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9 pages, 5752 KiB

Open AccessCommunication

Flexibility-Engineered Nb₂O₅ Carbon Nanofiber Film Anodes: Concentration-Dependent Optimization for Mechanically Robust and Stable Sodium Storage

by Xuhui Zhu, Duiming Lin, Siying Liu, Jufang Li, Yi Tang, Yancheng Pan, Qinglin Deng and Lingmin Yao

Coatings 2025, 15(4), 374; https://doi.org/10.3390/coatings15040374 - 22 Mar 2025

Viewed by 213

Abstract

This study systematically investigates the correlation between the concentration of niobium oxide (Nb₂O₅) in carbon nanofibers (CNFs) and the microstructural characteristics and electrochemical performance of the composites. Through rational optimization of Nb₂O₅-to-CNFs mass ratios, we [...] Read more.

This study systematically investigates the correlation between the concentration of niobium oxide (Nb₂O₅) in carbon nanofibers (CNFs) and the microstructural characteristics and electrochemical performance of the composites. Through rational optimization of Nb₂O₅-to-CNFs mass ratios, we demonstrate that 50% Nb₂O₅ CNFs composite achieves an optimal balance between enhanced rate capability and structural stability. The composites transition from brittle to flexible with increasing Nb₂O₅ content, achieving unprecedented bending durability at 50% loading. This mechanical–electrochemical synergy positions Nb₂O₅ CNFs as viable candidates for flexible energy storage devices. Comprehensive characterization reveals that appropriate Nb₂O₅ incorporation significantly improves specific capacity (181 mA h g⁻¹ at 0.1 A g⁻¹) and rate performance compared to pristine CNFs. However, excessive Nb₂O₅ doping (>50%) induces detrimental hydrolysis reactions during synthesis, compromising both material processability and electrochemical reversibility. This work contributes to the development of flexible self-supporting frameworks that are superior to hard carbon for constructing high-performance flexible sodium-ion batteries. Full article

(This article belongs to the Special Issue New Functional Coatings and Thin Films for Sensor and Green Energy Technologies)

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9 pages, 3927 KiB

Open AccessArticle

Electrodeposition of Metallic Tungsten Coating on 9Cr-ODS Steel Substrate from Binary Oxide Molten Salt

by Xiaoxu Dong, Yusha Li, Yajie You, Zeyu Gao and Yingchun Zhang

Coatings 2025, 15(3), 257; https://doi.org/10.3390/coatings15030257 - 21 Feb 2025

Viewed by 421

Abstract

Characteristics of electrodeposited tungsten coatings prepared at 1193 K and varying current density were investigated. The crystal structure and microstructure of tungsten coatings were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and photoelectron spectroscopy (XPS). The results indicated that pulsed current [...] Read more.

Characteristics of electrodeposited tungsten coatings prepared at 1193 K and varying current density were investigated. The crystal structure and microstructure of tungsten coatings were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and photoelectron spectroscopy (XPS). The results indicated that pulsed current density significantly influence the tungsten nucleation and electro-crystallization phenomena. The average grain size of the coating becomes larger with increasing current density, which demonstrates that appropriate high cathodic current density can accelerate the growth of grains on the surface of the substrate. The micro-hardness of tungsten coatings increases with increasing thickness and then slightly decreases; the maximum micro-hardness is 589.55 HV, with the oxygen content remaining below 0.03 wt%. Full article

(This article belongs to the Special Issue New Functional Coatings and Thin Films for Sensor and Green Energy Technologies)

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16 pages, 7843 KiB

Open AccessArticle

Structural Aspects and Adhesion of Polyurethane Composite Coatings for Surface Acoustic Wave Sensors

by Mauro dos Santos de Carvalho, Michael Rapp, Achim Voigt, Marian Dirschka and Udo Geckle

Coatings 2025, 15(2), 139; https://doi.org/10.3390/coatings15020139 - 24 Jan 2025

Viewed by 690

Abstract

Surface acoustic wave-based (SAW) sensors are of great interest due to their high sensibility and fast and stable responses. They can be obtained at an overall low cost and with an intuitive and easy-to-use method. The chemical sensitization of a piezoelectric transducer plays [...] Read more.

Surface acoustic wave-based (SAW) sensors are of great interest due to their high sensibility and fast and stable responses. They can be obtained at an overall low cost and with an intuitive and easy-to-use method. The chemical sensitization of a piezoelectric transducer plays a key role in defining the properties of SAW sensors. In this study, we investigate the structural and adhesion properties of a new class of coating material based on polyurethane polymeric composites. We used dark-field microscopy (DFM) and scanning electron microscopy (SEM) to observe the microstructure of polyurethane composite coatings on piezoelectric sensor elements and to analyze the effects of the chemical resistance and adhesion test (CAT) on the coating layers obtained with the polyurethane polymeric composites. The results of the microscopy showed that all polyurethane composite coatings exhibited excellent uniformity and stability after chemical adherence testing (CAT). All of the observations were correlated with the results of the ultrasonic analysis, which demonstrated the role of polyurethane as a binder to form the stable structure of the composites and, at the same time, as an adhesion promoter, increasing the chemical resistance and the adherence of the coating layer to the complex surface of the piezoelectric sensor element. Full article

(This article belongs to the Special Issue New Functional Coatings and Thin Films for Sensor and Green Energy Technologies)

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9 pages, 4300 KiB

Open AccessArticle

Preparation and Properties of Thick Tungsten Coating Electrodeposited from Na₂WO₄-WO₃-KCl-NaF Molten Salt System

by Yusha Li, Xiaoxu Dong, Qing Liu, Yajie You, Zeyu Gao and Yingchun Zhang

Coatings 2024, 14(11), 1471; https://doi.org/10.3390/coatings14111471 - 20 Nov 2024

Viewed by 809

Abstract

The pulsed current electrodeposition method was employed for the first time to achieve tungsten coating with a thickness of 433.72 μm on a CuCrZr alloy from Na₂WO₄-WO₃-KCl-NaF molten salt. The microstructure of the coating was observed and [...] Read more.

The pulsed current electrodeposition method was employed for the first time to achieve tungsten coating with a thickness of 433.72 μm on a CuCrZr alloy from Na₂WO₄-WO₃-KCl-NaF molten salt. The microstructure of the coating was observed and the coating density, porosity, hardness, bonding strength, residual stress and oxygen content were tested. The results revealed that the tungsten coating exhibited desirable characteristics such as high density, absence of impurities, excellent adhesion to the matrix (53.16 MPa), residual compressive stress as surface stress, and good stability and durability. Moreover, this thick tungsten coating possesses high density and hardness, low oxygen content and porosity. This offers a novel solution to solve the challenging issue of the connection between tungsten material and heat sink material. Full article

(This article belongs to the Special Issue New Functional Coatings and Thin Films for Sensor and Green Energy Technologies)

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15 pages, 4353 KiB

Open AccessArticle

Impact of Substrate upon Morphology, Luminescence, and Wettability of ZnMgO Layers Deposited by Spray Pyrolysis

by Eduard V. Monaico, Vadim Morari, Stepan Buiucli, Victor V. Zalamai, Veaceslav V. Ursaki and Ion M. Tiginyanu

Coatings 2024, 14(11), 1395; https://doi.org/10.3390/coatings14111395 - 2 Nov 2024

Cited by 1 | Viewed by 1414

Abstract

In this work, we report on a comparative study of the topology, luminescence, and wettability properties of ZnMgO films prepared by a cost-effective spray pyrolysis technology on GaAs substrates with (100), (001), and (111) crystallographic orientations, as well as on Si(100) substrates. Deposition [...] Read more.

In this work, we report on a comparative study of the topology, luminescence, and wettability properties of ZnMgO films prepared by a cost-effective spray pyrolysis technology on GaAs substrates with (100), (001), and (111) crystallographic orientations, as well as on Si(100) substrates. Deposition on nanostructured GaAs substrates was also considered. It was found that film growth is not epitaxial or conformal, but rather, it is granular, depending on the nucleating sites for the crystallite growth. The distribution of nucleation sites ensured the preparation of nanostructured films with good uniformity of their topology. The observed difference in columnar growth on Si substrates and pyramidal growth on GaAs ones was explained in terms of the impact of chemical bonding in substrates. The films grown on GaAs substrates with a (001) orientation were found to be made of larger crystallites compared to those deposited on substrates with a (111) orientation. These effects resulted in a difference in roughness of a factor of 1.5, which correlates with the wetting properties of films, with the most hydrophobic surface being found on films deposited on GaAs substrates with a (111) orientation. The prospects for photocatalytic and gas sensor applications of films produced on flat substrates, as well as for plasmonic and other applications of films deposited on nanostructured substrates, are discussed, taking into account the results of the analysis of their photoluminescence properties. Full article

(This article belongs to the Special Issue New Functional Coatings and Thin Films for Sensor and Green Energy Technologies)

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13 pages, 1966 KiB

Open AccessArticle

Optimization of LPCVD Deposition Conditions of Silicon-Rich Silicon Nitride to Obtain Suitable Optical Properties for Photoluminescent Coating

by Francisco Uribe González, Karim Monfil Leyva, Mario Moreno Moreno, Alfredo Morales Sánchez, Ana L. Muñoz Zurita, José A. Luna López, Jesús Carrillo López, José A. D. Hernández de la Luz and Alma S. L. Salazar Valdez

Coatings 2024, 14(11), 1383; https://doi.org/10.3390/coatings14111383 - 31 Oct 2024

Viewed by 1366

Abstract

Silicon nitride is a commonly used material for ceramic applications and in the fabrication processes of integrated circuits (ICs). It has also increased in interest from the scientific community for use as a functional coating due to its physical, mechanical, electrical, and optoelectronic [...] Read more.

Silicon nitride is a commonly used material for ceramic applications and in the fabrication processes of integrated circuits (ICs). It has also increased in interest from the scientific community for use as a functional coating due to its physical, mechanical, electrical, and optoelectronic properties. In particular, silicon-rich silicon nitride (SRSN) has been considered in the photovoltaic industry as a down-conversion film for solar cells. In this work, SRSN films have been obtained by the Low-Pressure Chemical Vapor Deposition (LPCVD) technique at low to moderate deposition temperatures with a variation in the precursor gas pressure ratio. The SRSN films showed a wide photoluminescence (PL) in the visible region (without a high-deposition temperature or annealing process) and suitable optical properties (refractive index and absorption in the UV) to be used as photoluminescent coating on silicon solar cells. The absence of high-deposition temperatures could preserve the original structure of silicon solar cells, once the SRSN layer was applied. In addition, control of the reactive gas pressure ratio and deposition temperature showed an influence on the refractive index, the surface roughness, and the PL emission. Full article

(This article belongs to the Special Issue New Functional Coatings and Thin Films for Sensor and Green Energy Technologies)

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19 pages, 3948 KiB

Open AccessArticle

A Spray-Deposited Modified Silica Film on Selective Coatings for Low-Cost Solar Collectors

by Francisco Ivan Lizama-Tzec, Marco de Jesús Cetina-Dorantes, Dallely Melissa Herrera-Zamora, Juan José Alvarado-Gil, Geonel Rodríguez-Gattorno, Manuel Alejandro Estrella-Gutiérrez, Octavio García-Valladares, Caridad Vales-Pinzón and Gerko Oskam

Coatings 2024, 14(11), 1368; https://doi.org/10.3390/coatings14111368 - 27 Oct 2024

Cited by 1 | Viewed by 1159

Abstract

Solar collectors represent an attractive green technology for water heating, where sunlight is efficiently absorbed by a selective coating and the generated heat is transferred to water. In this work, the improvement and scale-up of an electrodeposited black nickel selective coating with a [...] Read more.

Solar collectors represent an attractive green technology for water heating, where sunlight is efficiently absorbed by a selective coating and the generated heat is transferred to water. In this work, the improvement and scale-up of an electrodeposited black nickel selective coating with a modified silica (MS) film deposited by spray pyrolysis are reported. The MS material was prepared by the sol–gel method using tetraethyl orthosilicate with the addition of n-propyl triethoxysilane to obtain a porous film with an adequate refractive index and enhanced flexibility. The reflectance of electrodeposited selective coatings was characterized with and without the MS film and compared to a commercially available coating of black paint. The MS film increased the solar absorptance from 89% to 93% while maintaining a much lower thermal emittance than the painted coating. The reflectance of the MS film remained unchanged after prolonged thermal treatment at 200 °C (200 h). The fabrication process was scaled up to 193 cm × 12 cm copper fins, which were incorporated in commercial-size flat-plate solar collectors. Three complete collectors of an area of 1.7 m² were fabricated and their performance was evaluated under outdoor conditions. The results show that the electrodeposited selective coating with the MS film outperformed both the commercial black paint system and the system without the modified silica film. Full article

(This article belongs to the Special Issue New Functional Coatings and Thin Films for Sensor and Green Energy Technologies)

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15 pages, 2381 KiB

Open AccessArticle

Inorganic Salts as Chemical Foam Suppressors

by Niravkumar Raykundaliya, Stoyan I. Karakashev, Vyomesh M. Parsana, Nikolay A. Grozev, Kristina Mircheva and Dilyana Ivanova-Stancheva

Coatings 2024, 14(11), 1358; https://doi.org/10.3390/coatings14111358 - 25 Oct 2024

Viewed by 935

Abstract

Can the foamability of surfactant aqueous solutions be controlled chemically? Well-known antifoams can prevent foaming by inducing the coalescence of the bubbles, but can the surfactants be deactivated chemically? If yes, how does this affect the surface tension of their aqueous solutions and [...] Read more.

Can the foamability of surfactant aqueous solutions be controlled chemically? Well-known antifoams can prevent foaming by inducing the coalescence of the bubbles, but can the surfactants be deactivated chemically? If yes, how does this affect the surface tension of their aqueous solutions and their foaming capacity? To shed a light on these fundamental questions, we chose a well-known surfactant containing in its molecule a sulfate group (Sodium dodecyl sulfate, SDS) and mixed it with BaCl₂, (the solubility of BaSO₄ is 0.245 mg/100 mL water, T = 20 °C), Pb(NO₃)₂ (the solubility of PbSO₄ is 40.4 mg/100 mL water, T = 25 °C) and FeCl₃ (the solubility of Fe₂(SO₄)₃ is 25.6 g/100 mL water, T = 20 °C) at different molar ratios (MX_n/SDS): 1/2, 1/1, 2/1, 4/1. The results were surprising: in the case of BaCl₂, despite being in stoichiometric molar ratio with SDS (BaCl₂ + 2SDS -> Ba(DS)₂ + 2 NaCl), or in excess of BaCl₂, which should convert the whole amount of SDS into a sediment, the surface tension value remained significantly lower than that of the single surfactant. At the same time, foamability was either low or absent. It therefore appears that all of the surfactants should be converted into a sediment with very small solubility, but the low surface tension indicates the opposite. The lack of foamability indicated the opposite of that opposite. With Pb(NO₃)₂ and FeCl₃, the results are even stranger. The surface tension values are substantially smaller than those of the single surfactants, and at the same time, low foamability or lack of foamability was observed. It appears that the surfactant exists and at the same time does not exist in the aqueous solution. Where is the truth? Future studies will shed a light. Full article

(This article belongs to the Special Issue New Functional Coatings and Thin Films for Sensor and Green Energy Technologies)

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9 pages, 2460 KiB

Open AccessArticle

Effect of Low-Energy Implantation of In⁺ Ions on the Composition and Electronic Structure of Single-Crystal GaP(111)

by Sardor Donaev, Ganjimurod Shirinov, Baltokhodja Umirzakov, Burkhan Donayev and Shenghao Wang

Coatings 2024, 14(10), 1231; https://doi.org/10.3390/coatings14101231 - 24 Sep 2024

Viewed by 852

Abstract

Using a complex of secondary and photoelectron spectroscopy methods, the effects of the implantation of In⁺ ions with an energy of E₀ = 1 keV at different doses and subsequent annealing on the composition, electronic, and crystal structure of the GaP(111) [...] Read more.

Using a complex of secondary and photoelectron spectroscopy methods, the effects of the implantation of In⁺ ions with an energy of E₀ = 1 keV at different doses and subsequent annealing on the composition, electronic, and crystal structure of the GaP(111) surface were studied. It is shown that in the dose range D ≈ 5 × 10¹⁴–5 × 10¹⁵ cm⁻² after annealing, nanocrystalline phases Ga_0.6In_0.4P are formed with surface dimensions d ≈ 10–30 nm, and at D ≥ 6 × 10¹⁶ cm⁻² nanofilm–Ga_0.6In_0.4P with a thickness of 30–35 nm. It has been found that the band gap of nanophases (E_g ≈ 2–2.3 eV) is much larger than Eg of the film (~1.85 eV). For the first time, information was obtained on the density of state of electrons in the valence band of nanophases and nanofilm GaInP. Full article

(This article belongs to the Special Issue New Functional Coatings and Thin Films for Sensor and Green Energy Technologies)

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15 pages, 5343 KiB

Open AccessArticle

Effect of the Atmosphere on the Properties of Aluminum Anodizing

by Gabriela Baltierra-Costeira, Jesús Emilio Camporredondo-Saucedo, Marco Arturo García-Rentería, Lázaro Abdiel Falcón-Franco, Laura Guadalupe Castruita-Ávila and Adrián Moisés García-Lara

Coatings 2024, 14(9), 1166; https://doi.org/10.3390/coatings14091166 - 10 Sep 2024

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Abstract

This study aims to quantify the effect of process parameters on the anodizing of Al6061 aluminum. To achieve this, studies on layer thickness, the porosity of the anodized surface, electrochemical techniques, X-ray diffraction, grain size estimation, and statistical analysis were conducted for three [...] Read more.

This study aims to quantify the effect of process parameters on the anodizing of Al6061 aluminum. To achieve this, studies on layer thickness, the porosity of the anodized surface, electrochemical techniques, X-ray diffraction, grain size estimation, and statistical analysis were conducted for three different atmospheres (without air, air, and oxygen). Parameter levels were established as follows: temperature (30 °C, 45 °C, and 60 °C), time (20 min, 40 min, and 60 min), electrolyte concentration (0.5 M), voltage (9 V), and current intensity (0.600 A). A 3³ experimental design (three factors, three levels) was proposed, and mathematical models were obtained using general factorial design. The experimental design was used to determine the three most important variables in the optimal condition. A total of 27 tests were conducted using sulfuric acid electrolytic solutions, of which 12 samples were selected by the factorial design method, which simultaneously evaluates the effects of factors and their interactions in a single experiment. Measurement of porosity and oxide layer thickness was performed using scanning electron microscopy. The purity of the anodic layer formed was characterized using X-ray diffraction techniques with a vertical goniometer X-ray diffractometer. The electrochemical behavior is presented through potentiodynamic polarization curves for the anodic layer. A general factorial design and an analysis of variance (ANOVA) were conducted to establish the significant factors for layer thickness, grain size, and reaction rate. Finally, the best results and their parameters for each response are presented. Full article

(This article belongs to the Special Issue New Functional Coatings and Thin Films for Sensor and Green Energy Technologies)

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12 pages, 3152 KiB

Open AccessArticle

Controllable Crystallization of Perovskite Films during the Blade-Coating Fabrication Process for Efficient and Stable Solar Cells

by Zhaoyi Jiang, Jiaqi Li, Kun Li, Rui Zhang, Zhenxing Qin, Yufei Zhang, Boheng Wu, Qiang Ma, Yulong Zhang and Weijia Zhang

Coatings 2024, 14(9), 1113; https://doi.org/10.3390/coatings14091113 - 2 Sep 2024

Viewed by 2286

Abstract

The scalable production of high-quality perovskite thin films is pivotal for the industrialization of perovskite thin film solar cells. Consequently, the solvent system employed for the fabrication of large-area perovskite films via coating processes has attracted significant attention. In this study, a solvent [...] Read more.

The scalable production of high-quality perovskite thin films is pivotal for the industrialization of perovskite thin film solar cells. Consequently, the solvent system employed for the fabrication of large-area perovskite films via coating processes has attracted significant attention. In this study, a solvent system utilizing a volatile solvent as the primary reagent has been developed to facilitate the rapid nucleation of volatile compounds. While adding the liquid Lewis base dimethylformamide (DMF) can help to improve the microstructure of perovskite films, its slow volatilization renders the crystal growth process uncontrollable. Based on the solvent system containing DMF and ethanol (EtOH), introducing a small amount of NH₄Cl increases the proportion of the intermediate phase in the precursor films. This not only results in a controllable growth process for the perovskite crystals but also contributes to the improvement of the film microstructure. Under the simulated illumination (AM1.5, 1000 W/m²), the photoelectric conversion efficiency (PCE) of the inverted solar cells has been improved to 20.12%. Furthermore, after 500 hours of continuous illumination, the photovoltaic device can retain 95.6 % of the initial, indicating that the solvent system is suitable for the scalable fabrication of high-quality FAPbI₃ thin films. Full article

(This article belongs to the Special Issue New Functional Coatings and Thin Films for Sensor and Green Energy Technologies)

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11 pages, 3988 KiB

Open AccessArticle

Preparation of Highly Efficient and Stable All-Inorganic CsPbBr₃ Perovskite Solar Cells Using Pre-Crystallization Multi-Step Spin-Coating Method

by Yulong Zhang, Zhaoyi Jiang, Jincheng Li, Guanxiong Meng, Jiajun Guo and Weijia Zhang

Coatings 2024, 14(7), 918; https://doi.org/10.3390/coatings14070918 - 22 Jul 2024

Cited by 2 | Viewed by 1766

Abstract

All-inorganic CsPbBr₃ perovskite solar cells have garnered extensive attention in the photovoltaic domain due to their remarkable environmental stability. Nevertheless, CsPbBr₃ prepared using the conventional sequential deposition method suffers from issues such as inferior crystallinity, low phase purity, and poor film [...] Read more.

All-inorganic CsPbBr₃ perovskite solar cells have garnered extensive attention in the photovoltaic domain due to their remarkable environmental stability. Nevertheless, CsPbBr₃ prepared using the conventional sequential deposition method suffers from issues such as inferior crystallinity, low phase purity, and poor film morphology. Herein, we propose a pre-crystallization methodology by introducing a minute quantity of CsBr into the PbBr₂ precursor solution to generate a small amount of CsPb₂Br₅ crystals within the PbBr₂ film, leading to a porous PbBr₂ film with enhanced crystallinity. Under the influence of more pores and CsPb₂Br₅ crystals as nucleation sites for inducing growth, a CsPbBr₃ film with a larger crystal size, lower grain boundary density, stronger crystallinity, and higher phase purity is formed. Compared with untreated devices, photovoltaic devices prepared using the pre-crystallization method achieved a champion photovoltaic conversion efficiency (PCE) of 8.62%. Furthermore, pre-crystallized devices demonstrate higher stability than untreated ones and can still retain 94% of the original PCE after being exposed to air for 1000 h without encapsulating. Full article

(This article belongs to the Special Issue New Functional Coatings and Thin Films for Sensor and Green Energy Technologies)

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10 pages, 3887 KiB

Open AccessArticle

Controlling the Polymer Ink’s Rheological Properties to Form Single and Stable Droplet

by Zhonghui Du, Lu Zhang, Yushuang Du, Xiaoqing Wei, Xiang Du, Xinyan Lin, Jiajun Liu, Yani Huang, Yan Xue, Ning Zhao and Hongbo Liu

Coatings 2024, 14(5), 600; https://doi.org/10.3390/coatings14050600 - 10 May 2024

Viewed by 1120

Abstract

The formation of single and stable ink droplets is crucial for producing high-quality functional films in drop-on-demand (DOD) inkjet printing. The stability and singularity of droplet formation are significantly influenced by filament breakup behavior, governed by the rheological parameters of the ink formula. [...] Read more.

The formation of single and stable ink droplets is crucial for producing high-quality functional films in drop-on-demand (DOD) inkjet printing. The stability and singularity of droplet formation are significantly influenced by filament breakup behavior, governed by the rheological parameters of the ink formula. This study explores the droplet formation behavior of Poly3-hexylthiophene (P3HT) ink across various Weber numbers (We) and assesses the impact of the Z value on the formation of single ink droplets. Observations reveal that as the We number increases, droplet morphology transitions from single to double, and eventually to sputtered droplets. Results demonstrate that stable, single droplets form when the We number ≤ 13 and 12 < Z < 34, with a pulse duration of approximately 340 μs. When the We number exceeds 13, the molecular chains of P3HT stretch due to high hydrodynamic forces, resulting in the formation of unwanted satellite droplets. Full article

(This article belongs to the Special Issue New Functional Coatings and Thin Films for Sensor and Green Energy Technologies)

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12 pages, 4836 KiB

Open AccessArticle

Realizing Dual Functions through Y₂O₃ Modification to Enhance the Electrochemical Performance of LiNi_0.8Co_0.1Mn_0.1O₂ Material

by Xintao Wang, Feng Wang, Meiqi Zheng, Maohua Rong, Jiang Wang, Jianqiu Deng, Peng Liu and Daosheng Liu

Coatings 2024, 14(4), 443; https://doi.org/10.3390/coatings14040443 - 8 Apr 2024

Viewed by 1349

Abstract

In recent years, the remarkable energy density of high-nickel ternary materials has captured considerable attention. Nevertheless, the high-nickel ternary cathode material encounters several challenges, including cationic mixing, microcrack formation, poor cycling capability, and limited thermal stability. Coating, as a viable approach, proves to [...] Read more.

In recent years, the remarkable energy density of high-nickel ternary materials has captured considerable attention. Nevertheless, the high-nickel ternary cathode material encounters several challenges, including cationic mixing, microcrack formation, poor cycling capability, and limited thermal stability. Coating, as a viable approach, proves to be effective in enhancing the material properties. In this study, the LiNi_0.8Co_0.1Mn_0.1O₂ (NCM811) sample underwent a dry grinding process, followed by Y₂O₃ coating and subsequent sintering at varying temperatures. The microstructure, morphology, and electrochemical properties of the materials were meticulously examined, and the underlying mechanism of coating modification was meticulously explored. The outcomes demonstrate the attainment of dual coating and doping effects through Y₂O₃ modification. Y₂O₃ coating mitigates the direct interaction between the NCM811 surface and the electrolyte, thereby inhibiting undesired side reactions at the interface. Moreover, the Y element infiltrates the crystal structure, imparting stability at elevated sintering temperatures. Remarkably, the Y₂O₃-coated cathode materials exhibit significantly enhanced cycling stability, discharge capacity, and rate performance. These findings can provide novel insights that can be harnessed to improve the energy density cathode material of NCM811. Full article

(This article belongs to the Special Issue New Functional Coatings and Thin Films for Sensor and Green Energy Technologies)

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10 pages, 1469 KiB

Open AccessArticle

Crystalline Structure and Optical Properties of Cobalt Nickel Oxide Thin Films Deposited with a Pulsed Hollow-Cathode Discharge in an Ar+O₂ Gas Mixture

by Anna Kapran, Rainer Hippler, Harm Wulff, Jiri Olejnicek, Lenka Volfova, Aneta Pisarikova, Natalia Nepomniashchaia, Martin Cada and Zdenek Hubicka

Coatings 2024, 14(3), 319; https://doi.org/10.3390/coatings14030319 - 6 Mar 2024

Viewed by 1916

Abstract

Cobalt nickel oxide films are deposited on Si(111) or fluorine-doped tin-oxide-coated (FTO) glass substrates employing a pulsed hollow-cathode discharge. The hollow cathode is operated with argon gas flowing through the nozzle and with O₂ gas admitted to the vacuum chamber. Three different [...] Read more.

Cobalt nickel oxide films are deposited on Si(111) or fluorine-doped tin-oxide-coated (FTO) glass substrates employing a pulsed hollow-cathode discharge. The hollow cathode is operated with argon gas flowing through the nozzle and with O₂ gas admitted to the vacuum chamber. Three different cathode compositions (Co20Ni80, Co50Ni50, and Co80Ni20) are investigated. Deposited and annealed thin films are characterized by X-ray diffraction, infrared (Raman) spectroscopy, and ellipsometry. As-deposited films consist of a single mixed cobalt nickel oxide phase. Upon annealing at 600 °C, the mixed cobalt nickel oxide phase separates into two cystalline sub-phases which consist of cubic NiO and cubic Co₃O₄. Annealed films are investigated by spectroscopic ellipsometry and the optical bandgaps are determined. Full article

(This article belongs to the Special Issue New Functional Coatings and Thin Films for Sensor and Green Energy Technologies)

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