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1.
Chemistry ; 26(4): 853-862, 2020 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-31691394

RESUMO

The Fe-based transition metal oxides are promising anode candidates for lithium storage considering their high specific capacity, low cost, and environmental compatibility. However, the poor electron/ion conductivity and significant volume stress limit their cycle and rate performances. Furthermore, the phenomena of capacity rise and sudden decay for α-Fe2 O3 have appeared in most reports. Here, a uniform micro/nano α-Fe2 O3 nanoaggregate conformably enclosed in an ultrathin N-doped carbon network (denoted as M/N-α-Fe2 O3 @NC) is designed. The M/N porous balls combine the merits of secondary nanoparticles to shorten the Li+ transportation pathways as well as alleviating volume expansion, and primary microballs to stabilize the electrode/electrolyte interface. Furthermore, the ultrathin carbon shell favors fast electron transfer and protects the electrode from electrolyte corrosion. Therefore, the M/N-α-Fe2 O3 @NC electrode delivers an excellent reversible capacity of 901 mA h g-1 with capacity retention up to 94.0 % after 200 cycles at 0.2 A g-1 . Notably, the capacity rise does not happen during cycling. Moreover, the lithium storage mechanism is elucidated by ex situ XRD and HRTEM experiments. It is verified that the reversible phase transformation of α↔γ occurs during the first cycle, whereas only the α-Fe2 O3 phase is reversibly transformed during subsequent cycles. This study offers a simple and scalable strategy for the practical application of high-performance Fe2 O3 electrodes.

2.
ACS Appl Mater Interfaces ; 11(51): 47886-47893, 2019 Dec 26.
Artigo em Inglês | MEDLINE | ID: mdl-31797668

RESUMO

The intrinsic charge-transfer property bears the primary responsibility for the sluggish redox kinetics of the common electrode materials, especially operated at low temperatures. Herein, we report the crafting of homogeneously confined Fe7Se8 nanoparticles with a well-defined graphitic carbon matrix that demonstrate a highly efficient charge-transfer system in a designed natural coral-like structure (cl-Fe7Se8@C). Notably, the intricate architecture as well as highly conductive peculiarity of C concurrently satisfy the demands of achieving fast ionic/electrical conductivities for both Li/Na-ion batteries in a wide temperature range. For example, when cl-Fe7Se8@C is employed as the anode material to assemble full batteries with the cathode of Na3V2(PO4)2O2F (NVPOF), decent capacities of 323.1 and 175.9 mA h g-1 can be acquired at temperatures of 25 and -25 °C, respectively. This work is significant for further developing potential anode materials for advanced energy storage and conversion under low-temperature conditions.

3.
Chemistry ; 25(66): 15173-15181, 2019 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-31544301

RESUMO

Owing to low ion/electron conductivity and large volume change, transitional metal dichalcogenides (TMDs) suffer from inferior cycle stability and rate capability when used as the anode of lithium-ion batteries (LIBs). To overcome these disadvantages, amorphous molybdenum sulfide (MoSx ) nanospheres were prepared and coated with an ultrathin carbon layer through a simple one-pot reaction. Combining X-ray photoelectron spectroscopy (XPS) with theoretical calculations, MoSx was confirmed as having a special chain molecular structure with two forms of S bonding (S2- and S2 2- ), the optimal adsorption sites of Li+ were located at S2 2- . As a result, the MoSx electrode exhibits superior cycle and rate capacities compared with crystalline 2H-MoS2 (e.g., delivering a high capacity of 612.4 mAh g-1 after 500 cycles at 1 A g-1 ). This is mainly attributed to more exposed active S2 2- sites for Li storage, more Li+ transfer pathways for improved ion conductivity, and suppressed electrode structure pulverization of MoSx derived from the inherent chain-like molecular structure. Quantitative charge storage analysis further demonstrates the improved pseudocapacitive contribution of amorphous MoSx induced by fast reaction kinetics. Moreover, the morphology contrast after cycling demonstrates the dispersion of active materials is more uniform for MoSx than 2H-MoS2 , suggesting the MoSx can well accommodate the volume stress of the electrode during discharging. Through regulating the molecular structure, this work provides an effective targeted strategy to overcome the intrinsic issues of TMDs for high-performance LIBs.

4.
Chemistry ; 25(38): 8975-8981, 2019 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-31021424

RESUMO

Lithium-ion batteries (LIBs) are one of the most significant energy storage devices applied in power supply facilities. However, a huge number of spent LIBs would bring harmful resource waste and environmental hazards. In this study, a benign hydrometallurgical method using phytic acid as precipitant is proposed to recover useful metallic Mn ions from spent LiMn2 O4 batteries. Besides Mn-based cathodes, this recovery process is also applicable for other commercial batteries. More importantly, for the first time, the as-obtained manganous complex is employed as a nanofiller in a polyethylene oxide matrix to largely improve Li+ conductivity and transference number. As a result, when applied in all-solid-state lithium batteries, high capacity and outstanding cyclic stability are achieved with capacity retention of 86.4 % after 60 cycles at 0.1 C. The recovery of spent lithium batteries not only has benefits for the environment and resources, but also shows great potential application in all-solid-state lithium batteries, which opens up a costless and efficient circulation pathway for clean and reliable energy storage systems.

5.
Nanoscale ; 11(3): 1304-1312, 2019 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-30603754

RESUMO

In order to develop promising anode materials for lithium-ion batteries (LIBs), a unique nanocomposite abbreviated as G⊥FP@C-NA, in which a carbon-coated FeP nanorod array (FP@C-NA) is vertically grown on a conductive reduced graphene oxide (G) network, has been successfully prepared via a scalable strategy. Benefiting from the distinctive structure, G⊥FP@C-NA exhibits much improved conductivity, structural stability and pseudocapacitance-boosted ultrafast electrochemical kinetics for Li storage. As a result, the G⊥FP@C-NA delivers a high Li-storage capacity (1106 mA h g-1 at 50 mA g-1), outstanding rate capability (565 mA h g-1 at 5000 mA g-1) and long-term cycling stability (1009 mA h g-1 at 500 mA g-1 after 500 cycles and 310 mA h g-1 at 2000 mA g-1 after 2000 cycles) when used as an anode material for LIBs. As expected, this kind of nanoarray structure is attractive and can also be extended to other electrode materials for various energy storage systems.

6.
Nanoscale ; 10(40): 18942-18948, 2018 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-30303226

RESUMO

A three-dimensional hierarchical Ni3Se2 nanorod array (NA) grown in situ on foam Ni is the first to act as a carbon/binder-free electrode of SIBs via a one-step reversible conversion reaction. By a special decomposition-fusion process, the morphology and composition of the NA are regulated to obtain ultrahigh areal capacity, which is three times greater than that reported for other metal selenides.

7.
Dalton Trans ; 47(42): 14932-14937, 2018 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-30252011

RESUMO

Solid-state lithium metal batteries have emerged as a promising alternative to existing liquid Li-ion batteries and can power the future storage market considering their higher energy outputs and better safety. Among various solid electrolytes, polymer electrolytes have received more attention due to their potential advantages, including wide electrochemical windows, ease of processing, low interface impedance and low cost. Polymeric electrolytes based on poly(ethylene oxide) (PEO) as a well-known polymer matrix have been extensively studied because of their highly flexible EO segments in the amorphous phase that can provide channels for lithium ion transport. However, obtaining a PEO-based solid electrolyte with high Li ion conductivity and without sacrificing mechanical strength is still a huge challenge. In this study, polymethylhydrogen-siloxane (PMHS) with low glass transition temperature and good flexibility was blended into the PEO to optimize ion transportation by the solution casting technique. The hybrid electrolyte membrane with 40% PMHS exhibited high ionic conductivity (2.0 × 10-2 S cm-1 at 80 °C), large electrochemical windows (5.2 V), a high degree of flexibility, and thermal stability. When assembling a Li/LiFePO4 battery, a reversible capacity close to 140 mA h g-1 (0.1 C) at 60 °C was delivered. In addition, a cell with this polymer electrolyte exhibits excellent stability. These results demonstrate that solid polymer electrolyte systems are eligible for next-generation high energy density all-solid-state lithium ion batteries.

8.
Chemistry ; 24(38): 9606-9611, 2018 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-29633384

RESUMO

MnO is a promising high-capacity anode material for lithium-ion batteries (LIBs), but pristine material suffers short cycle life and poor rate capability, thus hindering the practical application. In this work, a new type of porous MnO microballs stringed with N-doped porous carbon (3DHB-MnO@NC) with a well-connected hierarchical three-dimensional network structure was prepared by the facile self-template method. The 3DHB-MnO@NC electrode can effectively promote the ion/electron transfer and buffer the large volume change of electrode during the electrochemical reaction. As the anode for LIBs, the 3DHB-MnO@NC possesses outstanding cycling performance (1247.7 mA h g-1 after 90 cycles at 200 mA g-1 ) and good rate capabilities (949.6 mA h g-1 after 450 cycles at 1000 mA g-1 ). The facile self-template method of the prepared 3DHB-MnO@NC composite paves a new way for practical applications of MnO in high performance LIBs.

9.
Chemistry ; 24(26): 6798-6803, 2018 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-29575314

RESUMO

A new hexadecahedron assembled by core-shell CoS2 particles@N-doped carbon (CoS2 @NCH) is prepared successfully through the self-templating method. The CoS2 @NCH hybrid electrode delivers a high lithium-storage capacity of 778 mA h g-1 after 1000 cycles at a high current density of 1 A g-1 , which is the longest cycle lifespan among the reported CoS2 anode materials in lithium-ion batteries. Furthermore, the CoS2 @NCH hybrid electrode shows excellent rate capability with a discharge capacity of 220 mA h g-1 at an extremely high current density of 20 A g-1 , and a charge capacity of 649 mA h g-1 is restored upon returning the current density back to 2 A g-1 . The superior performance is attributed to the unique construction of CoS2 @NCH. The N-doped interconnected porous carbon shells form highly conductive skeletons for quick electron transfer and prevent the electrode from collapsing. Moreover, the porous characteristic of the materials plays a key role: as some effective channels, the mesopores on the porous carbon shells provide greater access for lithium, and the mesopores derived from the particle interspace enables the complete immersion of the electrodes in electrolyte, which alleviates the volume expansion and ensures the integrity of the electrode. In addition, the nanosized CoS2 particles, which shorten the ion-transport path and provide extra electroactive sites, also improve the reaction kinetics.

10.
ACS Appl Mater Interfaces ; 10(1): 509-516, 2018 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-29243916

RESUMO

A three-layered cathode structure was designed to minimize the shuttle effect of polysulfides and improve active material utilization. The three-layered configuration was fabricated by directly dropping pure sulfur composite slurry into multifunctional dual-barrier layers consisting of a self-standing TiO2/C interlayer and a very thin acetylene black layer (0.35 mg cm-2). In consequence, a decent discharge capacity of 963 mA h g-1 was acquired after 100 cycles at 0.1 C. With cycling at 0.1, 0.2, 0.5, 1, and 2 C, the cells displayed excellent reversible capacities of 1203, 1145, 1035, 934, and 820 mA h g-1, respectively. Furthermore, the cells still delivered a satisfactory discharge capacity of 799 mA h g-1 after 300 cycles at 0.5 C. The light mass of the three-layered configuration guarantees that the energy density is effectively improved, considering the overall mass of the cathode. The energy density (603 W h kg-1 after 100 cycles) was at a high level compared with those of the reported ones. Therefore, it is believed that the synergistic design for the three-layered cathode structure, which combines the mass-produced layer-by-layer structure, provides a novel protocol to the practical application of lithium-sulfur batteries.

11.
Chemistry ; 23(40): 9666-9673, 2017 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-28508401

RESUMO

In this work, oxygen-deficient anatase TiO2 nanosheets (A-TiO2-x NSs) are proposed as a substrate to improve the electrochemical properties of sulfur electrodes for lithium-sulfur (Li-S) batteries. The A-TiO2-x NSs are prepared by partly reducing pristine TiO2 nanosheets (A-TiO2 NSs) in NaBH4 solution. With some oxygen vacancies on the surface of the TiO2 nanosheets, A-TiO2-x NSs not only promote electronic transfer, but also act as more effective polysulfide reservoirs to minimize the dissolution of lithium polysulfides (LiPSs) than the A-TiO2 NSs control. Hence, upon utilization as modifiers for cathodes of Li-S batteries, the A-TiO2-x NSs-modified sulfur (A-TiO2-x NSs-S) cathode exhibits a higher reversible specific capacity and greater cycling performance and rate capability than the A-TiO2 NSs-modified one (A-TiO2 NSs-S). For example, A-TiO2-x NSs-S delivers an initial specific capacity of 1277.1 mAh g-1 at 0.1 C and maintains a stable Coulombic efficiency of approximately 99.2 % after the first five cycles; these values are higher than those of 997.3 mAh g-1 and around 96.7 %, respectively, for A-TiO2 NSs-S. The enhanced electrochemical properties of the A-TiO2-x NSs-S cathode can be ascribed mainly to the more effective adsorption of dissolvable and diffused LiPSs by the oxygen vacancies. Therefore, utilization of the structure of oxygen vacancies in Li-S batteries demonstrates great prospects for practical application.

12.
Chemistry ; 23(36): 8712-8718, 2017 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-28452106

RESUMO

Bimetallic transition-metal oxides, which exhibit superior electrochemical properties compared with pristine single-metal oxides, have recently become a topic of significant research interest for applications in lithium-ion batteries (LIBs). Herein, we report a simple and scalable electrospinning method to synthesize porous CoTiO3 nanofibers as the precursor for nanostructured bimetallic transition-metal oxides formed electrochemically in situ. This strategy ensures uniform mixing and perfect contact between two constituent transition-metal oxides during the lithiation/delithiation process. Furthermore, CoTiO3 nanofibers based on ultrafine CoTiO3 nanocrystals are interconnected to form a nano/microstructured 3D network, which ensures the high stability of the in situ formed structure composed of bimetallic transition-metal oxides, and also fast ion/electron transfer and electrolyte penetration into the electrode. Electrochemical measurements revealed the excellent lithium storage (647 mAh g-1 at 0.1 Ag-1 ) and retention properties (600 mAh g-1 at 1 Ag-1 after 1200 cycles) of the CoO/TiO2 electrode. Moreover, the electrochemical reaction mechanism was explored by using ex situ X-ray photoelectric spectroscopy and cyclic voltammetry tests, which confirmed the two-phase reaction processes in the electrodes. These results clearly validate the potential of CoTiO3 with a unique nano/microstructured morphology as the precursor for a bimetallic transition-metal oxide for use as the anode material for long-life LIBs.

13.
ACS Appl Mater Interfaces ; 9(12): 10708-10716, 2017 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-28263060

RESUMO

Marcasite (m-FeS2) exhibits higher electronic conductivity than that of pyrite (p-FeS2) because of its lower semiconducting gap (0.4 vs 0.7 eV). Meanwhile, as demonstrates stronger Fe-S bonds and less S-S interactions, the m-FeS2 seems to be a better choice for electrode materials compared to p-FeS2. However, the m-FeS2 has been seldom studied due to its sophisticated synthetic methods until now. Herein, a hierarchical m-FeS2 and carbon nanofibers composite (m-FeS2/CNFs) with grape-cluster structure was designed and successfully prepared by a straightforward hydrothermal method. When evaluated as an electrode material for lithium ion batteries, the m-FeS2/CNFs exhibited superior lithium storage properties with a high reversible capacity of 1399.5 mAh g-1 after 100 cycles at 100 mA g-1 and good rate capability of 782.2 mAh g-1 up to 10 A g-1. The Li-storage mechanism for the lithiation/delithiation processes of m-FeS2/CNFs was systematically investigated by ex situ powder X-ray diffraction patterns and scanning electron microscopy. Interestingly, the hierarchical m-FeS2 microspheres assembled by small FeS2 nanoparticles in the m-FeS2/CNFs composite converted into a mimosa with leaves open shape during Li+ insertion process and vice versa. Accordingly, a "CNFs accelerated decrystallization-recrystallization" mechanism was proposed to explain such morphology variations and the decent electrochemical performance of m-FeS2/CNFs.

14.
ACS Appl Mater Interfaces ; 9(14): 12518-12527, 2017 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-28345854

RESUMO

In this work, a flexible and self-supporting P-doped carbon cloth (FPCC), which is composed of interwoven mesh of hollow microtubules with porous carbon walls, is prepared via a vacuum-sealed doping technology by employing the commercially available cotton cloth as sustainable and scalable raw material. When directly used as binder-free anode for sodium-ion batteries, the as-prepared FPCC delivers superior Na-storage properties in terms of specific capacity up to 242.4 mA h g-1, high initial Coulombic efficiency of ∼72%, excellent rate capabilities (e.g., 123.1 mA h g-1 at a high current of 1 A g-1), and long-term cycle life (e.g., ∼88% capacity retention after even 600 cycles). All these electrochemical data are better than the undoped carbon cloth control, demonstrating the significance of P-doping to enhance the Na-storage properties of cotton-derived carbon anode. Furthermore, the technologies of electrochemical impedance spectroscopy and galvanostatic intermittent titration technique are implemented to disclose the decrease of charge transfer resistance and improvement of Na-migration kinetics, respectively.

15.
ACS Appl Mater Interfaces ; 8(46): 31722-31728, 2016 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-27805360

RESUMO

In this work, carbon-free, porous, and micro/nanostructural Zn2GeO4 nanofibers (p-ZGONFs) have been prepared via a dissolution-recrystallization-assisted electrospinning technology. The successful electrospinning to fabricate the uniform p-ZGONFs mainly benefits from the preparation of completely dissolved solution, which avoids the sedimentation of common Ge-containing solid-state precursors. Electrochemical tests demonstrate that the as-prepared p-ZGONFs exhibit superior Li-storage properties in terms of high initial reversible capacity of 1075.6 mA h g-1, outstanding cycling stability (no capacity decay after 130 cycles at 0.2 A g-1), and excellent high-rate capabilities (e.g., still delivering a capacity of 384.7 mA h g-1 at a very high current density of 10 A g-1) when used as anode materials for lithium ion batteries (LIBs). All these Li-storage properties are much better than those of Zn2GeO4 nanorods prepared by a hydrothermal process. The much enhanced Li-storage properties should be attributed to its distinctive structural characteristics including the carbon-free composition, plentiful pores, and macro/nanostructures. Carbon-free composition promises its high theoretical Li-storage capacity, and plentiful pores cannot only accommodate the volumetric variations during the successive lithiation/delithiation but can also serve as the electrolyte reservoirs to facilitate Li interaction with electrode materials.

16.
ACS Appl Mater Interfaces ; 8(42): 28689-28699, 2016 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-27731632

RESUMO

The synergistic design of cathode region was conducted to minimize the shuttle effect of polysulfides and decrease the loading of inactive components in order to acquire high-energy-density lithium-sulfur (Li-S) batteries. The well-designed cathode region presented two special characteristics: one was the intertwined nanofibers interlayer based on ultrafine TiO2 nanocrystal uniformly embedded within N-doping porous carbon; the other was the lightweight and three-dimensional current collector of fibrous cellulose paper coated by reduced graphene oxide. In consequence, the decent reversible capacity of 874.8 mA h g-1 was acquired at 0.1 C with a capacity retention of 91.83% after 100 cycles. Besides, the satisfactory capacity of 670 mA h g-1 was delivered after 300 cycles at 1 C with the small decay rate of only 0.08%. Because of higher capacity and lower loading of inactive component in cathode region, the energy density of cell increased more than five times compared with unmodified cell. Moreover, to further enhance the energy density, the high-sulfur-loading electrode was fabricated. A good areal capacity of 4.27 mA h cm-2 was retained for the cell with the active material of 4 mg cm-2 and the cycle stability was also well-maintained. In addition, due to the flexibility of interlayer and current collector, Li-S full cell (in pouch cell format) was easily curved. Therefore, the synergistic design for cathode region, which combines the flexible and mass-produced interlayer and current collector together, provides an effective access to Li-S batteries with high energy density and flexibility for practical application.

17.
ACS Appl Mater Interfaces ; 8(25): 16108-15, 2016 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-27285289

RESUMO

In this work, the lightweight and scalable organic macromolecule graphitic carbon nitride (g-C3N4) with enriched polysulfide adsorption sites of pyridinic-N was introduced to achieve the effective functionalization of separator at the molecular level. This simple method overcomes the difficulty of low doping content as well as the existence of an uncontrolled form of nitrogen heteroatom in the final product. Besides the conventional pyridinic-N-Li bond formed in the vacancies of g-C3N4, the C-S bond was interestingly observed between g-C3N4 and Li2S, which endowed g-C3N4 with an inherent adsorption capacity for polysulfides. In addition, the microsized g-C3N4 provided the coating layer with good mechanical strength to guarantee its restriction function for polysulfides during long cycling. As a result, an excellent reversible capacity of 840 mA h g(-1) was retained at 0.5 C after 400 cycles for a pure sulfur electrode, much better than that of the cell with an innocent carbon-coated separator. Even at a current density of 1 C, the cell still delivered a stable capacity of 732.7 mA h g(-1) after 500 cycles. Moreover, when further increasing the sulfur loading to 5 mg cm(-2), an excellent specific capacity of 1134.7 mA h g(-1) was acquired with the stable cycle stability, ensuring a high areal capacity of 5.11 mA h cm(-2). Besides the intrinsic adsorption ability for polysulfides, g-C3N4 is nontoxic and mass produced. Therefore, a scalable separator decorated with g-C3N4 and a commercial sulfur cathode promises high energy density for the practical application of Li-S batteries.

18.
ChemSusChem ; 9(12): 1483-9, 2016 06 22.
Artigo em Inglês | MEDLINE | ID: mdl-27219476

RESUMO

Inspired by the preparation of the hierarchically-porous carbon (HPC) derived from metal organic frameworks (MOFs) for energy storage, in this work, a simple iron-based metal- organic complex (MOC), which was simpler and cheaper compared with the MOF, was selected to achieve versatile energy storage. The intertwined 1 D nanospindles and enriched-oxygen doping of the HPC was obtained after one-step carbonization of the MOC. When employed in lithium-ion batteries, the HPC exhibited reversible capacity of 778 mA h g(-1) after 60 cycles at 50 mA g(-1) . Moreover, the HPC maintained a capacity of 188 mA h g(-1) after 400 cycles at 100 mA g(-1) as the anode material in a sodium-ion battery. In addition, the HPC served as the cathode matrix for evaluation of a lithium-sulfur battery. The general preparation process of the HPC is commercial, which is responsible for the large-scale production for its practical application.


Assuntos
Carbono/química , Fontes de Energia Elétrica , Ferro/química , Compostos Organometálicos/química , Lítio/química , Porosidade , Enxofre/química , Temperatura Ambiente
19.
ACS Appl Mater Interfaces ; 8(6): 4233-41, 2016 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-26815316

RESUMO

In this paper, gelatin as a natural biomass was selected to successfully prepare an oxygen-enriched carbon with layered sedimentary rocks structure, which exhibited ultrahigh-rate performance and excellent cycling stability as supercapacitors. The specific capacitance reached 272.6 F g(-1) at 1 A g(-1) and still retained 197.0 F g(-1) even at 100 A g(-1) (with high capacitance retention of 72.3%). The outstanding electrochemical performance resulted from the special layered structure with large surface area (827.8 m(2) g(-1)) and high content of oxygen (16.215 wt %), which effectively realized the synergistic effects of the electrical double-layer capacitance and pseudocapacitance. Moreover, it delivered an energy density of 25.3 Wh kg(-1) even with a high power density of 34.7 kW kg(-1) and ultralong cycling stability (with no capacitance decay even over 10,000 cycles at 2 A g(-1)) in a symmetric supercapacitor, which are highly desirable for their practical application in energy storage devices and conversion.


Assuntos
Carbono/química , Capacitância Elétrica , Sedimentos Geológicos/química , Oxigênio/química
20.
ACS Appl Mater Interfaces ; 7(50): 27959-67, 2015 Dec 23.
Artigo em Inglês | MEDLINE | ID: mdl-26619747

RESUMO

In this work, the chemical interaction of cathode and lithium polysulfides (LiPSs), which is a more targeted approach for completely preventing the shuttle of LiPSs in lithium-sulfur (Li-S) batteries, has been established on the electrode level. Through simply posttreating the ordinary sulfur cathode in atmospheric environment just for several minutes, the Au nanoparticles (Au NPs) were well-decorated on/in the surface and pores of the electrode composed of commercial acetylene black (CB) and sulfur powder. The Au NPs can covalently stabilize the sulfur/LiPSs, which is advantageous for restricting the shuttle effect. Moreover, the LiPSs reservoirs of Au NPs with high conductivity can significantly control the deposition of the trapped LiPSs, contributing to the uniform distribution of sulfur species upon charging/discharging. The slight modification of the cathode with <3 wt % Au NPs has favorably prospered the cycle capacity and stability of Li-S batteries. Moreover, this cathode exhibited an excellent anti-self-discharge ability. The slight decoration for the ordinary electrode, which can be easily accessed in the industrial process, provides a facile strategy for improving the performance of commercial carbon-based Li-S batteries toward practical application.

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