Advanced Sustainable Systems最新文献

Mixed phase of monoclinic manganese tungsten oxide (MnWO₄) and cubic hydroxyl manganese tungsten oxide (Mn₄W₆O₂₁ · (OH)₂) thin film with cuboidal and flower analogues cocktail surface architecture has been explored through an unadorned, cost-efficient, and low-temperature chemical approach, well confirmed through HR-TEM and SAED. The polarons formed due to the electronic structure of manganese tungsten oxide contribute to p-type conductivity via a hopping mechanism and enhance pseudocapacitive faradic reactions. Hybridization of manganese 3d orbitals with tungsten 5d orbitals and oxygen 2p orbitals leads to superior electrochemical performance, which is confirmed by first-principles density-functional theory studies for MnWO₄ and two formula units Mn₄W₆O₂₁. The mixed phase hydroxylated tungsten oxide with hydrophilic surface with contact angle of 29.10°, enables superior electrochemical performance, exhibiting a voltage window of 0.97 V with specific capacitance of 1036.77 F · g⁻¹ (areal 736.11 mF · cm⁻²) at scan rate of 2 mV · s⁻¹, in aqueous KOH electrolyte. Charge storage mechanisms, inclusive of surface capacitive and diffusion-controlled, are well quantified. Designed asymmetric flexible solid-state supercapacitor embedded with PVA − LiClO₄ electrolytic gel enables a wider voltage window of 1.84 V. The designed device attains a remarkable specific capacitance of 249.43 F · g⁻¹ (areal 177.09 mF · cm⁻²) at 2 mV · s⁻¹. Noteworthy, a lightening LED panel along with a running small fan and 84.44% of electrochemical stability at 3000 cyclic voltametric cycles test; along with 95.49% capacitive retention at a mechanical bending angle of 170° marked as potential energy storage candidature for advanced flexible electronics.

With the rapid development of portable and wearable electronics, flexible fiber-shaped energy storage devices have emerged as important solutions due to their lightweight nature, long cycle life, and high safety. High-performance electrode materials are key to enhancing electrochemical performance. Carbon nanotubes (CNTs), with their 1D nanostructure, excellent mechanical properties, and ultra-high tensile strength, are considered ideal for constructing flexible energy storage electrodes, particularly in applications balancing flexibility and electrochemical performance. Recent years have seen significant progress in CNT-based flexible electrode research. To meet the demand for high-capacity flexible energy storage, this review focuses on CNT-based fiber-shaped devices, which exhibit high capacity and excellent mechanical flexibility. It summarizes recent advancements in energy storage, emphasizing fabrication and modification techniques for fiber electrodes and strategies for improved flexibility and stretchability. Furthermore, the structural design and performance of devices based on preparation methods are elaborated in detail, alongside a discussion of their wearable application potential. This review also addresses core challenges in the field and outlines future research directions for advancing fiber-shaped energy storage devices.

This review presents a comprehensive overview of key theories and methods for the fast activation of PEMFC, including air starving and hydrogen pumping, oxidative stripping, cyclic voltammetry, temperature and pressure control, and steaming or boiling the MEA. The principles, advantages, and limitations of these approaches are systematically analyzed. Furthermore, the fundamental mechanisms of electrochemistry and mass transport are discussed, with adsorption and reaction kinetics providing insights into interfacial processes and reaction optimization. The influence of water, gas, proton, and electron transport on fuel cell activation is also examined, highlighting strategies to enhance performance through transport optimization. A multiscale analysis integrating electrochemistry and proton transport is then conducted, spanning the nanoscale (triple-phase interfaces), mesoscale (fuel cell components), and macroscale (system control and component coordination).

High-nickel ternary materials are considered as promising cathode materials for lithium-ion batteries, primarily due to their high specific capacity and energy density. However, the crystal structure of high-nickel cathode materials undergoes significant changes during charge and discharge cycles. The accumulated stress leads to the formation and growth of microcracks along the inter-particle boundaries, ultimately compromising particle integrity. Repeated volume contractions and expansions eventually cause further pulverization of the material. In this study, Al³⁺ ion doping was employed to stabilize the layered structure of the high-nickel ternary materials. Al³⁺-doped LiNi_0.8Co_0.1Mn_0.1O₂ was synthesized by a one-step solid-state sintering method. The characterization confirmed that Al³⁺ ions were successfully doped into the transition metal layers of the cathode material and formed stronger Al─O covalent bonds, which enhanced the stability of the bulk phase structure, suppressed phase transition, and microcracks. The cathode material doped with 1.5 mol.% Al³⁺ exhibited excellent cycling stability, with a capacity retention rate increased by 15.01% after 600 cycles compared to the pristine specimen. In addition, Al³⁺ doping reduces cation mixing and optimizes ion transport kinetics, the discharge capacity reached 145.5 mAh·g⁻¹ at 10 C rate. Therefore, achieving Al³⁺ ion doping through co-lithium sintering provides an effective strategy for improving the performance of high-nickel cathode materials in lithium-ion batteries.

Rechargeable batteries with high power density, better safety, wide operating temperature, and extended lifespans are needed for renewable energy. These batteries must also be produced cheaply using plentiful resources. Fluorine, the most electronegative and reactive halogen, having natural abundance and strong bonds (i.e., C─F and Li─F bonds, making fluorinated constituents inexpensive, nonflammable, and intrinsically stable. Using fluorine chemistry to optimize battery engineering is thought to be a crucial strategy to meet these requirements. Excellent kinetic reactivity allows fluorine-containing electrolyte additions to preferentially create robust SEI and homogeneous electrode-electrolyte interface films, which can significantly enhance the battery electrochemical performance. To improve safety performance, fluorine-containing electrolyte additions might be utilized as flame inhibitors. The incorporation of fluorinated salts, dissolution agents, or functional additives brought significant improvements in batteries based on conventional organic carbonate-based electrolytes. It has been shown that the safety, thermal resilience, and reaction kinetics of rechargeable batteries are greatly impacted by fluorine-containing materials and the interphases of electrode-electrolyte. The investigation of fluorinated salts, polymer matrices, and other fluorinated battery components for lithium batteries (LBs), as well as the recent development in electrochemical performance, interface engineering, and future outlook, are the major subjects covered in this paper.

This review discusses electrochemical energy systems with a focus on proton exchange membrane fuel cells (PEMFCs), highlighting the key role of proton exchange membranes (PEMs) in fuel cell performance. Among various PEM materials, Perfluorosulfonic acid (PFSA) ionomers are widely used due to their excellent chemical and proton-conducting properties. The present review places special emphasis on short-side-chain (SSC) PFSA ionomers, which have gained attention over conventional long-side-chain (LSC) types like Nafion. SSC-PFSAs offer improved thermal stability, higher crystallinity, and better proton conductivity, making them more suitable for demanding fuel cell conditions, especially under low humidity. The review also discusses important membrane properties such as water uptake, proton transport, and durability challenges. To address performance limitations, the use of composite membranes with suitable reinforcements and functional fillers is explored as a strategy to enhance conductivity, mechanical strength, and long-term stability. Overall, this review sets the foundation for understanding the significance of SSC-PFSA membranes and their potential in next-generation fuel cells.

Atmospheric water harvesting (AWH) techniques are evolving technologies that extract water from ambient air. These techniques have been utilized because of their potential in various engineering fields, especially building envelopes. Despite their potential, integrating AWHs into building envelopes remains a novel area that requires further investigation for practical applications within buildings. The lack of visibility and precise classification of AWH applications within building envelopes motivated a review of articles published since 2010, focusing on integrated AWH techniques within building envelopes and discovering their prevalent applications used in buildings to provide a clear categorization of these applications for future envelope development. For this purpose, this research conducted a systematic literature review, employing the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) protocol, of the main AWH technologies implemented in building envelopes. It evaluates the practical applications of AWHs by identifying the reasons for incorporating such techniques within the envelopes. The findings indicate existing technologies have primarily been employed to provide dehumidification for various purposes, enhance the building's energy performance by regulating relative humidity, and use harvested water for surface evaporation. Additionally, AWH applications through envelopes have been expanded to serve as sustainable water supplies as a key area of focus.

Graphite is considered as the benchmark anode for lithium-ion batteries (LIB) due to its good performance metrics. However, graphite has limitations for high-power conditions due to safety concerns. Hard carbon (HC) represents a structurally disordered carbonaceous material that has a better rate capability and better temperature stability than graphite. This study introduces a sustainable composite anode material of regenerated spent graphite (SG) and hard carbon, distinguishing it from previously reported materials. Herein, we have systematically studied the performance of HC, the regenerated SG, and its composites HC:SG-3:1, HC:SG-1:1 and HC:SG-1:3. The specific capacity of HC was 198 mAh/g compared to 301 mAh/g of SG at a rate of C/2; when these electrodes were tested at a rate of 5C, HC delivered 113 mAh/g while the SG delivered only 40 mAh/g. Also, cycling of HC, HC:SG-3:1, HC:SG-1:1, and SG delivered a capacity of 125, 109, 104, and 76 mAh/g respectively, at the end of the 500^th cycle at a 5C rate. The full-cell performance of the HC:SG composite showed satisfactory performance with an energy density of 260 Wh/kg_a. Further, ex situ surface chemical analysis was carried out in pristine and cycled electrodes to understand the chemical changes upon cycling.