The global market for lithium-ion batteries continues to grow, and the number of spent lithium-ion batteries is increasing along with the wave of battery retirements. As an important secondary resource, the recycling of spent lithium-ion batteries is of great significance in alleviating the consumption of battery raw materials and avoiding environmental pollution. In the recycling process, the separation of the cathode active material containing valuable metals from the collector is an important prerequisite for reducing the difficulty and complexity of the subsequent metal extraction process. Unlike most reviews that focus on metal extraction, this paper discusses and analyses the separation techniques of cathode active material. Starting from the bonding mechanism between cathode active material and collector, the separation techniques (mechanical, dissolution, pyrolysis and other novel methods) are discussed in detail. The dissociation mechanisms involved in the separation technology are discussed in focus, and an outlook on the subsequent separation technology for cathode materials is presented. This paper helps to provide a systematic understanding for researchers and workers interested in the separation of electrode materials from spent lithium-ion batteries, and has important reference value.

Alginate, known for its unique properties such as biocompatibility, biodegradability, and gel forming capability, has emerged as a corrosion-resistant material in aqueous environments for sustainable and environmentally friendly solutions. Further, alginate-based composites possess self-healing features through their distinctive molecular structure, encapsulating unprotected metal surfaces and preventing additional corrosion. As a result, alginate-based coatings on metals provide extended corrosion protection while requiring less frequent maintenance, which is highly attractive for long-term use in hostile settings. In this review, we comprehensively explore the diverse applications of alginate-based coatings, with a focus on their roles in corrosion inhibition, antifouling, and biocidal activities. After a brief introduction to the fundamental principles of corrosion-resistance behaviors, we will examine the interfacial and surface properties that make alginate-based coatings effective for these protective functions. This includes an analysis of their molecular structure, amphiphilic nature, and specific attributes that contribute to their effectiveness in various industrial applications such as ship hulls, undersea structures, and maritime equipment. We also review the current state of research, evaluation methods, and comparative analyses with traditional coatings in each segment. Last, the review highlights the advantages of alginate-based coatings, along with the challenges and future perspectives.

Water-induced Electric Generators (WEGs) exhibit tremendous promise as sustainable energy sources harvesting electricity through the interaction between materials and water utilizing the hydrovoltaic effect, an innovative green energy harvesting method. However, existing WEG devices predominantly rely on inorganic materials with limited research on naturally available, bio-based materials for hydrovoltaic energy harvesting. This study introduces a novel nutshell-based hydrovoltaic WEG for the first time. This low-cost, organic, and efficient renewable energy source can generate a voltage above 600 mV with a power density exceeding 5.96 µW·cm−2 utilizing streaming and evaporation potential methodologies, which can be sustained for more than a week. Notably, after further chemical treatments and combining the physical and chemical phenomena, output voltage and maximum current density reach a record high of 1.21 V and 347.2 µA·cm−2respectively, which outperforms most inorganic and organic materials based WEGs. By connecting two units in series and parallel this eco-friendly WEG can power an LCD calculator without the assistance of any rectifier. We believe that this novel nutshell-based WEG provides a significant advancement in WEG technology by offering a sustainable solution for powering electronic devices utilizing agricultural waste.

Photocatalytic processes of carbon dioxide (CO2) conversion and molecular hydrogen (H2) production could potentially address two major global challenges: greenhouse gas (GHG) mitigation and clean energy generation, respectively. During photocatalysis, the energy harvested via the light absorption in photosensitizers drives the important chemical reactions using the photogenerated charges to convert water into H2 or CO2 into value-added products. Recent decades have witnessed the widespread popularity of photocatalytic technology owing to its sustainable, renewable, and greener pathway to produce fuels and chemicals. Given this, a wide range of materials have been explored for photocatalytic applications. Among the developed materials, Ni-based photocatalysts have received considerable attention due to their distinct properties including low cost, stability, abundance, and high activity. This review addresses recent developments concerning nickel (Ni)-based photocatalysts used in photocatalytic CO2 conversion and H2 production. The use of Ni-materials plays a crucial role in enhancing photocatalytic activity through improved light-absorption, charge-separation, along with suppressed charge recombination to enhance the efficiency of hydrogen evolution and CO2 conversion. The performance of nickel-based photocatalysts during CO2 reduction and water splitting reactions is summarized, which provide a comprehensive overview of Ni-based photocatalyst efficiency and selectivity. Finally, challenges and future prospects are examined in detail for further optimization of Ni-based photocatalysts. This review also provides an update on the studies that have been conducted on Ni-based materials for H2 generation and CO2 reduction.

Solid oxide fuel cells (SOFCs) are widely presented as a sustainable solution to future energy challenges. Nevertheless, SOFCs presently rely on significant use of several critical raw materials to enable optimised reaction kinetics at the device electrodes. This challenge can be addressed through the use of thin-film electrode materials, however this is typically accompanied by complex device fabrication procedures as well as poor mechanical and chemical stability. In this work, we conduct a systematic study of a range of promising thin-film electrode materials based on vertically aligned nanocomposite (VAN) thin films. We demonstrate low area specific resistance (ASR) values of 0.44 cm2 at 650° C can be achieved using (La0.60Sr0.40)0.95Co0.20Fe0.80O3 - (Sm2O3)0.20(CeO2)0.80 (LSCF-SDC) thin films, which are also characterised by a low degradation rate, approximately half that of planar LSCF thin films. We then integrate these LSCF-SDC VAN films directly with commercial anode supported half cells through a single step deposition process. The resulting cells exhibit peak power density of 0.47 W/cm2 at 750° C, competitive with 0.64 W/cm2 achieved for the same cells operating with a bulk LSCF cathode despite 99.5% reduction in cathode critical raw material use. Therefore, the present work marks a valuable step towards the sustainable proliferation of SOFC technology.

This study explores the synthesis of high-entropy alloy (HEA) nanoparticles with core-shell structures using hydrogen reduction-assisted ultrasonic spray pyrolysis (USP). The focus is on synthesizing nanoparticles with transition metal based CoCuFeNi and CoCuFeNiZn HEA shells over iron oxide cores. The USP method enabled precise control over particle composition and morphology, resulting in spherical nanoparticles with complex core-shell configurations. The first synthesized particles with a CoCuFeNi shell over an Fe3O4 core (Fe3O4@CoCuFeNi) exhibited an average grain size of 144.9 nm. Subsequent synthesis involving the addition of Zn resulted in a CoCuFeNiZn shell over an FeO core (FeO@CoCuFeNiZn). The addition of Zn not only contributed to the shell composition but also modified the type of iron oxide core from Fe3O4 to FeO, increasing the grain size of the nanospheres to an average diameter of 224.4 nm. Electrocatalytic testing showed that Fe3O4@CoCuFeNi exhibited outstanding oxygen evolution reaction (OER) activity in 1 M KOH alkaline media. These nanospheres required overpotentials of 306 mV at 10 mA cm², with a Tafel slope of 61.5 mV dec⁻¹. Meanwhile, FeO@CoCuFeNiZn demonstrated a higher overpotential of 378 mV at 10 mA cm² and a Tafel slope of 65.4 mV dec⁻¹, underlining the influence of zinc addition on catalytic activity. Compared to some other HEAs and commercial IrO2 electrocatalysts, both core-shell nanosphere variants show improved charge transfer and reaction kinetics, underscoring their potential as cost-effective and highly efficient electrocatalysts for sustainable water electrolysis.

The limited space in urban areas often presents a challenge for harnessing renewable energy, particularly solar energy. However, this obstacle can be overcome by using building facades to generate energy. The global energy consumption significantly affected by building, contributing significantly demand and greenhouse gases. These buildings require energy (electrical & thermal) for various processes. Photovoltaic/thermal (PV/T) systems can offer a solution by producing both electrical and thermal energies, simultaneously. The circulating working fluid within the system will reduce the surface temperatures of PV panels and subsequently improving the electrical efficiency. Integrating PV/T systems into building facades, known as building-integrated PV/T (BIPV/T) systems, enables efficient production of energy, enhancing the overall energy consumption of buildings. The aim of the current review is to provide an outline of BIPV/T systems; explaining how they work, their classification, the benefits of their utilization in buildings, and techniques for energy enhancement in buildings. The primary objective of this review is to offer researchers up-to-date information on BIPV/T systems available in the literature. It includes recent published technological advancements in BIPV/T systems, focuses on the cited works and their key areas of interest, and provide readers with a comprehensive and systematic overview of the topic rather than an exhaustive analysis of BIPV/T systems.

Triboelectric nanogenerators (TENGs) are emerging as new technologies to harvest electrical power from mechanical energy. With the distinctive working mechanism of triboelectric nanogenerators, they attract particular interest in healthcare monitoring, wearable electronics, and deformable energy harvesting, which raise the requirement for highly conformable devices with substantial energy outputs. Here, a simple, low-cost strategy for fabricating stretchable triboelectric nanogenerators with ultra-high electrical output is developed. The TENG is prepared using PTFE micron particles (PP-TENG), contributing a different electrostatic induction process compared to TENG based on dielectric films, which was associated with the dynamics of particle motions in PP-TENG. The generator achieved an impressive voltage output at 1000 V with current of 25 µA over a contact area of 40×20 mm2. Additionally, the TENG exhibits excellent durability with a stretching strain of 500%, and the electrical output performance does not show any significant degradation even after 3000 cycles at a strain of 400%. The unique design of the device provides high conformability and can be used as a self-powered sensor for human motion detections.

A touch sensor is an essential component in meeting the growing demand for human-machine interfaces. These sensors have been developed in wearable, attachable, and even implantable forms to acquire a wide range of information from humans. To be applied to the human body, sensors are required to be biocompatible and not restrict the natural movement of the body. Ionic materials are a promising candidate for soft touch sensors due to their outstanding properties, which include high stretchability, transparency, ionic conductivity, and biocompatibility. Here, this review discusses the unique features of soft ionic touch position sensors, focusing on the ionic material and its key role in the sensor. The touch sensing mechanisms include piezocapacitive, piezoresistive, surface capacitive, piezoelectric, and triboelectric and triboresistive sensing. This review analyzes the implementation hurdles and future research directions of the soft ionic touch sensors for the transformative potential.

A heteronuclear dual transition metal atom catalyst is a promising strategy to solve and relieve the increasing energy and environment crisis. However, the role of each atom still does not efficiently differentiate due to the high activity but low detectivity of each transition metal in the synergistic catalytic process when considering the influence of heteronuclear induced atomic difference for each transition metal atom, thus seriously hindering intrinsic mechanism finding. Herein, we proposed coordinate environment vary induced heterogenization of homonuclear dual transition metal, which inherits the advantage of heteronuclear transition metal atom catalyst but also controls the variable of the two atoms to explore the underlying mechanism. Based on this proposal, employing density functional theory study and machine learning, 23 kinds of homonuclear transition metals are doping in four asymmetric C3N for heterogenization to evaluate the underlying catalytic mechanism. Our results demonstrate that five catalysts exhibit excellent catalytic performance with a low limiting potential of -0.28 to -0.48 V. In the meantime, a new mechanism, ‘capture-charge distribution-recapture-charge redistribution’, is developed for both side-on and end-on configuration. More importantly, the pronate site of the first hydrogenation is identified based on this mechanism. Our work not only initially makes a deep understanding of the transition dual metal-based heteronuclear catalyst indirectly but also broadens the development of complicated homonuclear dual atom catalysts in the future.

The development of cost-effective, highly efficient, and durable electrocatalysts has been a paramount pursuit for advancing the hydrogen evolution reaction (HER). Herein, a simplified synthesis protocol was designed to achieve a self-standing electrode, composed of activated carbon paper embedded with Ru single-atom catalysts and Ru nanoclusters (ACP/RuSAC+C) via acid activation, immersion, and high-temperature pyrolysis. Ab initio molecular dynamics (AIMD) calculations are employed to gain a more profound understanding of the impact of acid activation on carbon paper. Furthermore, the coexistence states of the Ru atoms are confirmed via aberration-corrected scanning transmission electron microscopy (AC-STEM), X-ray photoelectron spectroscopy (XPS), and X-ray absorption spectroscopy (XAS). Experimental measurements and theoretical calculations reveal that introducing a Ru single atom site adjacent to the Ru nanoclusters induces a synergistic effect, tuning the electronic structure and thereby significantly enhancing their catalytic performance. Notably, the ACP/RuSAC+C exhibits a remarkable turnover frequency (TOF) of 18 s-1 and an exceptional mass activity (MA) of 2.2 A mg-1, surpassing the performance of conventional Pt electrodes. The self-standing electrode, featuring harmoniously coexisting Ru states, stands out as a prospective choice for advancing HER catalysts, enhancing energy efficiency, productivity, and selectivity.

Direct synthesis of layer-tunable and transfer-free graphene on technologically important substrates is highly valued for various electronics and device applications. Here, we report a novel synthesis approach combining ion implantation for a precise graphene layer control and dual-metal smart Janus substrate for a diffusion-limiting graphene formation, to directly synthesize layer-tunable graphene on arbitrary substrates without the post-synthesis layer transfer process. C ion implantation was performed on Cu-Ni film deposited on a variety of device-relevant substrates. Upon thermal annealing to promote Cu-Ni alloying, the pre-implanted C-atoms in the Ni layer are pushed towards the Ni/substrate interface by the top Cu layer due to the poor C-solubility in Cu. As a result, the expelled C-atoms precipitate into graphene structure at the interface facilitated by the Cu-like alloy catalysis. After removing the alloyed Cu-like surface layer, the layer-tunable graphene on the desired substrate is directly realized. ReaxFF was performed to elucidate the graphene formation mechanisms in this novel synthesis approach. Three ordinary devices using as-synthesized graphene were fabricated on Si, SiO2, and glass substrates to demonstrate the graphene quality of our layer-tunable and transfer-free synthesis approach and the excellent performance characteristics of these low-cost manufacturing devices: field-effect transistors, heating devices, and near-infrared photodetectors.

Aqueous rechargeable zinc-ion batteries (ZIBs) have garnered considerable attention due to their safety, cost-effectiveness, and eco-friendliness. There is a growing interest in finding suitable cathode materials for ZIBs. Layered vanadium oxide has emerged as a promising option due to its ability to store zinc ions with high capacity. However, the advancement of high-performance ZIBs encounters obstacles such as sluggish diffusion of zinc ions resulting from the high energy barrier between V2O5 layers, degradation of electrode structure over time and consequently lower capacity than the theoretical value. In this study, we investigated the pre-doping of different cations (including , , and ) into V2O5 to enhance the overall charge storage performance. Our findings indicate that the presence of V4+ enhances the charge storage performance, while the introduction of into V2O5 (NH4-V2O5) not only increases the interlayer distance (d(001) = 15.99 Å), but also significantly increases the V4+/V5+ redox couple (atomic concentration ratio increased from 0.14 to 1.08), resulting in the highest electrochemical performance. The NH4-V2O5 cathode exhibited a high specific capacity (310.8 mAh g-1 at 100 mA g-1), improved cycling stability, and a significantly reduced charge transfer resistance compared to pristine V2O5.

Thick and highly conductive PEDOT:PSS films with ideal morphologies, are desirable as electrodes for supercapacitors. However, building uniform micro-morphology without templates or composite strategies is a formidable challenge, primarily caused by the inherent softness of dominant PSS. Herein, we successfully realized morphology control, transitioning from a layer-by-layer architecture to a porous structure in thick PEDOT:PSS films by employing solvothermal method with ethylene glycol (EG) as the solvent. The combined effect of high pressure and temperature effectively drove EG to construct the microstructure of thick PEDOT:PSS films by detaching insulating PSS chains and enhancing PEDOT crystallinity, and simultaneously facilitated the formation of a porous network through EG molecular tailoring. The achieved porous thick PEDOT:PSS films delivered a high conductivity of 1644 S cm-1 and a champion specific capacitance of 270 F cm-3, significantly surpassing previously reports. The flexible all-solid-state supercapacitor assembled based on the films displayed an excellent specific capacitance of 97.8 F cm-3 and an energy density of 8.7 mWh cm-3, representing the highest values for pure PEDOT:PSS-based supercapacitors. This research provides an effective novel method for conducting polymer morphology control and promotes the applications of PEDOT:PSS in the field of energy storage.

In this work, we reported a series of monolithic 3D-printed Ni-Mo alloy electrodes for highly efficient water splitting at high current density (1500 mA cm-2) with excellent stability, which provides a solution to scale up Ni-Mo catalysts for HER to industry use. All possible Ni-Mo metal/alloy phases were achieved by tuning the atomic composition and heat treatment procedure, and they were investigated through both experiment and simulation, and the optimal NiMo phase shows the best performance. Density functional theory (DFT) calculations elucidate that the NiMo phase has the lowest H2O dissociation energy, which further explains the exceptional performance of NiMo. In addition, the microporosity was modulated via controlled thermal treatment, indicating that the 1100 C sintered sample has the best catalytic performance，which is attributed to the high electrochemical surface area (ECSA). Finally, the 4 different macrostructures were achieved by 3D printing, and they further improved the catalytic performance. The gyroid structure exhibits the best catalytic performance of driving 500 mA cm-2 at a low overpotential of 228 mV and 1500 mA cm-2 at 325 mV as it maximizes the efficient bubble removal from the electrode surface, which offers the great potential for high current density water splitting.

Electrocatalytic reduction of CO2 into high energy-density fuels and value-added chemicals under mild conditions can promote the sustainable cycle of carbon and decrease current energy and environmental problems. Constructing electrocatalyst with high activity, selectivity, stability and low cost is really matter to realize industrial application of electrocatalytic CO2 reduction (ECR). Metal-nitrogen-carbon (M-N-C) electrocatalysts, especially Ni-N-C, display excellent performance, such as nearly 100% CO selectivity, high current density, outstanding tolerance, etc., which is considered to possess broad application prospects. Based on the current research status, starting from the mechanism of ECR and the existence form of Ni active species, the latest research progress of Ni-N-C electrocatalysts in CO2 electroreduction is systematically summarized. An overview is emphatically interpreted on the regulatory strategies for activity optimization over Ni-N-C, including N coordination modulation, vacancy defects construction, morphology design, surface modification, heteroatom activation, bimetallic cooperation. Finally, some urgent problems and future prospects on designing Ni-N-C catalyst for ECR are discussed. This review aims to provide the guidance for the design and development of Ni-N-C catalyst with practical application.

Aqueous zinc-ion batteries (AZIBs) are regarded as the promising candidates for large-scale energy storage systems owing to low cost and high safety; however, their applications are restricted by their poor low-temperature performance. Herein, a low-temperature electrolyte for low-temperature AZIBs is designed by introducing low-polarity diglyme (DGM) into an aqueous solution of Zn(ClO4)2. The DGM disrupts the hydrogen-bonding network of water and lowers the freezing point of the electrolyte to -105 °C. The designed electrolyte achieves ionic conductivity up to 16.18 mS cm-1 at -45 °C. The DGM and ClO4- reconfigure the solvated structure of Zn2+, which is more favorable for the desolvation of Zn2+ at low temperatures. In addition, the DGM effectively suppresses the dendrites, hydrogen evolution reaction, and by-products of the zinc anode, improving the cycle stability of the battery. At -20 °C, a Zn||Zn symmetrical cell is cycled for 4,500 h at 1 mA cm-2 and 1 mA h cm-2, and a Zn|| polyaniline (PANI) battery achieves an ultra-long cycle life of 10,000 times. This study sheds light on the future design of electrolytes with high ionic conductivity and easy desolvation at low temperatures for rechargeable batteries.

This study explores enhancing salinity gradient power using 2D materials due to their surface-governed charge. However, achieving high-performing membranes with superior ion selectivity and low ionic resistances remains challenging. To address this issue, Al(OH)4- anions were incorporated into graphene oxide membranes to increase their spontaneous negative surface charge. The anions were successfully formed and encapsulated through a reaction with the alumina support under alkaline conditions during the membrane formation. The membranes’ physicochemical properties were analyzed by means of selected characterization techniques. The incorporation of Al(OH)4- anions significantly improved permselectivity and ionic resistance, reaching approximately 95% and 2 Ω cm2, respectively. A modeling of the system was carried out to further understand the anchoring of these ions within the membrane matrix and their role in boosting the charge of the membrane and, therefore, their electrochemical properties. The study delved into the utilization of GO membranes as monovalent-selective membranes, an approach to boost reverse electrodialysis power densities. The membranes demonstrated impressive selectivity, overcoming 70 folds for divalent cations over K+.