Xiaojian Wang

Bio: Xiaojian Wang is an academic researcher from Jinan University. The author has contributed to research in topics: Corrosion & Alloy. The author has an hindex of 26, co-authored 79 publications receiving 5157 citations. Previous affiliations of Xiaojian Wang include Brookhaven National Laboratory & Deakin University.

High Energy Density Metal-Air Batteries: A Review

Abstract: In the last few decades, there are some exciting developments in the field of lithium (Li)-ion batteries from small portable devices to large power system such as electric vehicles (EVs). However, the maximum energy density of lithium-ion batteries is insufficient for the extended range of EVs propulsion. On the other hand, metal-air batteries have a greater power storage capacity, a few times more than the best performing lithium-ion batteries. Mechanically rechargeable zinc (Zn)-, magnesium (Mg)-, and aluminum (Al)-air batteries are receiving increasing attention, due to the advantages of using safe, low cost and abundant materials. If successfully developed, these batteries could provide an energy source for EVs comparing that of gasoline in terms of usable energy density. Nevertheless, there are still numerous scientific and technical challenges that must be overcome, if this alluring promise can be turned into reality. This paper provides a comprehensive overview of recent advances and challenges of metal air batteries from various elements, including air cathode, electrolyte, and anode. In addition, this review outlines the fundamental principles and understanding of the electrochemical reactions in the areas of lithium-air batteries. Finally, a summary of future research directions in the field of the metal-air batteries is provided.

Electrochemically Induced High Capacity Displacement Reaction of PEO/MoS2/Graphene Nanocomposites with Lithium

Abstract: MoS2/PEO/graphene composite is successfully prepared and the discharge mechanism of MoS2 as an anode material for Li-ion batteries has been investigated systematically in this work The simultaneous formation of Li2S and Mo at deep discharge depth has been shown for the first time The deposition of Mo metal with Li residing on the defects after the first discharge increases the intrinsic electronic conductivity of the electrode leading to a superior cycling stability for over 185 cycles After the first discharge the amorphous Mo matrix allows a large amount of Li+ ions to repeatedly deposit and being oxidized during cycling while the transition between Li2S and S contribute to the capacity above 20 V The interactions between as-formed Mo and S prevents the dissolution of the intermediate polysulfide thus providing clues to immobilize the soluble species in a Li-S battery Excellent rate performances are achieved in this MoS2/PEO/graphene composite indicating a fast diffusion path of Li+ ions existing not only in the bulk material but also in the interface between the electrode and the electrolyte

Combining In Situ Synchrotron X‐Ray Diffraction and Absorption Techniques with Transmission Electron Microscopy to Study the Origin of Thermal Instability in Overcharged Cathode Materials for Lithium‐Ion Batteries

Abstract: The thermal instability of the cathode materials in lithium-ion batteries is an important safety issue, requiring the incorporation of several approaches to prevent thermal runaway and combustion. Systematic studies, using combined well-defined in situ techniques, are crucial to obtaining in-depth understanding of the structural origin of this thermal instability in overcharged cathode materials. Here time-resolved X-ray diffraction, X-ray absorption, mass spectroscopy, and high-resolution transmission electron microscopy during heating are combined to detail the structural changes in overcharged LixNi0.8Co0.15Al0.05O2 and LixNi1/3Co1/3Mn1/3O2 cathode materials. By employing these several techniques in concert, various aspects of the structural changes are investigated in these two materials at an overcharged state; these include differences in phase-distribution after overcharge, phase nucleation and propagation during heating, the preferred atomic sites and migration paths of Ni, Co, and Mn, and their individual contributions to thermal stability, together with measuring the oxygen release that accompanies these structural changes. These results provide valuable guidance for developing new cathode materials with improved safety characteristics.

Additive manufacturing (3D printing): A review of materials, methods, applications and challenges

Abstract: Freedom of design, mass customisation, waste minimisation and the ability to manufacture complex structures, as well as fast prototyping, are the main benefits of additive manufacturing (AM) or 3D printing. A comprehensive review of the main 3D printing methods, materials and their development in trending applications was carried out. In particular, the revolutionary applications of AM in biomedical, aerospace, buildings and protective structures were discussed. The current state of materials development, including metal alloys, polymer composites, ceramics and concrete, was presented. In addition, this paper discussed the main processing challenges with void formation, anisotropic behaviour, the limitation of computer design and layer-by-layer appearance. Overall, this paper gives an overview of 3D printing, including a survey on its benefits and drawbacks as a benchmark for future research and development.

25th Anniversary Article: MXenes: A New Family of Two‐Dimensional Materials

Abstract: Recently a new, large family of two-dimensional (2D) early transition metal carbides and carbonitrides, called MXenes, was discovered. MXenes are produced by selective etching of the A element from the MAX phases, which are metallically conductive, layered solids connected by strong metallic, ionic, and covalent bonds, such as Ti2AlC, Ti3AlC2, and Ta4AlC3. MXenes ­combine the metallic conductivity of transition metal carbides with the hydrophilic nature of their hydroxyl or oxygen terminated surfaces. In essence, they behave as “conductive clays”. This article reviews progress—both ­experimental and theoretical—on their synthesis, structure, properties, intercalation, delamination, and potential applications. MXenes are expected to be good candidates for a host of applications. They have already shown promising performance in electrochemical energy storage systems. A detailed outlook for future research on MXenes is also presented.

Recent Advances in Ultrathin Two-Dimensional Nanomaterials

Abstract: Since the discovery of mechanically exfoliated graphene in 2004, research on ultrathin two-dimensional (2D) nanomaterials has grown exponentially in the fields of condensed matter physics, material science, chemistry, and nanotechnology. Highlighting their compelling physical, chemical, electronic, and optical properties, as well as their various potential applications, in this Review, we summarize the state-of-art progress on the ultrathin 2D nanomaterials with a particular emphasis on their recent advances. First, we introduce the unique advances on ultrathin 2D nanomaterials, followed by the description of their composition and crystal structures. The assortments of their synthetic methods are then summarized, including insights on their advantages and limitations, alongside some recommendations on suitable characterization techniques. We also discuss in detail the utilization of these ultrathin 2D nanomaterials for wide ranges of potential applications among the electronics/optoelectronics, electrocat...