the repeated lithiation/delithiation processes.  相似文献   

9.
Transition metal oxides have vastly limited practical application as electrode materials for lithium-ion batteries (LIBs) due to their rapid capacity decay. Here, a versatile strategy to mitigate the volume expansion and low conductivity of Fe3O4 by coating a thin carbon layer on the surface of Fe3O4 nanosheets (NSs) was employed. Owing to the 2D core–shell structure, the Fe3O4@C NSs exhibit significantly improved rate performance and cycle capability compared with bare Fe3O4 NSs. After 200 cycles, the discharge capacity at 0.5 A g−1 was 963 mA h g−1 (93 % retained). Moreover, the reaction mechanism of lithium storage was studied in detail by ex situ XRD and HRTEM. When coupled with a commercial LiFePO4 cathode, the resulting full cell retains a capacity of 133 mA h g−1 after 100 cycles at 0.1 A g−1, which demonstrates its superior energy storage performance. This work provides guidance for constructing 2D metal oxide/carbon composites with high performance and low cost for the field of energy storage.  相似文献   

10.
The fast-charging capability of rechargeable batteries is greatly limited by the sluggish ion transport kinetics in anode materials. Here we develop an iodized polyacrylonitrile (I-PAN) anode that can boost the bulk/interphase lithium (Li)-ion diffusion kinetics and accelerate Li-ion desolvation process to realize high-performance fast-charging Li-ion batteries. The iodine immobilized in I-PAN framework expands ion transport channels, compresses the electric double layer, and changes the inner Helmholtz plane to form LiF/LiI-rich solid electrolyte interphase layer. The dissolved iodine ions in the electrolyte self-induced by the interfacial nucleophilic substitution of PF6 not only promote the Li-ion desolvation process, but also reuse the plated/dead Li formed on the anode under fast-charging conditions. Consequently, the I-PAN anode exhibits a high capacity of 228.5 mAh g−1 (39 % of capacity at 0.5 A g−1 delivered in 18 seconds) and negligible capacity decay for 10000 cycles at 20 A g−1. The I-PAN||LiNi0.8Co0.1Mn0.1O2 full cell shows excellent fast-charging performance with attractive capacities and negligible capacity decay for 1000 cycles at extremely high rates of 5 C and 10 C (1 C=180 mA g−1). We also demonstrate high-performance fast-charging sodium-ion batteries using I-PAN anodes.  相似文献   

11.
Organic lithium ion batteries (LIBs) are considered as one of the next-generation green electrochemical energy storage (EES) devices. However, obtaining both high capacity and long-term cyclability is still the bottleneck of organic electrode materials for LIBs because of weak structural and chemical stability and low conductivity. Covalent organic frameworks (COFs) show potential to overcome these problems owing to its good stability and high capacity. Herein, the synthesis and characterization of two π-conjugated COFs, derived from the Schiff-base reaction of 2,4,6-triaminopyrimidne (TM) respectively with 1,4-phthalaldehyde (PA) and 1,3,5-triformylbenzene (TB) by a mechanochemical process are presented. As anode materials for LIBs, the COFs exhibit favorable electrochemical performance with the highest reversible discharge capacities of up to 401.3 and 379.1 mAh g−1 at a high current density (1 A g−1), respectively, and excellent long-term cyclability with 74.8 and 72.7 % capacity retention after 2000 cycles compared to the initial discharge capacities.  相似文献   

12.
Organic carbonyl electrode materials are widely employed for alkali metal-ion secondary batteries in terms of their sustainability, structure designability and abundant resources. As a typical redox-active organic electrode materials, pyrene-4, 5, 9, 10-tetraone (PT) shows high theoretical capacity due to the rich carbonyl active sites. But its electrochemical behavior in secondary batteries still needs further exploration. Herein, PT-based linear polymers (PPTS) is synthesized with thioether bond as bridging group and then employed as an anode material for lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs). As expected, PPTS shows improved conductivity and insolubility in the non-aqueous electrolyte. When used as an anode material for LIBs, PPTS delivers a high reversible specific capacity of 697.1 mAh g−1 at 0.1 A g−1 and good rate performance (335.4 mAh g−1 at 1 A g−1). Moreover, a reversible specific capacity of 205.2 mAh g−1 at 0.05 A g−1 could be obtained as an anode material for SIBs.  相似文献   

13.
The construction of potential electrode materials with wide temperature property for high-energy-density secondary batteries has attracted great interest in recent years. Herein, a hybrid electrode, consisting of a nitrogen-doped carbon/α-MnS/flake graphite composite (α-MnS@N-C/FG), is prepared through a post-sulfurization route. In the α-MnS@N-C/FG composite, α-MnS nanoparticles wrapped by the N−C layer are uniformly embedded onto FG, forming a novel nanofoam structure. The as-obtained α-MnS@N-C/FG shows excellent lithium/sodium storage performance, with a specific capacity of 712 mA h g−1 in the 700th cycle at 1.0 A g−1 or 186.4 mA h g−1 in the 100th cycle at 100 mA g−1 using lithium or sodium foil as the counter electrode, respectively. Moreover, even operated at −20 °C, the α-MnS@N-C/FG can still attain a high specific capacity of 350 mA h g−1 after 50 cycles at 100mA g−1 for LIBs. This exceptional electrochemical response is attributed to the synergetic effect of the smart design of a hybrid nanofoam structure, in which the FG skeleton and N-C coating layer can significantly enhance the conductivity of the whole electrode from bottom to top. Accordingly, the enhanced redox kinetics endow the electrode with pseudocapacitive-dominated electrochemical behavior, leading to fast electrode reactions and robust structural stability in the whole electrode.  相似文献   

14.
The preparation of novel one‐dimensional core–shell Fe/Fe2O3 nanowires as anodes for high‐performance lithium‐ion batteries (LIBs) is reported. The nanowires are prepared in a facile synthetic process in aqueous solution under ambient conditions with subsequent annealing treatment that could tune the capacity for lithium storage. When this hybrid is used as an anode material for LIBs, the outer Fe2O3 shell can act as an electrochemically active material to store and release lithium ions, whereas the highly conductive and inactive Fe core functions as nothing more than an efficient electrical conducting pathway and a remarkable buffer to tolerate volume changes of the electrode materials during the insertion and extraction of lithium ions. The core–shell Fe/Fe2O3 nanowire maintains an excellent reversible capacity of over 767 mA h g?1 at 500 mA g?1 after 200 cycles with a high average Coulombic efficiency of 98.6 %. Even at 2000 mA g?1, a stable capacity as high as 538 mA h g?1 could be obtained. The unique composition and nanostructure of this electrode material contribute to this enhanced electrochemical performance. Due to the ease of large‐scale fabrication and superior electrochemical performance, these hybrid nanowires are promising anode materials for the next generation of high‐performance LIBs.  相似文献   

15.
Biomimetic straw-like bundles of Co-doped Fe2O3 (SCF), with Co2+ incorporated into the lattice of α-Fe2O3, was fabricated through a cost-effective hydrothermal process and used as the anode material for lithium-ion batteries (LIBs). The SCF exhibited ultrahigh initial discharge specific capacity (1760.7 mA h−1 g−1 at 200 mA g−1) and cycling stability (with the capacity retention of 1268.3 mA h−1 g−1 after 350 cycles at 200 mA g−1). In addition, a superior rate capacity of 376.1 mA h−1 g−1 was obtained at a high current density of 4000 mA g−1. The remarkable electrochemical lithium storage of SCF is attributed to the Co-doping, which increases the unit cell volume and affects the whole structure. It makes the Li+ insertion–extraction process more flexible. Meanwhile, the distinctive straw-like bundle structure can accelerate Li ion diffusion and alleviate the huge volume expansion upon cycling.  相似文献   

16.
Silicon monoxide (SiO) is considered as one of the most promising alternative anode materials thanks to its high theoretical capacity, satisfying operating voltage and low cost. However, huge volume change, poor electrical conductivity, and poor cycle performance of SiO dramatically hindered its commercial application. In this work, we report an affordable and simple way for manufacturing carbon-coated SiO−C composites with good electrochemical performance on kilogram scales. Industrial grade SiO was modified by carbon coating using cheap and environment friendly polyvinyl pyrrolidone (PVP) as carbon source. High-resolution transmission electron microscopy (HRTEM) and Raman spectra results show that there is an amorphous carbon coating layer with a thickness of about 40 nm on the surface of SiO. The synthesized SiO−C-650 composite shows great electrochemical performance with a high capacity of 1491 mAh.g−1 at 0.1 C rate and outstanding capacity retention of 67.2 % after 100 cycles. The material also displays an excellent performance with a capacity of 1100 mAh.g−1 at 0.5 C rate. Electrochemical impedance spectroscopy (EIS) results also prove that the carbon coating layer can effectively improve the conductivity of the composite and thus enhance the cycling stability of SiO electrode.  相似文献   

17.
According to the evidence from both theoretical calculations and experimental findings, conjugated ladder polymers containing large π‐conjugated structure, a high number of nitrogen heteroatoms, and a multiring aromatic system, could be an ideal organic anode candidate for lithium‐ion batteries (LIBs). In this report, we demonstrated that the nanostructured polyazaacene analogue poly(1,6‐dihydropyrazino[2,3g]quinoxaline‐2,3,8‐triyl‐7‐(2H)‐ylidene‐7,8‐dimethylidene) (PQL) shows high performance as anode materials in LIBs: high capacity (1750 mAh g?1, 0.05C), good rate performance (303 mAh g?1, 5C), and excellent cycle life (1000 cycles), especially at high temperature of 50 °C. Our results suggest nanostructured conjugated ladder polymers could be alternative electrode materials for the practical application of LIBs.  相似文献   

18.
Flexible lithium‐ion batteries (LIBs) have recently attracted increasing attention with the fast development of bendable electronic systems. Herein, a facile and template‐free solvothermal method is presented for the fabrication of hybrid yolk–shell CoS2 and nitrogen‐doped graphene (NG) sheets. The yolk–shell architecture of CoS2 encapsulated with NG coating is designed for the dual protection of CoS2 to address the structural and interfacial stability concerns facing the CoS2 anode. The as‐prepared composite can be assembled into a film, which can be used as a binder‐free and flexible electrode for LIBs that does not require any carbon black conducting additives or current collectors. When evaluating lithium‐storage properties, such a flexible electrode exhibits a high specific capacity of 992 mAh g?1 in the first reversible discharge capacity at a current rate of 100 mA g?1 and high reversible capacity of 882 mAh g?1 after 150 cycles with excellent capacity retention of 89.91 %. Furthermore, a reversible capacity as high as 655 mAh g?1 is still achieved after 50 cycles even at a high rate of 5 C due to the yolk–shell structure and NG coating, which not only provide short Li‐ion and electron pathways, but also accommodate large volume variation.  相似文献   

19.
Rational designing and controlling of nanostructures is a key factor in realizing appropriate properties required for the high-performance energy fields. In the present study, hollow SnO2@C nanoparticles (NPs) with a mean size of 50 nm have been synthesized in large-scale via a facile hydrothermal approach. The morphology and composition of as-obtained products were studied by various characterized techniques. As an anode material for lithium ion batteries (LIBs), the as-prepared hollow SnO2@C NPs exhibit significant improvement in cycle performances. The discharge capacity of lithium battery is as high as 370 mAh g-1, and the current density is 3910 mA g-1(5 C) after 573 cycles. Furthermore, the capacity recovers up to 1100 mAh g-1 at the rate performances in which the current density is recovered to 156.4 mA g-1(0.2 C). Undoubtedly, sub-100 nm SnO2@C NPs provide significant improvement to the electrochemical performance of LIBs as superior-anode nanomaterials, and this carbon coating strategy can pave the way for developing high-performance LIBs.  相似文献   

20.
Nanostructured tin dioxide (SnO2) has emerged as a promising anode material for lithium-ion batteries (LIBs) due to its high theoretical capacity (1494 mA h g−1) and excellent stability. Unfortunately, the rapid capacity fading and poor electrical conductivity of bulk SnO2 material restrict its practical application. Here, SnO2 nanospheres/reduced graphene oxide nanosheets (SRG) are fabricated through in-situ growth of carbon-coated SnO2 using template-based approach. The nanosheet structure with the external layer of about several nanometers thickness can not only accommodate the volume change of Sn lattice during cycling but also enhance the electrical conductivity effectively. Benefited from such design, the SRG composites could deliver an initial discharge capacity of 1212.3 mA h g−1 at 0.1 A g−1, outstanding cycling performance of 1335.6 mA h g−1 after 500 cycles at 1 A g−1, and superior rate capability of 502.1 mA h g−1 at 5 A g−1 after 10 cycles. Finally, it is believed that this method could provide a versatile and effective process to prepare other metal-oxide/reduced graphene oxide (rGO) 2D nanocomposites.  相似文献   

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