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Open Access
Investigation of SiC based antireflection coatings for Si solar cells by numerical FTDT simulations
(The 8th International Conference on Nanomaterials and Advanced Energy Storage Systems; Nazarbayev University; National Laboratory Astana; Institute of Batteries, 2020-08) Sultanov, Assanali; Nussupov, Kair; Beisenkhanov, Nurzhan
Amorphous silicon-based thin layers (SiO2, SiN, a-SiC:H, and so on) for antireflection coatings, diffusion barriers, passivation layers have been broadly researched in the solar cell industry [1]. Such advantages of hydrogenated amorphous silicon carbide as a wide forbidden zone, excellent coefficient of thermal expansion, which corresponds to silicon wafers, relatively good thermal and mechanical stability [1,2], the possibility of being used as an antireflection and passivating layer simultaneously, make it an important material for use in solar cells. One of the key factors negatively affecting the efficiency of solar cells is the reflection of incident light. The use of antireflection coatings can significantly increase the amount of light involved in the generation of an electron-hole pairs, which in turn increases the efficiency of solar cells. Due to the effective refractive index n ranging from 2.560 to 2.832 and ease of synthesis [3], SiC has a high potential for use in antireflection coatings. In this paper, a series of simulations of SiC based antireflection coatings was carried out. The reflections of a single SiC layer, double-layer SiC-MgF2 coating and triple-layer SiC-ZnS-MgF2 coating in the range of wavelength from 300 to 800 nm was compared. The optimization of the results showed that the double-layer structure reaches a minimum reflection of 0.006% at the level of 737 nm. Moreover, in the interval from 475 to 800 nm, the reflection does not exceed 1%. Subsequently, the double-layer structure was compared with more classical combinations of ZnS-MgF2 and TiO2-SiO2. As the simulations show, SiC-MgF2 antireflective coating achieves better results indicating its high prospective for future application.
Open Access
Study of the lithium-ion battery at low temperatures
(The 8th International Conference on Nanomaterials and Advanced Energy Storage Systems; Nazarbayev University; National Laboratory Astana; Institute of Batteries, 2020-08) Mashekova, Aiym; Nurpeissova, Arailym; Bakenov, Zhumabay; Mukanova, Aliya
Nowadays, LIBs are one of the most demanded power sources due to their portability, high power and energy density. The performance of LIBs depends on ambient temperature, especially, at low temperatures. According to [1] kinetic reactions rate slows down at low working temperatures, due to physical and chemical electrolyte properties changes, such as viscosity and conductivity etc. The main function of the electrolyte is to transport lithium ions between the electrodes, which slows down due to a decrease in electrical conductivity at a low operating temperature of LIBs. Furthermore, the solid electrolyte interphase (SEI) morphology, components, and formation mechanism have significant impact on the performance of LIB. Therefore, the wide service temperature range and required properties of the electrolyte can be achieved by changing the combination and ratio of solvents, salts and additives. In present work, two types of lithium-ion cells (CR2032, MTI Corp.) were assembled in Ar-filled glovebox (LABmaster Pro, MBRAUN, <0.1 ppm H2O and O2). The first one was a reference and another one was with electrolyte additive. 1 M LiPF6 (LPF) in ethylene carbonate (EC)/dimethyl carbonate (DMC)/ethyl methyl carbonate (EMC) (1:1:1, by volume) was used as an electrolyte. The modified electrolyte was prepared by adding 3 wt. % acetonitrile (AN) to the above LPF-based electrolyte. Cathode slurry was prepared by mixing LiFePO4 (LFP), acetylene black (AB), and poly(vinyldifluoride) (PVDF) at a weight ratio of 80:15:5 in Nmethyl- pyrrolidone (NMP) solvent, lithium metal was used as an opposite and reference electrode. The electrochemical performance of the cells with and without AN additive was investigated at room and low (- 30 OC) temperature. All electrochemical cycling test results as well as synthesis routes and characterization details will be presented at the conference.
Open Access
Polymer Physics and Modeling of Polycarboxylate-based Superplasticizers
(The 8th International Conference on Nanomaterials and Advanced Energy Storage Systems; Nazarbayev University; National Laboratory Astana; Institute of Batteries, 2020-08) Ainakulova, Dana; Rakhmatulla, Samal; Karibayev, Mirat; Mentbayeva, Almagul; Wang, Yanwei
The tendency of developing urban areas brought a great demand for building materials in the last few decades. The innovation of new chemical admixtures has an increment in industry improving the rheology and early strength of cement-based material [1,2]. The use of modified polycarboxylate-based (PCE) superplasticizers in ready-mix or precast concrete cuts off required energy for construction decreasing the curing temperature and cost of building material. Moreover, the addition of superplasticizers results in a significant reduction to the annual worldwide CO2 emissions. Therefore, a continuous development of the PCE superplasticizers would be benign for us all if one considered the big picture of reducing the consumption of natural resources and energy. The research is a computational study, and our objective is to explore the polymer physics of PCE superplasticizers in aqueous solution and at liquid/solid interfaces using both the all-atom Molecular Dynamics (aaMD) and the Coarse-grained Molecular Dynamics Simulation (CGMD) simulation methods. More specifically, we are going to study (i) the interactions between PCE fragments and the various ions in a cement pore solution and how ions distribute around those PCE fragments; (ii) interactions of C-S-H surfaces with ions and calculations of the surface zeta potential [3]; and (iii) interactions between PCE fragments and C-S-H surfaces in the presence of ions using the aaMD simulation method. The aaMD method has a spatial resolution on the scale of a single atom, which is a great advantage when studying the physics of interfaces. However, it is rather computationally demanding to simulate polymers using the all-atom model, and that’s why we choose to work with PCE fragments instead of the entire macromolecule. The downside is that this choice may limit us from studying the polymer physics of PCE polymers [4]. In order to simulate the actual PCE polymers used in industry, we apply the CGMD simulation method by first developing coarse-grained models for PCE polymers in aqueous solution and then apply the same polymer model to study their conformational and adsorption properties at liquid/solid interfaces. We are particularly interested in exploring the physics of PCE polymers, which are comb-shaped copolymers with negatively charged backbones and neutral side chains, in the vicinity of a negatively charged surface with the presence of multi-valent cations [5].
Open Access
Composite PAAm-based hydrogel electrolyte for hybrid aqueous (Zn-Li-ion) battery
(The 8th International Conference on Nanomaterials and Advanced Energy Storage Systems; Nazarbayev University; National Laboratory Astana; Institute of Batteries, 2020-08) Zhanadilov, Orynbay; Mentbayeva, Almagul; Beisbayeva, Zhanna; Amze, Magzhan; Bakenov, Zhumabay
Hybrid aqueous rechargeable batteries are very attractive alternative to conventional rechargeable lithium ion batteries for stationary application because of production and usage safety, reduced production cost and environmental friendliness. Previously aqueous rechargeable batteries with Zn/LiCl-ZnCl2/LiFePO4 system with liquid electrolyte has been reported [1]. The system performed a high rate capability up to 60 C with the average operation voltage 1.2 V and cycling performance with a capacity retention of 80 % over 400 cycles at 6 C. However, there are several drawbacks including water decomposition and zinc dendrite formation hindering the commercialization [1]. The present study aimed to develop a PAAm-based hydrogel electrolyte with inclusion of montmorillonite and halloysite clay nanoparticles for hybrid aqueous rechargeable zinc/lithium ion batteries to overcome above mentioned problems. Polyacrylamide hydrogel was chosen because of its high ionic conductivity, high water content and simple fabrication method in which cross-linking degree, thickness, etc. were optimized. Inclusion of clay could improve mechanical stability of hydrogel electrolyte, prevent water decomposition and dendrite formation. All tests performed in Zn/LiFePO4 cell operating in an optimized LiCl/ZnCl2 aqueous electrolyte based hydrogel.
Open Access
“Quenched” Polyampholytes as Catalysts and Supercapacitors
(The 8th International Conference on Nanomaterials and Advanced Energy Storage Systems; Nazarbayev University; National Laboratory Astana; Institute of Batteries, 2020-08) Kudaibergenov, Sarkyt
The “quenched” or strongly charged polyampholytes represent amphoteric macromolecules consisting of static positive and negative charges [1,2]. The volume-phase, swelling-deswelling, self-healing, viscoelastic, and mechanical properties of „quenched” polyampholyte gels are discussed in aqueous-salt solutions together with their stimuli-responsive character [3]. Application aspects of „quenched” polyampholytes cover biotechnology, biomedicine, oil recovery, desalination, catalysis and supercapacitors [4,5]. Understanding of the fundamental relationships between the microstructure and property of crosslinked amphoteric macromolecules will open renewed interest to polyampholytes in whole and „quenched” polyampholytes in particular.
Open Access
Conformal coating of LTO/PAN for high performance Si nano-composite anodes
(The 8th International Conference on Nanomaterials and Advanced Energy Storage Systems; Nazarbayev University; National Laboratory Astana; Institute of Batteries, 2020-08) Mukhan, Orynbassar; Nurpeissova, Arailym; Bakenov, Zhumabay
Silicon is a potentially promising anode material for the next-generation energy storage devices owing to advantages as low cost, low toxicity and high specific capacity. However, there are several disadvantages of the silicon that shorten the life time of the battery such as instability of SEI layer, low electrical conductivity and volume change [1]. Huge volume expansion (>300%) during the lithiation/delithiation processes, which results in the pulverization of Si particles and fast capacity loss of the anode material, is considered as a major problem [2]. To be implemented commercially Si nanoparticles should exhibit high-power and low volume change. So far, there have been no credible Si-based materials reported satisfying all of these requirements [3]. Here, we report modified Si nanoparticles co-coated with Li4Ti5O12 and cyclized polyacrylonitrile targeted to enhance the conductivity and tolerance to volume change. The synergistic effect from both coating provide the Si electrode with good conductivity and better performance. Synthesized Si/LTO/cPAN composites were characterized by X-ray diffraction (XRD) and Scanning electron microscopy (SEM) to identify the structure and morphology of composites.
Open Access
Valorization of biomass waste into high efficient materials for CBRN protection
(The 8th International Conference on Nanomaterials and Advanced Energy Storage Systems; Nazarbayev University; National Laboratory Astana; Institute of Batteries, 2020-08) Mansurov, Zulkhair; Azat, Seitkhan; Kerimkulova, Almagul
Nowadays, the cleaning of aspiration and ventilation emissions from harmful substances is one of the main air protection measures for most of the industrial enterprises. The specific feature of most of the industrial emissions refers to the content of a large number of harmful gaseous components in addition to solid and liquid particles (dusts, gases, mists) [1]. The cleaning of the gas flows from such contaminants requires corresponding knowledge of the theory to develop gas purification methods. The adsorption method becomes more and more valuable among other known methods of industrial emissions cleaning as it allows almost complete removal of the contaminations of the gas flows. Many countries (Russia, USA, China, etc.) study intensively the problem of air cleaning. The scientists from the Institute on Combustion Problems perform studies [2-3] connected with the manufacture of modified carbon adsorbents for medical applications, waste waters cleaning from heavy metals ions, biomolecules division, etc. But the elaboration of carbon sorbents for toxic gases sorption has not been studied so far. This omission is treated in the present communication. This work is dedicated to the development of a method for the manufacture of modified carbon sorbents made for absorption of organic and inorganic vapors. The microstructure analysis of the samples reveals that the activation promotes the formation of a higher number of small pores and the development of a spongy texture of the sorbents leading to carbon content increase when compared to that of the initial sample. The final samples have apparent mesoporous confirmed by the form of the isotherms referring to the low-temperature adsorption of nitrogen and the results of pore size distribution using the DFT method.
Open Access
Simulation of Antireflection Coatings System Based on DLC/Porous Si and TiO2/SiO2 for Si Solar Cells
(The 8th International Conference on Nanomaterials and Advanced Energy Storage Systems; Nazarbayev University; National Laboratory Astana; Institute of Batteries, 2020-08) Nauryzbekova, Sholpan; Nussupov, Kair; Bakranova, Dina
The exploitation of diamond-like carbon (DLC) films in a wide range of practical applications attracts scientific interest [1]. More than 35% of solar radiation reflects from the surface of a silicon solar cell. This phenomenon negatively affects the quantity of generation of electron-hole pairs. Inhibiting of reflection can be achieved by applying anti-reflection coatings (ARC) on the silicon surface, with refractive indices n between n = 1 (Air) and n = 4.0 (Si). In the visible spectrum n = 1.5–3 for porous silicon, n = 2.4 for the DLC film, n = 1.5 for SiO2 and n = 2.1–2.5 for TiO2 [2]. By changing the thickness of the layers, the minimum of Inhibiting can be shifted to different parts of the spectrum. The deposition of two-layer films allows for expanding the useful range. A porous silicon layer has important advantages: the textured surface, the possibility of changing the bandgap, the ease of manufacture of the layer, and the variation of the refractive index by electrochemical anodization. Silicon DLC films are characterized by high mechanical, chemical, and radiation resistance.
Open Access
Magnetic and electronic properties of PtSe2 thin film
(The 8th International Conference on Nanomaterials and Advanced Energy Storage Systems; Nazarbayev University; National Laboratory Astana; Institute of Batteries, 2020-08) Toktarbaiuly, Olzat; Syrlybekov, Askar; Mauit, Ozhet
Two-dimensional (2D) materials with single or few atomic layers have attracted significant attention from the scientific community due to their potential transport physics and prospects for technological applications. A variety of 2D materials beyond graphene with different bandgaps have been synthesized in recent years. One of them is platinum diselenide (PtSe2) with the bandgap energy of 1.2 eV at one monolayer. However, the low throughput synthesis of high quality 2D thin films has thus far hindered the development of devices. The methods of molecular beam epitaxy (MBE) and chemical vapor deposition (CVD) have been used to achieve large-scale fabrication of PtSe2 films, which were fabricated from Pt thin films with different thickness through selenization process. We have grown Fe3O4 on MgO substrate by MBE system in order to fabricate even better epitaxial Pt thin films. After the fabrication of PtSe2 on Fe3O4/MgO, the electronic and magnetic properties of the interface between two epitaxial grown thin films of platinum diselenide and magnetite have been studied.
Open Access
Controlled Oxygen Redox for Excellent Power Capability in Layered Sodium‐Based Compounds
(The 8th International Conference on Nanomaterials and Advanced Energy Storage Systems; Nazarbayev University; National Laboratory Astana; Institute of Batteries, 2020-08) Kim, Hee Jae; Konarov, Aishuak; Myung, Seung-Taek
Recently, anionic oxygen redox (O2−/1−) become a main research subject for realizing high power capability [1]. Unfortunately, although the delivered capacity obtained from the transition-metal redox and oxygen redox is one of highest among sodium cathodes, the system suffers from not only serious capacity fading but also poor rate capability because of the sluggish kinetics of the oxygen redox [2]. To come up with this drawback, cobalt substitution in layered sodium-based compounds is conducted to achieve a high-rate of oxygen redox. The rationally designed Na0.6[Mg0.2Mn0.6Co0.2]O2 exhibits outstanding electrode performance, delivering a discharge capacity of 214 mAh g−1 (26 mA g−1) with capacity retention of 87% after 100 cycles. High rate performance is also achieved at 7C (1.82 A g−1) with a capacity of 107 mAh g−1. Surprisingly, the Na0.6[Mg0.2Mn0.6Co0.2]O2 compound is able to deliver capacity for 1000 cycles at 5C (at 1.3 A g−1), retaining 72% of its initial capacity of 108 mAh g−1. X-ray absorption spectroscopy analysis of the O K-edge indicates the oxygen-redox species (O2−/1−) is active during cycling. First-principles calculations show that the addition of Co reduces the bandgap energy from ≈2.65 to ≈0.61 eV and that overlapping of the Co 3d and O 2p orbitals facilitates facile electron transfer [3], enabling the long-term reversibility of the oxygen redox, even at high rates. To the best of the authors’ knowledge, this is the first report on high-rate oxygen redox in sodium-based cathode materials, and it is believed that the findings will open a new pathway for the use of oxygen-redox-based materials for sodium-ion batteries.
Open Access
Hydrothermal Low-cost Synthesis of ZnO-GO Nanocomposites
(The 8th International Conference on Nanomaterials and Advanced Energy Storage Systems; Nazarbayev University; National Laboratory Astana; Institute of Batteries, 2020-08) Kedruk, Y.Y.; Alpysbaiuly, N.; Gritsenko, L.V.; Abdullin, Kh.A.
One of the best known multifunctional semiconductor oxide materials is zinc oxide (ZnO). The wide band gap, high binding energy of exciton, radiation resistance, and high chemical stability make it a promising material for sensors [1], LEDs, solar cells, piezoelectric devices, transistors, etc. Recent studies have shown that composite materials based on ZnO and graphene oxide (GO) can have optical and electrical properties superior to those of ZnO [2]. This work is devoted to the development of the synthesis of photocatalytically active composites based on ZnO and graphene oxide by simple, low-cost effective methods. Graphene oxide was obtained by the Hammers method and then added to a solution for hydrothermal synthesis of zinc oxide. To form zinc oxide nanoparticles, a solution of sodium hydroxide NaOH at room temperature was added dropwise to a glass beaker with a solution of zinc acetate (CH3COO)2Zn×2H2O, after which the entire solution was thoroughly mixed on a magnetic stirrer for another 15 minutes. The resulting precipitate was washed with distilled water, separated by centrifugation, and then dried in an oven at 125ᵒC for 12 hours. The morphology, structural properties, and photocatalytic activity of the synthesized ZnO-GO samples were studied. Measurement of the photocatalytic activity of the obtained samples was carried out in relation to the degradation of Rhodamine-B (RhB) dye. It was noted that an increase in the GO concentration in the ZnO growth solution makes it possible to obtain more photocatalytically active ZnO – GO composites. Figure 1 shows the morphology of the ZnO-GO powder, containing 0.005 wt% GO, and the change in the optical density spectra of an aqueous solution of RhB in its presence.
Open Access
Enhancement of photovoltaic properties of polymer solar cells by modifying a structure of PEDOT: PSS layer
(The 8th International Conference on Nanomaterials and Advanced Energy Storage Systems; Nazarbayev University; National Laboratory Astana; Institute of Batteries, 2020-08) Ilyassov, B.R.; Aimukhanov, А.К.; Rozhkova, X.S.; Zeinidenov, А.К.; Nuraje, N.
Demand for developing robust renewable energy systems is increasing due to expiring fossil fuel deposits and ecological issues caused by using traditional energy sources. Among different renewable energy resources, solar energy is more attractive due to it can be transformed directly to heat, electricity or chemical energy. Photovoltaic devices are rapidly developing technology and have attracted attention of researchers and engineers from different fields. Polymer solar cells (PSCs) are very promising photovoltaic devices owing to facile fabrication method and cost-effectiveness of photoactive and semiconducting polymer materials [1]. PEDOT:PSS is semiconducting polymer materials with p-type conductivity which has become key components of PSCs [2]. The main role of PEDOT:PSS layer in PSCs is to extract photogenerated holes from photoactive layer and transport them to an external electrode [3]. The efficiency of hole extraction and transport depends on the quality of interface between PEDOT:PSS and photoactive layer and crystallinity of PEDOT:PSS. Here, we modified PEDOT:PSS layers obtaining by a spin-coating method from aqueous solution by adding 2-proponal. The improvement of structure and surface morphology was investigated by atomic force microscopy. Also, impedance spectroscopy technique was used to analyze charge transfer and transport. The modified PEDOT:PSS layers revealed better structure and surface morphology, and showed improved hole extraction and transport in comparison to an unmodified layer. PSCs with modified PEDOT:PSS layer have improved photovoltaic performance, which leads to enhancing the short circuit current density by 1.7 times, and power conversion efficiency and quantum efficiency of cells by 1.6 times.
Open Access
The Effect of Chemical Activating Agents on the Morphology and Structure of Bio-Derived Activated Carbon
(The 8th International Conference on Nanomaterials and Advanced Energy Storage Systems; Nazarbayev University; National Laboratory Astana; Institute of Batteries, 2020-08) Issatayev, Nurbolat; Nurpeissova, Arailym; Kalimuldina, Gulnur; Bakenov, Zhumabay
Recently, activated carbon (AC) has attracted more and more attention since it exhibits various properties, including operated pore size and morphology, strong mechanical and physico-chemical stability, good absorption capacity and crucially important, large surface area. This makes it an ideal material for use in energy storage, metal recovery, air purification, medical wastewater treatment, water purification, gas storage, and removal of caffeine. In this study, ACs were fabricated by single-stage carbonization and activation of a carbon precursor with four different chemical activating agents such as potassium hydroxide (KOH), zinc chloride (ZnCl2), phosphoric acid (H3PO4) and sulfuric acid (H2SO4), respectively. Agar-agar was used as a bio-derived carbon precursor due to its high carbon content and the lack of any traces of heavy metals. The effect of the activating agents and the weight ratio of activating reagents / precursor as well as the nature of the precursor have been examined and discussed. The morphological and textural properties of ACs were investigated using an electron scanning microscope (SEM), X-ray diffraction (XRD), Raman and FTIR techniques.
Open Access
Enhancing of charge transfer efficiency from a perovskite CH3NH3PbI3 film in a layer of titanium dioxide in the presence of Ag/SiO2 nanoparticles
(The 8th International Conference on Nanomaterials and Advanced Energy Storage Systems; Nazarbayev University; National Laboratory Astana; Institute of Batteries, 2020-08) Ibrayev, Niazbek; Afanasyev, Dmitriy; Toleutay, Dias
Using of localized plasmon resonance (LPR) in metal nanoparticles (NPs) is one of the promising directions for increasing of perovskite solar cells efficiency [1, 2]. Metal NPs coated dielectric shell can be used to exclude the contribution of the NPs to the total electrical conductivity of a perovskite films. The influence of LPR in the "core-shell" NPs on the process of charge transfer from a perovskite CH3NH3PbI3 layer to TiO2 layer is studied in the work. Samples with ITO−TiO2−CH3NH3PbI3 layers structure film were fabricated. Ti-Nanoxide BL/SC (Solaronix) paste were used for fabrication a compact TiO2 layers. CH3NH3PbI3 films synthesized by a one-step method [3]. 0.1 wt% Ag/SiO2 NPs with respect to the mass of the perovskite was added to a solution of a CH3NH3I•PbI2•DMSO adduct in dimethylformamide. The diameter of Ag NPs was 5 nm, and the radius of the dielectric shell (SiO2) was 2.5 nm. The addition of NPs to the adduct solution leads to the formation of the perovskite films with a lower optical density than the perovskite without NPs. A decrease in the intensity of the luminescence, and a blue shift in wavelengths of the luminescence intensity maximum is observed for the CH3NH3PbI3 films with NPs compared to this parameters for CH3NH3PbI3 films without NPs. The luminescence lifetime also decreases for the CH3NH3PbI3 with NPs. The intensity maximum of the luminescence kinetics for CH3NH3PbI3 with NPs has a time delay (0.05 - 0.1 ns) in comparison with the maximum luminescence intensity of perovskite without NPs. These results indicate an increase in the efficiency of charge transfer from perovskite to TiO2 in the presence of Ag/SiO2 NPs.
Open Access
Free energy of metal ion binding to some functional groups of concrete admixtures in water
(The 8th International Conference on Nanomaterials and Advanced Energy Storage Systems; Nazarbayev University; National Laboratory Astana; Institute of Batteries, 2020-08) Karibayev, Mirat; Zhao, Hongxia; Mentbayeva, Almagul; Wang, Yanwei
Concrete is the most used man-made materials on earth and has played a fundamental role in shaping our word, ranging from the cities we live in, roads and railways, to the infrastructure to support lower-carbon energy solutions [1]. Compared to other building materials, concrete is inherently a low carbon constructional material. However, as a result of the large volumes of concrete used, the production of Portland cement, the main binder of concrete, contributes 5–8% of annual anthropogenic global CO2 production [2,3] What can we do to reduce the carbon footprint and to further improve the environmental performance of concrete? Various solutions have been proposed and practiced, such as partial cement replacement by supplementary cementitious materials, development of low-carbon binders, reducing the amount of cementitious material altogether, and enhancement of concrete strength and durability; however, such solutions are often not possible without the development of efficient concrete admixtures, which have now become indispensable ingredients for the production of modern advanced concrete. There are two main types of concrete admixtures—chemical admixtures and mineral admixtures, both of which can be further grouped into various categories according to their function and chemical constituents. Our work focuses on the development of chemical admixtures, such as superplasticizers, slump-retaining admixtures, rheology modifying agents, and air entraining admixture. While those molecules are designed to sever different functions, most of them contain anionic functional groups and are supposed to act at interfaces [4]. However, the aqueous phase where chemical admixtures are dissolved in contains various metal cations, which may bind to the anionic functional groups of the chemical admixtures and play a profound role in their functions. We believe it is crucial to understand such binding interactions in order to understand the working mechanisms of chemical admixtures and to develop more efficient admixtures. Our current work has focused on calculations of the binding free energies of two different metal cations (Ca2+ and K+) with several different functional groups of chemical admixtures via two different methods—the quantum density functional theory (DFT) method and classical the force-field-based Metadynamics method. The binding free energies for potassium and calcium cations with different functional groups such as phosphonate, phosphate, carboxylate, sulfonate, sulfate, and alkoxide, as the complexes, have been explored in detail by the two methods.
Open Access
Metal oxides as additive to suppress dendrite formation on Zn anode of rechargeable aqueous battery
(The 8th International Conference on Nanomaterials and Advanced Energy Storage Systems; Nazarbayev University; National Laboratory Astana; Institute of Batteries, 2020-08) Rakhymbay, Lunara; Kurmanbayeva, Indira; Bakenov, Zhumabay
Recently rechargeable aqueous zinc-ion batteries have attend interest due to of their low cost and high safety advantages; but they still suffer from the problem of dendrite growth on Zn metal anodes than cause early battery destruction [1]. There are various methods for modification of surface of Zn metal anodes to suppress dendrite formation [2].Suppression of roughness or dendrite evolution by electroplating may also be achieved with ppm-levels of additives in the plating electrolyte. Several studies reporting the use of additives to control the Zn deposit quality and appearance are noted. Additives in these studies include polyvinyl alcohols, polyamines, carbonyl compounds and surfactants [3]. The role of metal oxides, namely germanium oxide, vanadium oxide, indium oxide and scandium oxide (100 ppm) have been investigated in the electroplating process on the surface of metallic zinc foil disks. The mix of 0.6M ZnCl2 and 0.1M NH4Cl in DI water worked as a plating solution. Synthesized Zn-metal oxide anodes characterized by X-ray diffraction and Scanning electron microscopy before and after cycling to study surface morphology, structural changes of anode and to evaluate dendrite growth.
Open Access
Advanced Functional Nanomaterials for Photocatalytic Water Splitting
(The 8th International Conference on Nanomaterials and Advanced Energy Storage Systems; Nazarbayev University; National Laboratory Astana; Institute of Batteries, 2020-08) Nuraje, Nurxat
Through mimicking Nature, unique assembled nanostructures can be designed and fabricated to improve certain properties of materials and device performance for targeted applications. In this presentation, we discuss the synthesis, and characterization of novel bio-inspired and biomimetic functional nanomaterials, and their properties. At the same time, we discuss how to apply them to investigate fundamental science in photocatalytic water splitting via creating their hierarchical nanostructured materials. In brief, this talk will focus on the following topics: (a) synthesis of bio-inspired functional nanomaterials; (b) fabrication of unique nanoarchitectures to better understand fundamental science; and (c) Applying these unique nanomaterials and nanostructures to resolve the scientific problems in Photocatalytic Water Splitting.
Open Access
Etching the surface of aluminum foil using high-frequency plasma to produce a nanoporous aluminum oxide membrane
(The 8th International Conference on Nanomaterials and Advanced Energy Storage Systems; Nazarbayev University; National Laboratory Astana; Institute of Batteries, 2020-08) Amirbekova, G.S.; Alpysbayeva, B.E.; Erlanuly, E.; Gabdullin, M. T.; Smirnov, V.Y.
In recent years, the trend of creating and improving sensitive sensors has taken an important place in the field of medicine, environmental monitoring and research of biomolecular interactions. In addition, these nanoporous aluminum oxide films are actively studied in the fields of nanoelectronics, microbiology, and nuclear physics [1]. In this research work, a porous aluminum oxide membrane with pre-treatment of the aluminum coating with plasma was developed for the first time. The process of processing the aluminum film with plasma in a high-frequency discharge, in a vacuum environment, and as a result, the surface oxide layer was destroyed and a surface roughness was formed. During the experiment, a vacuum medium with a Vup-5 device was adopted, a plasma with a pink tinge of 0.6-0.7 Pa was formed between the two electrodes, argon gas was obtained as the main gas, and room temperature was used as the temperature parameter. In order to determine the differences that occur on the surface of the film, the power size was obtained to such a different extent. And the processing time for all films is the same value t=15 minutes. The process of electrochemical anodizing into an aluminum film with this surface treated with plasma was also carried out. As the electrolyte, orthophosphor was obtained, the chemical reaction took place at room temperature 190C, voltage U=80 V, t=30 min. The process of electrochemical anodizing was a step-by-step process. In the experiment in vacuum environment, in a high-frequency discharge plasma treated surface layer of the aluminum film, based on the electrochemical anodization received nanoporous aluminium oxide. In the course of the study, it was noted that the change in parameters, in particular, differs from the surface roughness due to the different power values of 20 W 50 W and 70 W (Fig. 1).
Open Access
Solar cell research at an altitude of 3340 meters above sea level
(The 8th International Conference on Nanomaterials and Advanced Energy Storage Systems; Nazarbayev University; National Laboratory Astana; Institute of Batteries, 2020-08) Sadykov, T.Kh.; Zhukov, V.V.; Iskakov, B.A.; Nevmerzhitskiy, I.S.; Serikkanov, A.S.; Novolodskaya, О.А.; Tautayev, Y.М.
Providing electricity to consumers in the mountainous regions is one of the urgent problems of power engineers. Laying and maintenance of power lines is expensive because of the difficult terrain and climatic conditions Providing a heating system for heating boilers, requires the acquisition and delivery of large quantities of combustible material. The heating season in the highlands lasts up to nine months. Considering all the costs of electricity consumption and heating, it becomes necessary to conduct research and evaluate the economic efficiency of using solar power plants, focused on providing electricity to consumers in mountain regions. In order to create a scientific basis for solving innovative problems in solar energy at the Tien Shan high-mountain cosmic ray scientific station (TSHSS), located at an altitude of 3340 meters above sea level, initiative work is underway to create a solar power station (SPS), assess its effectiveness, safety , environmental friendliness and reliability in work. At the moment, a solar power station has been created at an altitude of 3340 meters above sea level. A comparative analysis of the results of generating electricity from the same type of solar power plants located at altitudes of 800 and 3340 meters above sea level was carried out. It is shown that the amount of electricity generated by a solar power plant at an altitude of 3340 is 20 percent more than at an altitude of 800 meters.
Open Access
Fabrication of back-contact solar cells by microsphere lithography
(The 8th International Conference on Nanomaterials and Advanced Energy Storage Systems; Nazarbayev University; National Laboratory Astana; Institute of Batteries, 2020-08) Umatova, Zarina; Jumabekov, Askhat
The back contact solar cells are a promising alternative to the traditional sandwich type devices. The most convenient and low cost method to fabricate back-contact solar cell devices is using microsphere lithography [1] as it can be performed without expensive photolithography tools and cleanroom. The self-assembly of polystyrene microbeads [2] was performed on top of APTES (3-Aminopropyl)triethoxysilane) functionalized surface of tin oxide layers on conductive glass substrates and deposited with magnetron sputtering. The deposition of microsphere beads on the substrates is achieved via electrostatic attraction forces between positively charged molecular monolayer-functionalized substrate and negatively charged micron-sized polystyrene microbeads with carboxyl surface groups. Resulting back-contact electrodes are used for fabrication of perovskite solar cell devices. Copper was chosen as a cathode layer in order to adapt existing processes on plastic substrates due to lower oxidation temperatures [3] compared to nickel [4].