| 1. |
- Alluri, Nagamalleswara Rao, et al.
(författare)
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Crystallinity modulation originates ferroelectricity like nature in piezoelectric selenium
- 2022
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Ingår i: Nano Energy. - : Elsevier. - 2211-2855 .- 2211-3282. ; 95
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Tidskriftsartikel (refereegranskat)abstract
- Modern room temperature ferroelectrics/piezoelectrics significantly impact advanced nanoelectronics than conventional chemical compounds. Changes in crystallinity modulation, long-range order of atoms in metalloids permits the design of novel materials. The ferroelectric like nature of a single element (selenium, Se) is demonstrated via in-plane (E perpendicular to(ar) to the Se helical chains in micro-rod (MR)) and out-of-plane (E parallel to(el) to the Se helical chains in MR) polarization. Atomic electron microscopy shows large stacks of covalently bound Se atoms in a c-axis orientation for tip bias voltage-dependent switchable domains with a 180 degrees phase and butterfly displacement curves. The single crystalline Se MR has a high in-plane piezoelectric coefficient of 30 pm/V relative to polycrystalline samples due to larger grains, crystal imperfections in MR, and tuned helical chains. The energy conversion of a single Se-MR demonstrated via d(13), d(12) (or d(15)) piezoelectric modes.
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| 2. |
- Araujo, Rafael B., et al.
(författare)
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High-entropy alloy catalysts : Fundamental aspects, promises towards electrochemical NH3 production, and lessons to learn from deep neural networks
- 2023
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Ingår i: Nano Energy. - : Elsevier. - 2211-2855 .- 2211-3282. ; 105
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Tidskriftsartikel (refereegranskat)abstract
- A computational approach to judiciously predict high-entropy alloys (HEAs) as an efficient and sustainable material class for the electrochemical reduction of nitrogen is here presented. The approach employs density functional theory (DFT), adsorption energies of N atoms and N2 molecules as descriptors of the catalytic activity and deep neural networks. A probabilistic approach to quantifying the activity of HEA catalysts for nitrogen reduction reaction (NRR) is described, where catalyst elements and concentration are optimized to increase the probability of specific atomic arrangements on the surfaces. The approach provides key features for the effective filtering of HEA candidates without the need for time-consuming calculations. The relationships between activity and selectivity, which correlate with the averaged valence electron concentration and averaged electronegativity of the reference HEA catalyst, are analyzed in terms of sufficient interaction for sustained reactions and, at the same time, for the release of the active site. As a result, a complete list of 3000 HEAs consisting of quinary components of the elements Mo, Cr, Mn, Fe, Co, Ni, Cu, and Zn are reported together with their metrics to rank them from the most likely to the least likely active catalysts for NRR in gas diffusion electrodes, or for the case where non-aqueous electrolytes are utilized to suppress the competing hydrogen evolution reaction. Moreover, the energetic landscape of the electrochemical NRR transformations are computed and compared to the case of Fe. The study also analyses and discusses how the results would translate to liquid-solid reactions in aqueous electrochemical cells, further affected by changes in properties upon hydroxylation, oxygen, hydrogen, and water coverages.
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| 3. |
- Aslam, Muhammad Kashif, et al.
(författare)
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How to avoid dendrite formation in metal batteries : Innovative strategies for dendrite suppression
- 2021
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Ingår i: Nano Energy. - : Elsevier. - 2211-2855 .- 2211-3282. ; 86
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Forskningsöversikt (refereegranskat)abstract
- With increasing the diversity of electronic/electric appliances and large-scale energy storage systems, highenergy-density based device technology has been in great demand. Meanwhile, for developing of high-voltage and high-capacity cathode, the use of metals including lithium (Li), sodium (Na), potassium (K), or zinc (Zn) is quite impressive to replace the traditional anodes with low capacity upper limit such as graphite, silicon carbon, and hard carbon which is considered as "holy grail" strategy to explore high-energy density systems. However, these so-called metal batteries (MBs) also face many thorny issues including high anode reactivity, dendritic growth, and high safety risks. Among all these muddle, the dendrite growth is quite sever issue and has attracted much attention of many recognized materials scientist and battery researchers. The formation of dendrite increase the surface area of metal anodes, induce the rupture and reconstruction of solid electrolyte interphase (SEI) film, which is likely to accelerate the excessive consumption of electrolyte and the formation of dead metals. Consequently, battery lose its capability and short circuit produced which causes serious safety issues. Therefore, it is badly needed to inhibit or even eliminate the formation of dendrites during the repeated charge and discharge process to find advanced and fast battery technology. In this review, we summarize the basic mechanistic theoretical models about dendrites formation and their effects on the battery performance. Moreover, we recapitulate the reported literature about dendrites concept and their solution from battery invention to its modernism for smart electric appliances and zero emission electric vehicles. Besides, perspective of interface energy/volume stress, several innovative strategies for restraining, regulating and eliminating dendrites are also part of this review. Finally, perspectives conclusions for the development of MBs about dendrite level are given for the progress of future battery science.
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| 4. |
- Banerjee, Amitava, et al.
(författare)
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Identifying the tuning key of disproportionation redox reaction in terephthalate : A Li-based anode for sustainable organic batteries
- 2018
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Ingår i: Nano Energy. - : Elsevier BV. - 2211-2855 .- 2211-3282. ; 47, s. 301-308
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Tidskriftsartikel (refereegranskat)abstract
- The ever-increasing consumption of energy storage devices has pushed the scientific community to realize strategies toward organic electrodes with superior properties. This is owed to advantages such as economic viability and eco-friendliness. In this context, the family of conjugated dicarboxylates has emerged as an interesting candidate for the application as negative electrodes in advanced Li-ion batteries due to the revealed thermal stability, rate capability, high capacity and high cyclability. This work aims to rationalize the effects of small molecular modifications on the electrochemical properties of the terephthalate anode by means of first principles calculations. The crystal structure prediction of the investigated host compounds dilithium terephthalate (Li2TP) and diethyl terephthalate (Et2Li0TP) together with their crystal modification upon battery cycling enable us to calculate the potential profile of these materials. Distinct underlying mechanisms of the redox reactions were obtained where Li2TP comes with a disproportionation reaction while Et2Li0TP displays sequential redox reactions. This effect proved to be strongly correlated to the Li coordination number evolution upon the Li insertion into the host structures. Finally, the calculations of sublimation enthalpy inferred that polymerization techniques could easily be employed in Et2Li0TP as compared to Li2TP. Similar results are observed with methyl, propyl, and vinyl capped groups. That could be a strategy to enhance the properties of this compound placing it into the gallery of the new anode materials for state of art Li-batteries.
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| 5. |
- Banerjee, Debashree, et al.
(författare)
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Elevated thermoelectric figure of merit of n-type amorphous silicon by efficient electrical doping process
- 2018
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Ingår i: Nano Energy. - : Elsevier BV. - 2211-2855 .- 2211-3282. ; 44, s. 89-94
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Tidskriftsartikel (refereegranskat)abstract
- The currently dominant thermoelectric (TE) materials used in low to medium temperature range contain Tellurium that is rare and mild-toxic. Silicon is earth abundant and environment friendly, but it is characterized by a poor TE efficiency with a low figure of merit, ZT. In this work, we report that ZT of amorphous silicon (a-Si) thin films can be enhanced by 7 orders of magnitude, reaching ∼0.64 ± 0.13 at room temperature, by means of arsenic ion implantation followed by low-temperature dopant activation. The dopant introduction employed represents a highly controllable doping technique used in standard silicon technology. It is found that the significant enhancement of ZT achieved is primarily due to a significant improvement of electrical conductivity by doping without crystallization so as to maintain the thermal conductivity and Seebeck coefficient at the level determined by the amorphous state of the silicon films. Our results open up a new route towards enabling a-Si as a prominent TE material for cost-efficient and environment-friendly TE applications at room temperature.
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| 6. |
- Bayrak Pehlivan, Ilknur, et al.
(författare)
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Electrochromic solar water splitting using a cathodic WO3 electrocatalyst
- 2021
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Ingår i: Nano Energy. - : Elsevier. - 2211-2855 .- 2211-3282. ; 81
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Tidskriftsartikel (refereegranskat)abstract
- Solar-driven water splitting is an emerging technology with high potential to generate fuel cleanly and sustainably. In this work, we show that WO3 can be used as a cathodic electrocatalyst in combination with (Ag,Cu) InGaSe2 solar cell modules to produce hydrogen and provide electrochromic functionality to water splitting devices. This electrochromic effect can be used to monitor the charge state or performance of the catalyst for process control or for controlling the temperature and absorbed heat due to tunable optical modulation of the electrocatalyst. WO3 films coated on Ni foam, using a wide range of different sputtering conditions, were investigated as cathodic electrocatalysts for the water splitting reaction. The solar-to-hydrogen (STH) efficiency of solar-driven water electrolysis was extracted using (Ag,Cu)InGaSe2 solar cell modules with a cell band gap varied in between 1.15 and 1.25 eV with WO3 on Ni foam-based electrolyzers and yielded up to 13% STH efficiency. Electrochromic properties during water electrolysis were characterized for the WO3 films on transparent substrate (indium tin oxide). Transmittance varied between 10% and 78% and the coloration efficiency at a wavelength of 528 nm and the overpotential of 400 mV was 40 cm(2) C-1. Hydrogen ion consumption in ion intercalation for electrochromic and hydrogen gas production for water electrolysis processes was discussed.
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| 7. |
- Benetti, Daniele, et al.
(författare)
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Hole-extraction and photostability enhancement in highly efficient inverted perovskite solar cells through carbon dot-based hybrid material
- 2019
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Ingår i: Nano Energy. - : Elsevier. - 2211-2855 .- 2211-3282. ; 62, s. 781-790
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Tidskriftsartikel (refereegranskat)abstract
- We report the effect of the integration of carbon dots (Cdots) in high-performance inverted planar-heterojunction (PHJ) perovskite solar cells (PSCs). We used Cdots to modify the hole-transport layer in planar PSC devices. By introducing Cdots on graphene oxide (GO) as hole-transporting layer, the efficiency of the PSC improved significantly from 14.7% in the case of bare GO to 16.2% of the best device with optimized Cdots content. When applying Cdots with an engineered absorption in the UV range as downshifting layer, the device performance was further improved, attaining a maximum PCE of 16.8% (+14%); the stability of the device was also enhanced of more than 20%. Kelvin probe force microscopy (KPFM) and cyclic voltammetry (CV) were employed to analyze the electronic band alignment at the interface between GO/Cdots and the perovskite film. Holes were extracted and transferred to the conductive substrate more efficiently in the presence of Cdots, thus delaying charge recombination. Photoluminescence (PL), transient PL decays and transient photovoltage (TPV) decays investigated the charge-transfer kinetics and proved the retardation of charge recombination. This work reveals an effective enhancement of the performance of planar PSCs by using Cdots/GO as hole transport material.
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| 8. |
- Bi, Zhaozhao, et al.
(författare)
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Individual nanostructure optimization in donor and acceptor phases to achieve efficient quaternary organic solar cells
- 2019
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Ingår i: Nano Energy. - : ELSEVIER. - 2211-2855 .- 2211-3282. ; 66
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Tidskriftsartikel (refereegranskat)abstract
- Fullerene derivative (PC71BM) and high crystallinity molecule (DR3TBDTT) are employed into PTB7-Th:FOIC based organic solar cells (OSCs) to cooperate an individual nanostructure optimized quaternary blend. PC71BM functions as molecular adjuster and phase modifier promoting FOIC forming "head-to-head" molecular packing and neutralizing the excessive FOIC crystallites. A multi-scale modified morphology is present thanks to the mixture of FOIC and PC71BM while DR3TBDTT disperses into PTB7-Th matrix to reinforce donors crystal-linity and enhance domain purity. Morphology characterization highlights the importance of individually optimizated nanostructures for donor and acceptor, which contributes to efficient hole and electron transport toward improved carrier mobilities and suppressed non-geminated recombination. Therefore, a power conversion efficiency of 13.51% is realized for a quaternary device which is 16% higher than the binary device (PTB7-Th:FOIC). This work demonstrates that utilizing quaternary strategy for simultaneous optimization of donor and acceptor phases is a feasible way to realize high efficient OSCs.
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| 9. |
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| 10. |
- Chen, Libo, et al.
(författare)
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Artificial tactile peripheral nervous system supported by self-power transducers
- 2021
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Ingår i: Nano Energy. - : Elsevier. - 2211-2855 .- 2211-3282. ; 82
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Tidskriftsartikel (refereegranskat)abstract
- The tactile peripheral nervous system innervating human hands, which is essential for sensitive haptic exploration and dexterous object manipulation, features overlapped receptive fields in the skin, arborization of peripheral neurons and many-to-many synaptic connections. Inspired by the structural features of the natural system, we report a supersensitive artificial slowly adapting tactile afferent nervous system based on the triboelectric nanogenerator technology. Using tribotronic transistors in the design of mechanoreceptors, the artificial afferent nervous system exhibits the typical adapting behaviours of the biological counterpart in response to mechanical stimulations. The artificial afferent nervous system is self-powered in the transduction and event-driven in the operation. Moreover, it has inherent proficiency of neuromorphic signal processing, delivering a minimum resolvable dimension two times smaller than the inter-receptor distance which is the lower limit of the dimension that existing electronic skins can resolve. These results open up a route to scalable neuromorphic skins aiming at the level of human?s exceptional perception for neurorobotic and neuroprosthetic applications.
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