| 1. |
- Siriwardena, D. P., et al.
(författare)
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Probing the effect of Mg doping on triclinic Na2Mn3O7 transition metal oxide as cathode material for sodium-ion batteries
- 2021
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Ingår i: Electrochimica Acta. - : Elsevier Ltd. - 0013-4686 .- 1873-3859. ; 394
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Tidskriftsartikel (refereegranskat)abstract
- Triclinic Na2Mn3O7 has been identified as a promising material for high-capacity sodium-ion batteries. However, the knowledge on the effect of doping of metal ions and structural transformations of Na2Mn3O7 during dis(charge) is limited. Integration of alkali metal-ions, specially Mg2+ can enhance the electrochemical properties in transition metal oxides. Herein, a series of Mg2+ doped triclinic Na2Mn3O7 cathode materials was explored for the first time. Electrochemical analysis revealed that Mg2+ improves specific capacities, and rate capabilities. Ex situ X-ray diffraction (XRD) and Galvanostatic charge discharge cycling (GCD) showed that the triclinic phase reversibly converts into two monoclinic phases at high Na+ insertion levels. Na+ extraction at high potentials is supported by another biphasic region which converts to a major triclinic phase at the end of the charge. GCD, cyclic voltammetry (CV) and ex situ X-ray absorption spectroscopy (XAS) documented that the capacity mainly evolved through a Mn4+/3+ redox couple and a reversible O2-/n− redox reaction. CV and Galvanostatic intermittent titration techniques (GITT) showed that Mg2+ reduces the Na+-vacancy ordering and improves the Na+ diffusion. The 2 mol.% Mg-doped material exhibited a high specific capacity of 143 mAh/g after 30 cycles and a rate capability of 93 mAh/g (at 500 mA/g). GCD analysis demonstrated that O2-/n− redox is remarkably stable up to at least 90 cycles. Full cells made using the 0.5 mol.% Mg-doped material displayed a promising discharge specific capacity of 80 mAh/g. The effects of cation doping into the complex crystal structures, phase transformations during Na+ de(intercalation) and the importance of O2-/n− redox for achieving high capacities were uncovered. The findings of this work will guide the design of novel cathode materials for sodium-ion batteries. © 2021
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| 2. |
- Dongale, T. D., et al.
(författare)
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Bifunctional nanoparticulated nickel ferrite thin films : Resistive memory and aqueous battery applications
- 2021
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Ingår i: Materials & design. - : Elsevier Ltd. - 0264-1275 .- 1873-4197. ; 201
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Tidskriftsartikel (refereegranskat)abstract
- Herein, excellent non-volatile memory and aqueous battery properties of solution-processable nickel ferrite (NFO) nanomaterial were demonstrated. In the case of non-volatile memory property, the device operates on ±2 V resistive switching voltage and shows double valued charge-magnetic flux characteristics. Excellent endurance (103) and retention (104 s) non-volatile memory properties with a good memory window (103) were observed for NFO memristive device. The conduction and resistive switching mechanisms based on experimental data are provided. Furthermore, the present work investigates the electrochemical performance of the NFO thin film electrode in the different electrolytes (viz. Na2SO4, Li2SO4, and Na2SO4: Li2SO4). It was revealed that the NFO thin film shows improved electrochemical performance in Na2SO4 electrolyte with a high specific capacity of 18.56 mAh/g at 1 mA/cm2 current density. The electrochemical impedance spectroscopic results reveal that the NFO thin film electrode shows low series and charge transfer resistance values for Na2SO4 electrolyte than other electrolytes. The diffusion coefficient of different ions (DNa+, DLi+ and DNa+:Li+) were found to be 9.975 × 10−10 cm2 s−1, 3.292 × 10−11 cm2 s−1, 2 × 10−10 cm2 s−1, respectively. A high diffusion coefficient was found for Na+ ions, indicating rapid Na+ transport with NFO thin-film electrodes © 2021 The Authors
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| 3. |
- Erickson, C. M., et al.
(författare)
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KLOTHO heterozygosity attenuates APOE4-related amyloid burden in preclinical AD
- 2019
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Ingår i: Neurology. - : Ovid Technologies (Wolters Kluwer Health). - 0028-3878 .- 1526-632X. ; 92:16
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Tidskriftsartikel (refereegranskat)abstract
- Objective To examine whether the KLOTHO gene variant KL-VS attenuates APOE4-associated beta-amyloid (A beta) accumulation in a late-middle-aged cohort enriched with Alzheimer disease (AD) risk factors. Three hundred nine late-middle-aged adults from the Wisconsin Registry for Alzheimer's Prevention and the Wisconsin Alzheimer's Disease Research Center were genotyped to determine KL-VS and APOE4 status and underwent CSF sampling (n = 238) and/or 11C-Pittsburgh compound B (PiB)-PET imaging (n = 183). Covariate-adjusted regression analyses were used to investigate whether APOE4 exerted expected effects on A beta burden. Follow-up regression analyses stratified by KL-VS genotype (i.e., noncarrier vs heterozygous; there were no homozygous individuals) evaluated whether the influence of APOE4 on A beta was different among KL-VS heterozygotes compared to noncarriers. APOE4 carriers exhibited greater A beta burden than APOE4-negative participants. This effect was stronger in CSF (t = -5.12, p < 0.001) compared with PiB-PET (t = 3.93, p < 0.001). In the stratified analyses, this APOE4 effect on A beta load was recapitulated among KL-VS noncarriers (CSF: t = -5.09, p < 0.001; PiB-PET: t = 3.77, p < 0.001). In contrast, among KL-VS heterozygotes, APOE4-positive individuals did not exhibit higher A beta burden than APOE4-negative individuals (CSF: t = -1.03, p = 0.308; PiB-PET: t = 0.92, p = 0.363). These differential APOE4 effects remained after KL-VS heterozygotes and noncarriers were matched on age and sex. In a cohort of at-risk late-middle-aged adults, KL-VS heterozygosity was associated with an abatement of APOE4-associated A beta aggregation, suggesting KL-VS heterozygosity confers protections against APOE4-linked pathways to disease onset in AD.
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| 4. |
- Pham, H. D., et al.
(författare)
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Large interspaced layered potassium niobate nanosheet arrays as an ultrastable anode for potassium ion capacitor
- 2021
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Ingår i: Energy Storage Materials. - : Elsevier B.V.. - 2405-8289 .- 2405-8297. ; 34, s. 475-482
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Tidskriftsartikel (refereegranskat)abstract
- Potassium-ion battery (KIB) is a promising technology for large-scale energy storage applications due to their low cost, theoretically high energy density and abundant resources. However, the development of KIBs is hindered by the sluggish K+ transport kinetics and the structural instability of the electrode materials during K+ intercalation/de-intercalation. In the present investigation, we have designed a potassium-ion capacitor (KIC) using layered potassium niobate (K4Nb6O17, KNO) nanosheet arrays as anode and orange-peel derived activated carbons (OPAC) as fast capacitive cathode materials. The systematic electrochemical analysis with the ex-situ characterizations demonstrates that KNO-anode exhibits highly stable layered structure with excellent reversibility during K+ insertion/de-insertion. After optimization, the fabricated KNO//OPAC delivers both a high energy density of 116 Wh/kg and high power density of 10,808 W/kg, which is significantly higher than other similar hybrid devices. The cell also displays long term cycling stability over 5000 cycles, with 87 % of capacity retention. This study highlights the utilization of layered nanosheet arrays of niobates to achieve superior K-storage for KICs, paving the way towards the development of high-performance anodes for post lithium-ion batteries. © 2020
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| 5. |
- Annamalai, P. K., et al.
(författare)
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An Overview of Cellulose-Based Nanogenerators
- 2021
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Ingår i: Advanced Materials Technologies. - : John Wiley and Sons Inc. - 2365-709X. ; 6:3
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Tidskriftsartikel (refereegranskat)abstract
- Developing nanogenerators (NGs) is achieved by exploiting the piezoelectric, triboelectric, and pyroelectric effects of both organic and inorganic materials. Many exhibit beneficial electrical properties (dielectric, conductive, or insulating) or have surfaces that are polarizable upon friction or physical contact. Recently, biomass-derived materials and recycled materials, whose electrical activity can be induced, are explored for application in the design of more sustainable, cost-effective, biodegradable, disposable NGs, and have demonstrated a wide range of output (microenergy) power densities. Among them, cellulose, the most abundant biopolymer, is found to offer excellent opportunities for designing and manufacturing NGs with multifunctional capacities. Cellulose can be derived into varied forms with multifunctionalities and physical morphologies. This account provides an overview of how cellulose is utilized in creating NGs based on piezoelectric, triboelectric, and pyroelectric effects. Because the mechanical properties of cellulose are tunable, current research trends on NGs originate with the triboelectric effect. The discussion here focuses on design, fabrication methods, achievable electrical power output, and combinations with other materials and devices. Challenges in efficient fabrication and consistent power densities, and opportunities for integrating different technologies and developing more sustainable (in terms of economic, environmental, and ecological) nature–human–machine interfacial devices are also discussed. © 2021 Wiley-VCH GmbH
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| 6. |
- Aziz, S. K. T., et al.
(författare)
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Bimetallic Phosphides for Hybrid Supercapacitors
- 2021
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Ingår i: The Journal of Physical Chemistry Letters. - : American Chemical Society. - 1948-7185. ; 12, s. 5138-5149
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Tidskriftsartikel (refereegranskat)abstract
- Supercapacitors (SCs) are considered promising energy storage systems because of their high power output and long-term cycling stability; however, they usually exhibit poor energy density. The hybrid supercapacitor (HSC) is an emerging concept in which two dissimilar electrodes with different charge storage mechanisms are paired to deliver high energy without sacrificing power output. This Perspective highlights the features of transition-metal phosphides (TMPs) as the positive electrode in HSCs. In particular, bimetallic nickel cobalt phosphide (NiCoP) with multiple redox sites, excellent electrochemical reversibility, and stability is discussed. We outline how the rational heterostructures, elemental variations, and nanocomposite morphologies tune the electrochemical properties of NiCoP as the positive electrode in HSCs. The Perspective further sheds light on NiCoP-based composites that help in improving the overall performance of HSCs in terms of energy density and cycling stability. The key scientific challenges and perspectives on building efficient and stable HSCs for future applications are discussed. © 2021 American Chemical Society. All rights reserved.
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| 7. |
- Chodankar, N. R., et al.
(författare)
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Solution-free self-assembled growth of ordered tricopper phosphide for efficient and stable hybrid supercapacitor
- 2021
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Ingår i: Energy Storage Materials. - : Elsevier B.V.. - 2405-8289 .- 2405-8297. ; 39, s. 194-202
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Tidskriftsartikel (refereegranskat)abstract
- Herein, a solution-free dry strategy for the growth of self-assembled ordered tricopper phosphide (Cu3P) nanorod arrays is developed and the product is employed as a high-energy, stable positive electrode for a solid-state hybrid supercapacitor (HSC). The ordered Cu3P nanorod arrays grown on the copper foam deliver an excellent specific capacity of 664 mA h/g with an energy efficiency of 88% at 6 A/g and an ultra-long cycling stability over 15,000 continuous charge–discharge cycles. These electrochemical features are attributed to the ordered growth of the Cu3P nanorod arrays, which offers a large number of accessible electroactive sites, a reduced number of ion transfer paths, and reversible redox activity. The potential of the Cu3P nanorod arrays is further explored by engineering solid-state HSCs in which the nanorods are paired with an activated carbon-based negative electrode. The constructed cell is shown to convey a specific energy of 76.85 Wh/kg at a specific power of 1,125 W/kg and an 88% capacitance retention over 15,000 cycles. Moreover, the superior energy storing and delivery capacity of the cell is demonstrated by an energy efficiency of around 65%. The versatile solution-free dry strategies developed here pave the way towards engineering a range of electrode materials for next-generation energy storage systems. © 2021 Elsevier B.V.
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| 8. |
- Goel, P., et al.
(författare)
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Perovskite materials as superior and powerful platforms for energy conversion and storage applications
- 2021
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Ingår i: Nano Energy. - : Elsevier Ltd. - 2211-2855 .- 2211-3282. ; 80
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Tidskriftsartikel (refereegranskat)abstract
- In order to meet the continuously growing demand for clean energy, a plethora of advanced materials have been exploited for energy storage applications. Among these materials, perovskites belong to a relatively new family of compounds with the structural formula of ABX3. These compounds exhibit a variety of electrical, optical, and electronic properties to adopt them for a variety of energy conversion and storage applications. The present review highlights the multifaceted nature of perovskite materials by covering a brief background, common crystallographic structures, and the importance of doping with different elements. Our discussion is extended further on the strategic energy applications of perovskites in modern devices such as fuel cells, lithium batteries, supercapacitors, LEDs, and solar cells. © 2020 Elsevier Ltd
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| 9. |
- Horn, M. R., et al.
(författare)
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Polyoxometalates (POMs) : From electroactive clusters to energy materials
- 2021
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Ingår i: Energy & Environmental Science. - : Royal Society of Chemistry. - 1754-5692 .- 1754-5706. ; 14:4, s. 1652-1700
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Tidskriftsartikel (refereegranskat)abstract
- Polyoxometalates (POMs) represent a class of nanomaterials, which hold enormous promise for a range of energy-related applications. Their promise is owing to their "special"structure that gives POMs a truly unique ability to control redox reactions in energy conversion and storage. One such amazing capability is their large number of redox active sites that arises from the complex three-dimensional cluster of metal-oxide ions linked together by oxygen atoms. Here, a critical review on how POMs emerged from being molecular clusters for fundamental studies, to next-generation materials for energy applications is provided. We highlight how exploiting the versatility and activity of these molecules can lead to improved performance in energy devices such as supercapacitors and batteries, and in energy catalyst applications. The potential of POMs across numerous fields is systematically outlined by investigating structure-property-performance relationships and the determinant factors for energy systems. Finally, the challenges and opportunities for this class of materials with respect to addressing our pressing energy-related concerns are identified. This journal is © The Royal Society of Chemistry.
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| 10. |
- Sundriyal, S., et al.
(författare)
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Advances in bio-waste derived activated carbon for supercapacitors : Trends, challenges and prospective
- 2021
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Ingår i: Resources, Conservation and Recycling. - : Elsevier B.V.. - 0921-3449 .- 1879-0658. ; 169
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Tidskriftsartikel (refereegranskat)abstract
- The ever-increasing demand for green and clean energy urge the development of cheap and efficient electrode materials for supercapacitors (SCs). In this context, several naturally abundant bio-wastes have been explored to develop porous carbons for SCs due to their easy availability, high performances, and simple processing methods. Although various BDCs are utilized for SC, the relation between the bio-waste precursor and resultant carbon materials are not very well understood. Here, we highlight how the different bio-waste precursors affect the surface characteristics of the carbon nanostructures and outlined their subsequent effect on electrochemical performances. Moreover, the surface modification of carbon materials using pre-processing, carbonization and activation methods is provided. The supercapacitive properties of activated carbons (AC) with their unique surface features derived from the different feedstock are systematically summarized. Finally, the challenges and future directions for the development of AC from bio-waste are discussed. Overall, this review provides a guide to understand how best to refine and carbonize this biomass to achieve optimum supercapacitive performance. © 2021
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