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Ternary metal sulfides (TMSs) have garnered significant attention as alternative electrode materials for rechargeable metal‐ion battery anodes and electrodes for electrochemical supercapacitors (SCs). With the escalating costs of lithium, research has shifted toward alternative sources like sodium‐ion batteries (NIBs) and potassium‐ion batteries (KIBs), offering cost‐effectiveness and greater natural abundance globally. However, pursuing suitable electrode materials beyond lithium‐ion batteries (LIBs), such as NIBs, KIBs, and SCs with enhanced energy and power density, remains a formidable challenge. In this context, TMSs demonstrate remarkable reversibility as NIB, KIB, and SC electrode materials, showcasing multi‐electron redox reactions, improved electronic conductivity, and higher theoretical capacities. Numerous research articles have highlighted the promising future of TMSs as electrodes for electrochemical energy conversion and storage (EECS). Nonetheless, practical applications are hindered by limitations, including structural stability during long‐standing cyclability, electronic conductivity, and scalability. This review systematically demonstrates how varying synthesis routes can tailor nanostructures and their influence on electrochemical activity. Additionally, an in‐depth literature survey is provided on the electrochemical performances of TMSs in NIBs, KIBs, and SCs and summarize recent advancements with the best available literature. Moreover, promising prospects and challenges are highlighted, expressing optimism that TMSs will emerge as pivotal electrodes for EECS. [ABSTRACT FROM AUTHOR]

Ongoing interest is focused on aqueous zinc ion batteries (ZIBs) for mass‐production energy storage systems as a result of their affordability, safety, and high energy density. Ensuring the stability of the electrode/electrolyte interface is of particular importance for prolonging the cycling ability to meet the practical requirements of rechargeable batteries. Zinc anodes exhibit poor cycle life and low coulombic efficiency, stemming from the severe dendrite growth, and irreversible byproducts such as H2 and inactive ZnO. Great efforts have recently been devoted to zinc anode protection for designing high‐performance ZIBs. However, the intrinsic origins of zinc plating/striping are poorly understood, which greatly delay its potential applications. Rather than focusing on battery metrics, this review delves deeply into the underlying science that triggers the deposition/dissolution of zinc ions. Furthermore, recent advances in modulating the zinc coordination environment, uniforming interfacial electric fields, and inducing zinc deposition are highlighted and summarized. Finally, perspectives and suggestions are provided for designing highly stable zinc anodes for the industrialization of the aqueous rechargeable ZIBs in the near future. [ABSTRACT FROM AUTHOR]

For the first time, a 3D Prussian blue analogue (PBA) with well-defined spatial organization is fabricated by using a nickel hydroxide array as a precursor. The nickel hydroxide arrays are synthesized in titanium foil and reacted with K3[Fe(CN)6]. The plate-like morphology of the nickel hydroxide is perfectly preserved and combined with abundant PBA nanocubes. After phosphidation at 350 °C, the obtained sample demonstrated excellent hydrogen evolution reaction (HER) activity in both acid and alkaline solutions to reach a current density of 10 mA cm-2 with an overpotential of only 70 and 121 mV, respectively. With an overpotential of 266 mV, it can reach a larger current density of 500 mA cm-2 in acid. The efficient HER activity of the obtained sample is mainly ascribed to its structural advantage with various active metal sites derived from the nickel hydroxide and PBA precursor. In addition, long-term stability measurements have verified the good performance of the obtained sample in acid and alkaline solutions. An increment of overpotential of only 8 and 9 mV is observed, in the acid and alkaline solutions respectively. Beyond these assets, it is supposed that the strategy to synthesize 3D PBA arrays from nickel hydroxide can be extended to other metal-organic frameworks arrays for more electrochemical applications. [ABSTRACT FROM AUTHOR]

Abstract: Developing facile preparation routes and atomic‐level characterization methods for single‐atom catalysts is highly desirable but still challenging. Herein, a general strategy is proposed to construct transition metal single atoms within 1D and 2D carbon supports. The carbon supports, typically graphene and carbon nanotubes, are coated with various transition metal‐containing bimetal hydroxides, followed by polydopamine coating and high‐temperature pyrolysis. X‐ray absorption fine structure spectroscopy measurements and simulations efficiently indicate that single atoms (Co, Fe, or Cu) are captured within the applied carbon supports, distinctively forming exclusive molecule‐type sites. As a proof‐of‐concept application, the obtained catalysts exhibit remarkable performance for electrochemical oxygen reduction reaction, even surpassing commercial Pt/C catalyst. The developed versatile route opens up new avenues for the design of carbon‐based catalysts with definite molecular active sites. The atomic‐level structural identifications provide significant guidance for mechanistic studies toward single‐atom catalysts. [ABSTRACT FROM AUTHOR]

Abstract: Electrochemical reduction of CO2 provides an opportunity to reach a carbon‐neutral energy recycling regime, in which CO2 emissions from fuel use are collected and converted back to fuels. The reduction of CO2 to CO is the first step toward the synthesis of more complex carbon‐based fuels and chemicals. Therefore, understanding this step is crucial for the development of high‐performance electrocatalyst for CO2 conversion to higher order products such as hydrocarbons. Here, atomic iron dispersed on nitrogen‐doped graphene (Fe/NG) is synthesized as an efficient electrocatalyst for CO2 reduction to CO. Fe/NG has a low reduction overpotential with high Faradic efficiency up to 80%. The existence of nitrogen‐confined atomic Fe moieties on the nitrogen‐doped graphene layer is confirmed by aberration‐corrected high‐angle annular dark‐field scanning transmission electron microscopy and X‐ray absorption fine structure analysis. The Fe/NG catalysts provide an ideal platform for comparative studies of the effect of the catalytic center on the electrocatalytic performance. The CO2 reduction reaction mechanism on atomic Fe surrounded by four N atoms (Fe–N4) embedded in nitrogen‐doped graphene is further investigated through density functional theory calculations, revealing a possible promotional effect of nitrogen doping on graphene. [ABSTRACT FROM AUTHOR]

Abstract: For the first time, a 3D Prussian blue analogue (PBA) with well‐defined spatial organization is fabricated by using a nickel hydroxide array as a precursor. The nickel hydroxide arrays are synthesized in titanium foil and reacted with K3[Fe(CN)6]. The plate‐like morphology of the nickel hydroxide is perfectly preserved and combined with abundant PBA nanocubes. After phosphidation at 350 °C, the obtained sample demonstrated excellent hydrogen evolution reaction (HER) activity in both acid and alkaline solutions to reach a current density of 10 mA cm−2 with an overpotential of only 70 and 121 mV, respectively. With an overpotential of 266 mV, it can reach a larger current density of 500 mA cm−2 in acid. The efficient HER activity of the obtained sample is mainly ascribed to its structural advantage with various active metal sites derived from the nickel hydroxide and PBA precursor. In addition, long‐term stability measurements have verified the good performance of the obtained sample in acid and alkaline solutions. An increment of overpotential of only 8 and 9 mV is observed, in the acid and alkaline solutions respectively. Beyond these assets, it is supposed that the strategy to synthesize 3D PBA arrays from nickel hydroxide can be extended to other metal–organic frameworks arrays for more electrochemical applications. [ABSTRACT FROM AUTHOR]

Photocatalysis is the most promising method for achieving artificial photosynthesis, but a bottleneck is encountered in finding materials that could efficiently promote the water splitting reaction. The nontoxicity, low cost, and versatility of photocatalysts make them especially attractive for this application. This study demonstrates that small amounts of α-Fe2O3 nanosheets can actively promote exfoliation of g-C3N4, producing 2D hybrid that exhibits tight interfaces and an all-solid-state Z-scheme junction. These nanostructured hybrids present a high H2 evolution rate >3 × 104 µmol g-1 h-1 and external quantum efficiency of 44.35% at λ = 420 nm, the highest value so far reported among the family of g-C3N4 photocatalysts. Besides effectively suppressing the recombination of electron-hole pairs, this Z-scheme junction also exhibits activity toward overall water splitting without any sacrificial donor. The proposed synthetic route for controlled production of 2D g-C3N4-based structures provides a scalable alternative toward the development of highly efficient and active photocatalysts. [ABSTRACT FROM AUTHOR]

Perovskite materials due to their exceptional photophysical properties are beginning to dominate the field of thin-film optoelectronic devices. However, one of the primary challenges is the processing-dependent variability in the properties, thus making it imperative to understand the origin of such variations. Here, it is discovered that the precursor solution aging time before it is cast into a thin film, is a subtle but a very important factor that dramatically affects the overall thin-film formation and crystallinity and therein factors such as grain growth, phase purity, surface uniformity, trap state density, and overall solar cell performance. It is shown that progressive aging of the precursor promotes efficient formation of larger seeds after the fast nucleation of a large density of small seeds. The hot-casting method then leads to the growth of large grains in uniform thin-films with excellent crystallinity validated using scanning microscopy images and X-ray diffraction patterns. The high-quality films cast from aged solution is ideal for thin-film photovoltaic device fabrication with reduced shunt current and good charge transport. This observation is a significant step toward achieving highly crystalline thin-films with reliability in device performance and establishes the subtle but dramatic effect of solution aging before fabricating perovskite thin-films. [ABSTRACT FROM AUTHOR]

2D atomic crystals such as single layer graphene (SLG) and hexagonal boron nitride (hBN) have been shown to be 'unexpectedly permeable' to hydrogen ions under ambient conditions with the proton conductivity rising exponentially with temperature. Here, the first successful addition of SLG made by a chemical vapor deposition (CVD) method is shown to an operational direct methanol fuel cell significantly enhancing the performance of the cell once the temperature is raised above 60 °C, the temperature at which the proton conductivity of SLG is higher than the Nafion membrane on which it is mounted. Above this temperature, the resistance to proton transport of the system is not affected by the graphene but the barrier properties of graphene inhibit methanol crossover. The performance of the fuel cell is shown to increase linearly with coverage of SLG above this temperature. Results show that the maximum power density is increased at 70 °C by 45% in comparison to the standard membrane electrode assembly without graphene. In addition, a membrane with CVD hBN shows enhanced performance across the entire temperature range due to better proton conductivity at lower temperatures. [ABSTRACT FROM AUTHOR]

3D CoNi2S4-graphene-2D-MoSe2 (CoNi2S4-G-MoSe2) nanocomposite is designed and prepared using a facile ultrasonication and hydrothermal method for supercapacitor (SC) applications. Because of the novel nanocomposite structures and resultant maximized synergistic effect among ultrathin MoSe2 nanosheets, highly conductive graphene and CoNi2S4 nanoparticles, the electrode exhibits rapid electron and ion transport rate and large electroactive surface area, resulting in its amazing electrochemical properties. The CoNi2S4-G-MoSe2 electrode demonstrates a maximum specific capacitance of 1141 F g-1, with capacitance retention of ≈108% after 2000 cycles at a high charge-discharge current density of 20 A g-1. As to its symmetric device, 109 F g-1 at a scan rate of 5 mV s-1 is exhibited. This pioneering work should be helpful in enhancing the capacitive performance of SC materials by designing nanostructures with efficient synergetic effects. [ABSTRACT FROM AUTHOR]

Batteries for high temperature applications capable of withstanding over 60 °C are still dominated by primary cells. Conventional rechargeable energy storage technologies which have exceptional performance at ambient temperatures employ volatile electrolytes and soft separators, resulting in catastrophic failure under heat. A composite electrolyte/separator is reported that holds the key to extend the capability of Li-ion batteries to high temperatures. A stoichiometric mixture of hexagonal boron nitride, piperidinium-based ionic liquid, and a lithium salt is formulated, with ionic conductivity reaching 3 mS cm−1, electrochemical stability up to 5 V and extended thermal stability. The composite is used in combination with conventional electrodes and demonstrates to be stable for over 600 cycles at 120 °C, with a total capacity fade of less than 3%. The ease of formulation along with superior thermal and electrochemical stability of this system extends the use of Li-ion chemistries to applications beyond consumer electronics and electric vehicles. [ABSTRACT FROM AUTHOR]

Batteries have become fundamental building blocks for the mobility of modern society. Continuous development of novel battery chemistries and electrode materials has nourished progress in building better batteries. Simultaneously, novel device form factors and designs with multi-functional components have been proposed, requiring batteries to not only integrate seamlessly to these devices, but to also be a multi-functional component for a multitude of applications. Thus, in the past decade, along with developments in the component materials, the focus has been shifting more and more towards novel fabrication processes, unconventional configurations, and additional functionalities. This work attempts to critically review the developments with respect to emerging electrochemical energy storage configurations, including, amongst others, paintable, transparent, flexible, wire or cable shaped, ultra-thin and ultra-thick configurations, as well as hybrid energy storage-conversion, or graphene-incorporated batteries and supercapacitors. The performance requirements are elaborated together with the advantages, but also the limitations, with respect to established electrochemical energy storage technologies. Finally, challenges in developing novel materials with tailored properties that would allow such configurations, and in designing easier manufacturing techniques that can be widely adopted are considered. [ABSTRACT FROM AUTHOR]

Aligned carbon nanotube (CNT) forests filled with a dehydrated polymer electrolyte are used to fabricate flexible solid state supercapacitors (SSCs) for multifunctional structural-electronic applications. Local stiffness measurements on the composite electrodes determined through nano­indentation showed an 80% increase over the neat solid polymer electrolyte matrix. Electrochemical properties are monitored as a function of average tensile strain in the SSCs. Galvanostatic charge-discharge tests with in situ microtensile testing on SSCs are used to show a 10% increase in the specific capacitance through the elastic region of the composite. The increase in capacitance is partly attributed to the enhanced double layer interaction that results from the partial alignment of the polymer electrolyte chains at the electrode-electrolyte interface. When soaked in 1 m sulfuric acid, the specific capacitance of the CNT-polymer electrolyte reached approximately 72 F g-1 at 60 °C. [ABSTRACT FROM AUTHOR]