Physical Vapor Deposition in Solid-State Battery Development: From Materials to Devices

The Application Progress of Nonthermal Plasma Technology in the Modification of Bone Implant Materials

With the accelerating trend of global aging, bone damage caused by orthopedic diseases, such as osteoporosis and fractures, has become a shared international event. Traffic accidents, high-altitude falls, and other incidents are increasing daily, and the demand for bone implant treatment is also growing. Although extensive research has been conducted in the past decade to develop medical implants for bone regeneration and healing of body tissues, due to their low biocompatibility, weak bone integration ability, and high postoperative infection rates, pure titanium alloys, such as Ti-6A1-4V and Ti-6A1-7Nb, although widely used in clinical practice, have poor induction of phosphate deposition and wear resistance, and Ti-Zr alloy exhibits a lack of mechanical stability and processing complexity. In contrast, the Ti-Ni alloy exhibits toxicity and low thermal conductivity. Nonthermal plasma (NTP) has aroused widespread interest in synthesizing and modifying implanted materials. More and more researchers are using plasma to modify target catalysts such as changing the dispersion of active sites, adjusting electronic properties, enhancing metal carrier interactions, and changing their morphology. NTP provides an alternative option for catalysts in the modification processes of oxidation, reduction, etching, coating, and doping, especially for materials that cannot tolerate thermodynamic or thermosensitive reactions. This review will focus on applying NTP technology in bone implant material modification and analyze the overall performance of three common types of bone implant materials, including metals, ceramics, and polymers. The challenges faced by NTP material modification are also discussed.

Inorganic Sodium Solid Electrolytes: Structure Design, Interface Engineering and Application

All-solid-state sodium batteries (ASSSBs) are particularly attractive for large-scale energy storage and electric vehicles due to their exceptional safety, abundant resource availability, and cost-effectiveness. The growing demand for ASSSBs underscores the significance of sodium solid electrolytes; However, the existed challenges of sodium solid electrolytes hinder their practical application despite continuous research efforts. Herein, recent advancements and the challenges for sodium solid electrolytes from material to battery level are reviewed. The in-depth understanding of their fundamental properties, synthesis techniques, crystal structures and recent breakthroughs is presented. Moreover, critical challenges on inorganic sodium solid electrolytes are emphasized, including the imperative need to enhance ionic conductivity, fortifying interfacial compatibility with anode/cathode materials, and addressing dendrite formation issues. Finally, potential applications of these inorganic sodium solid electrolytes are explored in ASSSBs and emerging battery systems, offering insights into future research directions.

Magnesium Magic: State-of-the-Art Nanocrystalline Materials Paving the Way for Hydrogen Storage

Hydrogen has been regarded as a promising alternative to traditional fossil fuels, presenting itself as a viable and environmentally friendly energy choice. The design and fabrication of highly efficient hydrogen storage materials is crucial to the wide utilization of hydrogen-based technologies. Magnesium-based nanocrystalline materials have received significant interest in the field of hydrogen storage due to their remarkable hydrogen storage capabilities and release efficiency. This review emphasizes on the most useful techniques including vapor deposition, sol-gel synthesis, electrochemical deposition, magnetron sputtering, and template-assisted approaches used for the fabrication of Magnesium-based nanocrystalline hydrogen storage materials (Mg-NHSMs), stressing their advantages, limitations, and recent advancements. These cutting-edge techniques demonstrate their significance in offering useful insights into the performance of Mg-NHSMs. Further, this review describes various applications of Mg-NHSMs. In addition, this review highlights the conclusion and future perspectives on the improvement of magnesium based nanocrystalline materials for efficient hydrogen storage.

Development of plasma technology for the preparation and modification of energy storage materials

The development of energy storage material technologies stands as a decisive measure in optimizing the structure of clean and low-carbon energy systems. The remarkable activity inherent in plasma technology imbues it with distinct advantages in surface modification, functionalization, synthesis, and interface engineering of materials. This review systematically expounds upon the principles, classifications, and application scenarios of plasma technology, while thoroughly discussing its unique merits in the realm of modifying electrode materials, solid-state electrolytes, and conductive carbon materials, which are widely used in lithium-ion batteries, sodium ion batteries, metal air batteries and other fields. Finally, considering the existing constraints associated with lithium-ion batteries, some application prospects of plasma technology in the energy storage field are suggested. This work is of great significance for the development of clean plasma technology in the field of energy storage.

A Review on Engineering Design for Enhancing Interfacial Contact in Solid-State Lithium-Sulfur Batteries

The utilization of solid-state electrolytes (SSEs) presents a promising solution to the issues of safety concern and shuttle effect in Li-S batteries, which has garnered significant interest recently. However, the high interfacial impedances existing between the SSEs and the electrodes (both lithium anodes and sulfur cathodes) hinder the charge transfer and intensify the uneven deposition of lithium, which ultimately result in insufficient capacity utilization and poor cycling stability. Hence, the reduction of interfacial resistance between SSEs and electrodes is of paramount importance in the pursuit of efficacious solid-state batteries. In this review, we focus on the experimental strategies employed to enhance the interfacial contact between SSEs and electrodes, and summarize recent progresses of their applications in solid-state Li-S batteries. Moreover, the challenges and perspectives of rational interfacial design in practical solid-state Li-S batteries are outlined as well. We expect that this review will provide new insights into the further technique development and practical applications of solid-state lithium batteries.

Biomass-derived carbon materials for vanadium redox flow battery: From structure to property

Biomass-derived carbon (BDC) materials are suitable as electrode or catalyst materials for vanadium redox flow battery (VRFB), owing to the characteristics of vast material sources, environmental friendliness, and multifarious structures. A timely and comprehensive review of the structure and property significantly facilitates the development of BDC materials. Here, the paper starts with the preparation of biomass materials, including carbonization and activation. It is designed to summarize the lastest developments in BDC materials of VRFB in four different structural dimensions from zero dimension (0D) to three dimension (3D). Every dimension begins with meticulously selected examples to introduce the structural characteristics of materials and then illustrates the improved performance of the VRFB due to the structure. Simultaneously, challenges, solutions, and prospects are indicated for the further development of BDC materials. Overall, this review will help researchers select excellent strategies for the fabrication of BDC materials, thereby facilitating the use of BDC materials in VRFB design.

Effect of Substrates on the Physicochemical Properties of Li7La3Zr2O12 Films Obtained by Electrophoretic Deposition

Thin film technology of lithium-ion solid electrolytes should be developed for the creation of all-solid-state power sources. Solid electrolytes of the Li7La3Zr2O12 (LLZ) family are one of the promising membranes for all-solid-state batteries. LLZ films were obtained by electrophoretic deposition on Ti, Ni and steel substrates. The influence of different metal substrates on microstructure, phase composition and conductivity of the LLZ films after their heat treatment was studied. It was shown that the annealing of dried LLZ films in an Ar atmosphere leads to the transition from tetragonal modification to a low-temperature cubic structure. It was established that an impurity phase (Li2CO3) was not observed for LLZ films deposited on Ti foil after heat treatment, in contrast to films deposited on Ni and steel substrates. The highest lithium-ion conductivity values were achieved for the LLZ films annealed at 300 °C, 1.1 × 10-8 S cm-1 (at 100 °C) and 1.0 × 10-6 S cm-1 (at 200 °C).

Monolithically-stacked thin-film solid-state batteries

The power capability of Li-ion batteries has become increasingly limiting for the electrification of transport on land and in the air. The specific power of Li-ion batteries is restricted to a few thousand W kg^-1 due to the required cathode thickness of a few tens of micrometers. We present a design of monolithically-stacked thin-film cells that has the potential to increase the power ten-fold. We demonstrate an experimental proof-of-concept consisting of two monolithically stacked thin-film cells. Each cell consists of a silicon anode, a solid-oxide electrolyte, and a lithium cobalt oxide cathode. The battery can be cycled for more than 300 cycles between 6 and 8 V. Using a thermo-electric model, we predict that stacked thin-film batteries can achieve specific energies >250 Wh kg^-1 at C-rates above 60, resulting in a specific power of tens of kW kg^-1 needed for high-end applications such as drones, robots, and electric vertical take-off and landing aircrafts.

Vanadium Oxide: Phase Diagrams, Structures, Synthesis, and Applications

Vanadium oxides with multioxidation states and various crystalline structures offer unique electrical, optical, optoelectronic and magnetic properties, which could be manipulated for various applications. For the past 30 years, significant efforts have been made to study the fundamental science and explore the potential for vanadium oxide materials in ion batteries, water splitting, smart windows, supercapacitors, sensors, and so on. This review focuses on the most recent progress in synthesis methods and applications of some thermodynamically stable and metastable vanadium oxides, including but not limited to V₂O₃, V₃O₅, VO₂, V₃O₇, V₂O₅, V₂O₂, V₆O₁₃, and V₄O₉. We begin with a tutorial on the phase diagram of the V-O system. The second part is a detailed review covering the crystal structure, the synthesis protocols, and the applications of each vanadium oxide, especially in batteries, catalysts, smart windows, and supercapacitors. We conclude with a brief perspective on how material and device improvements can address current deficiencies. This comprehensive review could accelerate the development of novel vanadium oxide structures in related applications.

Recent Advances in One-Dimensional Micro/Nanomotors: Fabrication, Propulsion and Application

Due to their tiny size, autonomous motion and functionalize modifications, micro/nanomotors have shown great potential for environmental remediation, biomedicine and micro/nano-engineering. One-dimensional (1D) micro/nanomotors combine the characteristics of anisotropy and large aspect ratio of 1D materials with the advantages of functionalization and autonomous motion of micro/nanomotors for revolutionary applications. In this review, we discuss current research progress on 1D micro/nanomotors, including the fabrication methods, driving mechanisms, and recent advances in environmental remediation and biomedical applications, as well as discuss current challenges and possible solutions. With continuous attention and innovation, the advancement of 1D micro/nanomotors will pave the way for the continued development of the micro/nanomotor field.

Ultrasonic Measurement of Axial Preload in High-Frequency Nickel-Based Superalloy Smart Bolt

A high-frequency, piezoelectric thin-film sensor was successfully deposited on a nickel-based superalloy bolt by radio frequency magnetron sputtering to develop a smart, nickel-based superalloy bolt. Ultrasonic response characterization, high accuracy, and repeatability of ultrasonic measurement of axial preload in nickel-based superalloy smart bolts are reported here and were fully demonstrated. The axial preload in the nickel-based superalloy smart bolt was directly measured by the bi-wave method (TOF ratio between transverse and longitudinal-mode waves) without using the traditional integration of a longitudinal and shear transducer. A model concerning the bolt before and after tensioning was established to demonstrate the propagation and displacement distribution of the ultrasonic waves inside a nickel-based superalloy smart bolt. The measured A-scan signal presented significantly favorable features including a mixture of transverse and longitudinal mode waves, a pure and broad frequency spectrum which peaked at 17.14 MHz, and high measurement accuracy below 3% for tension of 4 kN-20 kN. For the temporal ultrasonic signal, the measurement envelopes were narrower than for the counterpart of the simulation, justifying the 'filtration' advantage of the high-frequency sensor. Both the TOF change of the single longitudinal-mode wave and the TOF ratio between transverse- and longitudinal-mode waves increased linearly with preload force in the range of 0 kN to 20 kN. Compared with the commercial piezoelectric probe, the proposed probe, based on the combination of a high-frequency, piezoelectric thin-film sensor and a magnetically mounted transducer connector, exhibited high tolerance to temperatures as high as 320 °C and high repeatability free from some interference factors such as bolt detection position change and couplant layer thickness. The results indicate that this system is a promising axial preload measurement system for high-temperature fasteners and connectors, and the proposed sensor is a practical, high-frequency ultrasonic sensor for non-destructive testing.

Growth Parameters and Diffusion Barriers for Functional High-Voltage Thin-Film Batteries Based on Spinel LiNi0.5Mn1.5O4 Cathodes

Cobalt-free spinel LiNi_0.5Mn_1.5O₄ is one of the most promising and environmentally friendly cathodes, based on its high specific theoretical capacity (147 mAh·g^-1) and high electrochemical potential (4.7 V vs Li⁺/Li), as well as good electronic and Li-ion conductivities. In this work, we present the fabrication of LiNi_0.5Mn_1.5O₄ thin-film cathodes deposited by the industrially scalable AC magnetron sputtering technique on functional and cost-effective stainless steel current collectors. This is the first step toward battery downscaling, envisioning the fabrication of compact microbatteries for low-power energy supply. The thin-film strategy is crucial also for solid electrolyte fabrication that will allow the integration of high-energy-density batteries while overcoming most of the current battery challenges. In this work, the effect of film thickness on the material's electrochemical performance is discussed, correlating the observed structural and morphological evolution with the final electrochemical response. Moreover, the effect of iron diffusion from the current collector substrate into the cathode film is analyzed. The addition of a stable CrN barrier layer in between the substrate and the film is proposed to prevent Fe diffusion, with a direct positive influence on the electrochemical behavior. All in all, the obtained results will facilitate the practical implementation of LiNi_0.5Mn_1.5O₄ thin films as high-voltage cathodes in functional cost-effective microbatteries.

All-Solid-State Thin Film μ-Batteries for Microelectronics

Continuous advances in microelectronics and micro/nanoelectromechanical systems enable the use of microsized energy storage devices, namely solid-state thin-film μ-batteries. Different from the current button batteries, the μ-battery can directly be integrated on microchips forming a very compact "system on chip" since no liquid electrolyte is used in the μ-battery. The all-solid-state battery (ASSB) that uses solid-state electrolyte has become a research trend because of its high safety and increased capacity. The solid-state thin-film μ-battery belongs to the family of ASSB but in a small format. However, a lot of scientific and technical issues and challenges are to be resolved before its real application, including the ionic conductivity of the solid-state electrolyte, the electrical conductivity of the electrode, integration technologies, electrochemical-induced strain, etc. To achieve this goal, understanding the processing of thin films and fundamentals of ion transfer in the solid-state electrolytes and hence in the μ-batteries becomes utmost important. This review therefore focuses on solid-state ionics and provides inside of ion transportation in the solid state and effects of chemistry on electrochemical behaviors and proposes key technology for processing of the μ-battery.