| 1. |
- Haridas, Anupriya K., et al.
(författare)
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An Electrospun Core–Shell Nanofiber Web as a High-Performance Cathode for Iron Disulfide-Based Rechargeable Lithium Batteries
- 2018
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Ingår i: ChemSusChem. - : Wiley. - 1864-5631 .- 1864-564X. ; 11:20, s. 3625-3630
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Tidskriftsartikel (refereegranskat)abstract
- FeS2/C core–shell nanofiber webs were synthesized for the first time by a unique synthesis strategy that couples electrospinning and carbon coating of the nanofibers with sucrose. The design of the one-dimensional core–shell morphology was found to be greatly beneficial for accommodating the volume changes encountered during cycling, to induce shorter lithium ion diffusion pathways in the electrode, and to prevent sulfur dissolution during cycling. A high discharge capacity of 545 mAh g−1 was retained after 500 cycles at 1 C, exhibiting excellent stable cycling performance with 98.8 % capacity retention at the last cycle. High specific capacities of 854 mAh g−1, 518 mAh g−1, and 208 mAh g−1 were obtained at 0.1 C, 1 C, and 10 C rates, respectively, demonstrating the exceptional rate capability of this nanofiber web cathode.
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| 2. |
- Haridas, Anupriya K., et al.
(författare)
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Boosting High Energy Density Lithium-Ion Storage via the Rational Design of an FeS-Incorporated Sulfurized Polyacrylonitrile Fiber Hybrid Cathode
- 2019
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Ingår i: ACS Applied Materials & Interfaces. - : American Chemical Society (ACS). - 1944-8252 .- 1944-8244. ; 11:33, s. 29924-29933
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Tidskriftsartikel (refereegranskat)abstract
- In order to satisfy the escalating energy demands, it is inevitable to improve the energy density of current Li-ion batteries. As the development of high-capacity cathode materials is of paramount significance compared to anode materials, here we have designed for the first time a unique synergistic hybrid cathode material with enhanced specific capacity, incorporating cost-effective iron sulfide (FeS) nanoparticles in a sulfurized polyacrylonitrile (SPAN) nanofiber matrix through a rational in situ synthesis strategy. Previous reports on FeS cathodes are scarce and consist of an amorphous carbon matrix to accommodate the volume changes encountered during the cycling process. However, this inactive buffering matrix eventually increases the weight of the cell, reducing the overall energy density. By the rational design of this hybrid composite cathode, we ensure that the presence of covalently bonded sulfur in SPAN guarantees high sulfur utilization, while effectively buffering the volume changes in FeS. Meanwhile, FeS can compensate for the conductivity issues in the SPAN, thereby realizing a synergistically driven dual-active cathode material improving the overall energy density of the composite. Simultaneous in situ generation of FeS nanoparticles within the SPAN fiber matrix was carried out via electrospinning followed by a one-step heating procedure. The developed hybrid cathode material displays enhanced lithium-ion storage, retaining 688.6 mA h g(FeS@SPAN composite)-1 at the end of 500 cycles at 1 A g-1 even within a narrow voltage range of 1-3.0 V. A high discharge energy density > 900 W h kg(FeS@SPAN composite)-1, much higher than the theoretical energy density of the commercial LiCoO2 cathode, was also achieved, revealing the promising prospects of this hybrid cathode material for high energy density applications.
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| 3. |
- Haridas, Anupriya K., et al.
(författare)
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A flexible and free-standing FeS/sulfurized polyacrylonitrile hybrid anode material for high-rate sodium-ion storage
- 2020
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Ingår i: Chemical Engineering Journal. - : Elsevier BV. - 1385-8947. ; 385:1 April
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Tidskriftsartikel (refereegranskat)abstract
- Sodium-ion based energy storage systems have attracted extensive attention due to the similarities in the mechanism of operation with lithium-ion batteries along with the additional benefit of low cost and high abundance of sodium resources. Iron sulfide-based electrodes that operate via conversion mechanism have shown ample potential for high energy sodium-ion storage. However, the problems related with tremendous volume changes and the dissolution of sodium polysulfides in the electrolyte deteriorate the cycle life and limit their application in sodium-ion batteries (SIBs). Herein, a hybrid anode material, FeS/SPAN-HNF, with iron sulfide (FeS) nanoparticles decorated in a sulfurized polyacrylonitrile (SPAN) fiber matrix is demonstrated as flexible and free-standing anode material for high-rate SIBs. Unlike previous strategies in which FeS is encapsulated in an electrochemically inactive carbon matrix, this study utilizes SPAN, an electrochemically active material, as a dual functional matrix that can efficiently buffer volume expansion and sulfur dissolution of FeS nanoparticles as well as provide significant capacity improvement. The as-designed electrode is self-standing and flexible, without current collectors, binders or additional conductive agents, thus rendering enhanced practical capacity and energy density. This electrode showed a high reversible capacity of 782.8 mAh g−1 at 200 mA g−1 with excellent high rate capability, maintaining 327.5 mAh g−1 after 500 cycles at 5 A g−1, emphasizing promising prospects for the development of flexible and high energy density SIBs.
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| 4. |
- Lim, Du Hyun, 1983, et al.
(författare)
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Tailor-Made Electrospun Multilayer Composite Polymer Electrolytes for High-Performance Lithium Polymer Batteries
- 2018
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Ingår i: Journal of Nanoscience and Nanotechnology. - : American Scientific Publishers. - 1533-4880. ; 18:9, s. 6499-6505
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Tidskriftsartikel (refereegranskat)abstract
- A novel tailor-made multilayer composite polymer electrolyte, consisting of two outer layers of electrospun polyacrylonitrile (PAN) and one inner layer of poly(vinyl acetate) (PVAc)/poly(methyl methacrylate) (PMMA)/poly(ethylene oxide) (PEO) fibrous membrane, was prepared using continuous electrospinning. These membranes, which are made up of fibers with diameters in the nanometer range, were stacked in layers to produce interconnected pores that result in a high porosity. Gel polymer electrolytes (GPEs) were prepared by entrapping a liquid electrolyte (1 M LiPF6 in ethylene carbonate/dimethyl carbonate) in the membranes. The composite membranes exhibited a high electrolyte uptake of 450-510%, coupled with an improved room temperature ionic conductivity of up to 4.72 mS cm(-1) and a high electrochemical stability of 4.6 V versus Li/Li+. Electrochemical investigations of a composite membrane of PAN-PVAc-PAN, with a LiFePO4 cathode synthesized in-house, showed a high initial discharge capacity of 145 mAh g(-1), which corresponds to 85% utilization of the active material, and displayed stable cycle performance.
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