Recent Progresses and Development of Advanced Atomic Layer Deposition towards High-Performance Li-Ion Batteries

Atomic Layer Deposition-A Versatile Toolbox for Designing/Engineering Electrodes for Advanced Supercapacitors

Atomic layer deposition (ALD) has become the most widely used thin-film deposition technique in various fields due to its unique advantages, such as self-terminating growth, precise thickness control, and excellent deposition quality. In the energy storage domain, ALD has shown great potential for supercapacitors (SCs) by enabling the construction and surface engineering of novel electrode materials. This review aims to present a comprehensive outlook on the development, achievements, and design of advanced electrodes involving the application of ALD for realizing high-performance SCs to date, as organized in several sections of this paper. Specifically, this review focuses on understanding the influence of ALD parameters on the electrochemical performance and discusses the ALD of nanostructured electrochemically active electrode materials on various templates for SCs. It examines the influence of ALD parameters on electrochemical performance and highlights ALD's role in passivating electrodes and creating 3D nanoarchitectures. The relationship between synthesis procedures and SC properties is analyzed to guide future research in preparing materials for various applications. Finally, it is concluded by suggesting the directions and scope of future research and development to further leverage the unique advantages of ALD for fabricating new materials and harness the unexplored opportunities in the fabrication of advanced-generation SCs.

On the Durability of Protective Titania Coatings on High-Voltage Spinel Cathodes

TiO2 -coating of LiNi0.5-x Mn1.5+x O4 (LNMO) by atomic layer deposition (ALD) has been studied as a strategy to stabilize the cathode/electrolyte interface and mitigate transition metal (TM) ion dissolution. The TiO2 coatings were found to be uniform, with thicknesses estimated to 0.2, 0.3, and 0.6 nm for the LNMO powders exposed to 5, 10, and 20 ALD cycles, respectively. While electrochemical characterization in half-cells revealed little to no improvement in the capacity retention neither at 20 nor at 50 °C, improved capacity retention and coulombic efficiencies were demonstrated for the TiO2 -coated LNMO in LNMO||graphite full-cells at 20 °C. This improvement in cycling stability could partly be attributed to thinner cathode electrolyte interphase on the TiO2 -coated samples. Additionally, energy-dispersive X-ray spectroscopy revealed a thinner solid electrolyte interphase on the graphite electrode cycled against TiO2 -coated LNMO, indicating retardation of TM dissolution by the TiO2 -coating.

Enhanced Cyclability of Cr8O21 Cathode for PEO-Based All-Solid-State Lithium-Ion Batteries by Atomic Layer Deposition of Al2O3

Cr₈O₂₁ can be used as the cathode material in all-solid-state batteries with high energy density due to its high reversible specific capacity and high potential plateau. However, the strong oxidation of Cr₈O₂₁ leads to poor compatibility with polymer-based solid electrolytes. Herein, to improve the cycle performance of the battery, Al₂O₃ atomic layer deposition (ALD) coating is applied on Cr₈O₂₁ cathodes to modify the interface between the electrode and the electrolyte. X-ray photoelectron spectroscopy, scanning electron microscope, transmission electron microscope, and Fourier transform infrared spectroscopy, etc., are used to estimate the morphology of the ALD coating and the interface reaction mechanism. The electrochemical properties of the Cr₈O₂₁ cathodes are investigated. The results show that the uniform and dense Al₂O₃ layer not only prevents the polyethylene oxide from oxidization but also enhances the lithium-ion transport. The 12-ALD-cycle-coated electrode with approximately 4 nm Al₂O₃ layer displays the optimal cycling performance, which delivers a high capacity of 260 mAh g⁻¹ for the 125th cycle at 0.1C with a discharge-specific energy of 630 Wh kg⁻¹.

Durable Lithium/Selenium Batteries Enabled by the Integration of MOF-Derived Porous Carbon and Alucone Coating

Lithium-selenium (Li-Se) batteries are a promising energy storage system in electric vehicles due to their high capacity and good kinetics. However, the shuttle effect issue, caused by polyselenide dissolution from the Se cathode, has hampered the development of Li-Se batteries. Herein, we developed a facile preparation of porous carbon from a metal-organic framework (MOF) to confine Se (Se/CZIF) and protect the Se/CZIF composite with an alucone coating by molecular layer deposition (MLD). The optimal alucone coated Se/CZIF cathode prepared exhibits a one-step reversible charge/discharge process in the carbonate electrolytes. The inhibition of polyselenide dissolution is credited with the improved electrochemical performance, formation of thin and stable solid electrolyte interphase (SEI) layers, and a reduction in charge transfer resistance, thus improving the overall performance of Li-Se batteries.

Surface modification and functionalization of powder materials by atomic layer deposition: a review

Powder materials are a class of industrial materials with many important applications. In some circumstances, surface modification and functionalization of these materials are essential for achieving or enhancing their expected performances. However, effective and precise surface modification of powder materials remains a challenge due to a series of problems such as high surface area, diffusion limitation, and particle agglomeration. Atomic layer deposition (ALD) is a cutting-edge thin film coating technology traditionally used in the semiconductor industry. ALD enables layer by layer thin film growth by alternating saturated surface reactions between the gaseous precursors and the substrate. The self-limiting nature of ALD surface reaction offers angstrom level thickness control as well as exceptional film conformality on complex structures. With these advantages, ALD has become a powerful tool to effectively fabricate powder materials for applications in many areas other than microelectronics. This review focuses on the unique capability of ALD in surface engineering of powder materials, including recent advances in the design of ALD reactors for powder fabrication, and applications of ALD in areas such as stabilization of particles, catalysts, energetic materials, batteries, wave absorbing materials and medicine. We intend to show the versatility and efficacy of ALD in fabricating various kinds of powder materials, and help the readers gain insights into the principles, methods, and unique effects of powder fabrication by ALD.

Atomic/molecular layer deposition for energy storage and conversion

Energy storage and conversion systems, including batteries, supercapacitors, fuel cells, solar cells, and photoelectrochemical water splitting, have played vital roles in the reduction of fossil fuel usage, addressing environmental issues and the development of electric vehicles. The fabrication and surface/interface engineering of electrode materials with refined structures are indispensable for achieving optimal performances for the different energy-related devices. Atomic layer deposition (ALD) and molecular layer deposition (MLD) techniques, the gas-phase thin film deposition processes with self-limiting and saturated surface reactions, have emerged as powerful techniques for surface and interface engineering in energy-related devices due to their exceptional capability of precise thickness control, excellent uniformity and conformity, tunable composition and relatively low deposition temperature. In the past few decades, ALD and MLD have been intensively studied for energy storage and conversion applications with remarkable progress. In this review, we give a comprehensive summary of the development and achievements of ALD and MLD and their applications for energy storage and conversion, including batteries, supercapacitors, fuel cells, solar cells, and photoelectrochemical water splitting. Moreover, the fundamental understanding of the mechanisms involved in different devices will be deeply reviewed. Furthermore, the large-scale potential of ALD and MLD techniques is discussed and predicted. Finally, we will provide insightful perspectives on future directions for new material design by ALD and MLD and untapped opportunities in energy storage and conversion.

Molecular-layer-deposited tincone: a new hybrid organic-inorganic anode material for three-dimensional microbatteries

A new hybrid organic-inorganic film, tincone, was developed by using molecular layer deposition (MLD), and exhibited high electrochemical activity toward Li storage. The self-limiting growth behavior, high uniformity on various substrates and good Li-storage performance make tincone a very promising new anode material for 3D microbatteries.

Advanced Thin Film Cathodes for Lithium Ion Batteries

Binder-free thin film cathodes have become a critical basis for advanced high-performance lithium ion batteries for lightweight device applications such as all-solid-state batteries, portable electronics, and flexible electronics. However, these thin film electrodes generally require modifications to improve the electrochemical performance. This overview summarizes the current modification approaches on thin film cathodes, where the approaches can be classified as single-phase nanostructure designs and multiphase nanocomposite designs. Recent representative advancements of different modification approaches are also highlighted. Besides, this review discusses the existing challenges regarding the thin film cathodes. The review also discusses the future research directions and needs towards future advancement in thin film cathode designs for energy storage needs in advanced portable and personal electronics.

Interface Engineering of an RGO/MoS2/Pd 2D Heterostructure for Electrocatalytic Overall Water Splitting in Alkaline Medium

To achieve sustainable production of H₂ at ambient temperature, highly active and stable electrocatalysts are the key to water splitting technology commercialization for hydrogen and oxygen production to replace Pt and IrO₂ catalysts. Herein, a modified interface of palladium (Pd) and reduced graphene oxide (RGO)-supported molybdenum disulfide (MoS₂) prepared by the solvothermal followed by chemical reduction method is established, in which abundant interfaces are formed. The phase structure, composition, chemical coupling, and morphology of the two-dimensional nanostructures are established by X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy, respectively. A structural phase transformation in MoS₂ is observed from trigonal (2H) to octahedral (1T) by virtue of Pd addition, which is well established from XRD, Raman, and XPS studies. For oxygen evolution reaction (OER) and hydrogen evolution reaction (HER), the RGO/MoS₂/Pd (RMoS₂Pd) catalyst exhibits extremely low overpotential (245 mV for OER and 86 mV for HER) to achieve benchmark current density, with small values of Tafel slope (42 mV dec^-1 for OER and 35.9 mV dec^-1 for HER) and charge transfer resistance. The quantitative study shows the hydrogen production rate of RMoS₂Pd of 335 μmol h^-1 with excellent stability in alkaline medium, which is superior to MoS₂, RMoS₂, and MoS₂Pd. The improved performance of RMoS₂Pd is attributed to the combined synergetic effect of 1T MoS₂, sulfur vacancy, and conducting RGO sheet, which efficiently accelerate the overall electrochemical water splitting.

The Use of the TMA as Stabilizing Reagent for the Li-O System Obtained by Atomic Layer Deposition

Lithium-oxygen thin films were deposited by atomic layer deposition (ALD) on the surface of silicon and stainless-steel using lithium bis (trimethylsilyl) amide (LiHMDS) and different counter-reagents (water, ozone, oxygen plasma). The deposited films were non-stable at storage in the air atmosphere. Results of scanning electron microscopy showed that films show a tendency to crystallization and peeling from the substrate surface. X-ray photoelectron spectroscopy and time-of-flight secondary ion mass spectroscopy revealed that films mainly consist of LiOH/Li2CO3. Coating the surface of lithium-oxygen films with an aluminum oxide layer using the ALD trimethylaluminum (TMA) and water as precursors did not lead to a significant improvement in stability. Nevertheless, the stable films can be obtained using ALD supercycles consisting of sequential pulsing of LiHMDS-water-TMA-water at 250°C.