A recycling process for recovering cobalt from lithium-ion battery cathode production scraps is investigated using green solvents. The method combines electrode delamination with triethyl phosphate (TEP), dissolution of the recovered active material in a deep eutectic solvent (DES) composed of choline chloride and oxalic acid (1:1 molar ratio), and selective cobalt precipitation via controlled pH adjustment with KOH. The recovered black mass was characterized by Powder X-ray diffraction PXRD and Thermogravimetric analysis (TGA), confirming structural integrity of LiCoO2 after TEP treatment and a purity of ~98.25%. Following DES leaching and precipitation at pH 12, a highly crystalline mixed cobalt oxide/hydroxide phase (CoO2/Co(OH)2) was obtained with a purity of 99.12%. Microwave Plasma Atomic Emission Spectroscopy (MP-AES) analysis verified effective cobalt–lithium separation, with cobalt exclusively recovered in the solid phase. A cobalt recovery efficiency of 57% was achieved at lab scale, with losses primarily attributed to material handling at low Technology Readiness Level (TRL) rather than process inefficiency. A cradle-to-gate Life Cycle Assessment (LCA) was conducted using primary experimental inventory data. Environmental hotspot analysis identified DES preparation and the leaching step as the dominant contributors across most impact categories, driven respectively by solvent production (oxalic acid and choline chloride) and electricity consumption. Sensitivity and uncertainty analyses confirmed model robustness and highlighted renewable energy transition and solvent optimization as key levers for future improvement. This early-stage LCA provides a quantitative environmental baseline to support eco-design and scale-up of DES-based cobalt recovery from lithium cobalt oxide (LCO) cathode waste.

Developing a Hybrid Energy Storage System (HESS) involves integrating technologies with complementary attributes. Coupling Redox Flow Batteries (RFBs) with Supercapacitors (SCs) emerges as one of the most promising options. For the first time at our knowledge, here we report about a study on the passive HESS VRFB-SC configuration that was investigated through experimental tests, modelling, life cycle and economic assessments. Indeed, we present a laboratory-sized HESS comprising a Vanadium Redox Flow Cell (VRFC) and a SC, directly connected in parallel without any power converter. Initially, individual tests were conducted on the standalone VRFB and SC using short discharge protocols (5 s). Subsequently, the two systems were interconnected in parallel and subjected to the same discharge protocol. An equivalent electrical model, resembling a parallel R-C circuit, was developed to elucidate the discharge mechanism of the direct parallel system. The tests revealed that the SC mitigates the VRFB's ohmic drop due to the transient behaviour of the R-C circuit. Furthermore, the hybrid system demonstrated enhanced energy delivery at higher currents compared to the standalone VRFB, a phenomenon elucidated by our proposed model. Additionally, the model facilitates the sizing of the SC relative to VRFB performance. In addition to technical findings, this article provides a comprehensive economic analysis and life cycle assessment (LCA) of the proposed system. These assessments highlight the potential cost-effectiveness and reduced global warming potential of the passively connected VRFB-SC HESS, underscoring its viability as a sustainable energy storage solution.

Accurate determination of the lithium-ion diffusion coefficient (D-Li(+)) is essential for understanding mass-transport limitations in graphite anodes and for improving the performance of lithium-ion batteries. However, the calculation of D-Li(+) obtained from pulsed electrochemical techniques critically depends on the assumed active surface area, for which no standardized definition currently exists. In this work, we quantitatively assess how different surface area approximations-geometrical area, scanning electron microscopy-derived area, and Brunauer-Emmett-Teller surface area-affect the diffusion coefficient extracted from galvanostatic intermittent titration technique and intermittent current interruption analyses. Both methods were applied to a commercial graphite electrode using an identical dataset, enabling a direct and unbiased comparison of diffusion trends. We show that the choice of surface area leads to variations in D-Li(+) spanning several orders of magnitude, due to the squared dependence of the area term in the diffusion equation. Overall, our results demonstrate that careful and consistent surface area selection is crucial for reliable diffusion measurements and for ensuring comparability across studies.

The rising demand for lithium‐ion batteries (LIBs) highlights the importance of developing electrode fabrication methods that ensure high performance, cost efficiency, and environmental sustainability. Here, wet (slurry‐based) and dry (solvent‐free) electrode fabrication methods are compared with a focus on both anodes and cathodes. Despite its integration within an established industrial system, the wet method exhibits significant limitations stemming from the use of volatile solvents such as N‐methyl‐2‐pyrrolidone (NMP), the high energy demand of the drying stage, and the complexity of scaling up thick electrode manufacturing. On the other hand, dry electrode fabrication eliminates the need for solvents, reduces energy use, simplifies production workflows, and improves mechanical integrity. The latter helps in the development of high‐loading electrodes for next‐generation high‐energy density storage systems. However, dry processing introduces new technical challenges that must first be addressed, including binder activation, uniform material dispersion, the need for specialized hardware, and the development of customized equipment. By focusing on the underlying mechanisms, advantages, and practical limitations, this review aims to support the development of optimized electrode fabrication strategies that facilitate the widespread adoption of sustainable battery technologies.

Next-generation electronic devices, including embedded microsystems and wearable technologies, require the development of safe, and low-cost energy storage systems to meet the 21st-century society demands. In this context, several ecological binders have been developed and amended in order to achieve high-performance carbon-based supercapacitors. This work demonstrates a solid state-based supercapacitor using Pullulan (Pu)/Polyvinyl Alcohol (PVA) composite as an eco-friendly binder for the first time, for carbon-based electrodes development. Furthermore, PVA/KOH/Glycerol (GCy) blends are used as conductive electrolytes towards safe and light weight devices manufacturing. The electrodes are fabricated through simple and low-cost hand-painting (paint brush) on Nickel foam substrates. The device shows an interesting areal capacitance of 176 mF cm(-2) at 10 mV s(-1), energy and power densities of 25 & micro;Wh cm(-2) and 3.2 mW cm(-2) respectively, at 0.5 A g(-1). More importantly, the device demonstrates robust mechanical strength with excellent reversibility across various bending angles (0 degrees, 90 degrees, 180 degrees), with a capacitance retention of 90% after 10 000 charging/discharging cycles while maintaining an important coulombic efficiency (>95%). The outcomes of this work are quite promising compared to many reported studies, opening wide potential application in the field of handheld electronics.

Lithium‐ion batteries (LIBs) represent the dominant energy storage technology, and as their demand continues to rise, the efficient recycling and recovery of critical elements from their cathodes become increasingly important. Direct recovery of active electrode materials from spent LIBs or electrode manufacturing scraps offers an effective strategy to obtain secondary materials that are ready for reuse in electrode reconstruction and reintegration into the LIB supply chain. In direct recycling processes, active materials must first be detached from their current collectors. This separation is typically achieved either through thermal decomposition of the binder, that is typically a per‐ and polyfluoroalkyl substance (PFAS) like polyvinylidene difluoride (PVDF), or by dissolving the binder in dipolar aprotic solvents, which are unsuitable for large‐scale applications due to their toxicity. This study investigates the direct recovery of both active materials and the PVDF polymeric binder from real LiCoO2 cathode production scraps. Separation from aluminum and current collector was accomplished using the green solvent triethyl phosphate, while process parameters such as dissolution time, temperature, and solid‐to‐liquid ratio were systematically optimized. The recovered active material and binder were subsequently characterized using multiple analytical techniques and reused for electrode remanufacturing, confirming the effectiveness of this environmentally friendly and readily scalable process.

Graphite is commonly used as anode material in Li-Ion Batteries (LIBs). However, its applicability in next-generation LIBs is limited by its low specific capacity. Mixing graphite with silicon is relevant to increase the specific capacity while maintaining good cycling stability. Previous studies considered the impact of the silicon content on the electrochemical performance of silicon-graphite anodes, but not specifically on the evolution of electronic transport during charging/discharging. This present study focuses on the use of the Ion-Gated Transistor (IGT) configuration to evaluate how electronic transport (e.g. charge carrier density and mobility) evolves in pure graphite and silicon-graphite composite anodes during charge/discharge processes, as a function of the Si content. We employed graphite and silicon-graphite composites with 5, 15, 20 and 80 wt% of Si as transistor channel materials and 1-Ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([EMIM][TFSI]) containing 0.5 M of lithium bis(trifluoromethane)sulfonimide (LiTFSI) as the ion gating medium. Our results show that the electronic current increases with the degree of lithiation, for all materials. Moreover, increasing the silicon content in the SiG composite affects the charge carrier density. This study contributes to the design and optimization of silicon-graphite anodes for next-generation LIBs.

Lithium-ion batteries (LIBs) are integral to modern technology, powering everything from portable electronics to electric vehicles. Advancing their performance depends on a detailed understanding of electronic and ionic transport in cathode materials. In this study, we investigated the transport properties of NMC811 (LiNi 0.85 Mn 0.05 Co 0.1 O 2 ), a high-capacity cathode material with great potential for next-generation LIBs. We employed an ion-gated transistor (IGT) configuration, using NMC811 as the channel material, interfaced with the ionic liquid [EMIM][TFSI] and tested both with and without LiTFSI salt. The three-electrode IGT setup enabled simultaneous monitoring of the cathode’s redox activity and electronic conductivity under in operando conditions. Complementary electrochemical impedance spectroscopy (EIS) provided insights into charge transfer kinetics and electronic conductivity. The effects of gate bias on electronic conductivity were studied, revealing their influence on lithiation/delithiation dynamics. Additionally, X-ray diffraction (XRD) characterized structural changes in NMC811 before and after cycling. By combining electrochemical and structural analyses, we explored the interplay between ionic and electronic conductivity, providing critical insights into the state of charge in LIBs. These findings offer a foundation for optimizing cathode materials and advancing LIB technology.

Background: Sediment microbial fuel cells (SMFCs) are efficient platforms for electricity generation and organic/ inorganic material removal from sediment. The use of multi-electrode systems is vital for enhancing power and current generation while ensuring stability under bioturbation processes. Methods: This study investigates the influence of anode and cathode configurations on the performance of various SMFCs with constant total electrode area and identical sediment. We specifically analyzed the impact of one, two, four, and eight graphite electrodes as anodes and cathodes in four SMFC setups. Cyclic voltammetry (CV) and impedance tests were conducted to assess performance. Significant findings: Results show that the four-anode configuration exhibited increased current generation, while having four cathodes improved performance according to impedance tests. However, using eight cathodes led to decreased power and increased ohmic resistance due to cathodic restriction. SMFC A, with eight anodes and four cathodes, achieved a peak power output of 394 mu W, while SMFC B, with four anodes and cathodes, reached a maximum current of 1600 mu A. These values represent significant enhancements compared to single-anode setups with the same electrode surface area. This study highlights the potential for improving SMFC performance through strategic multi-electrode configurations.

Li-ion battery (LIB) electrode materials feature mixed electronic-ionic transport. Their electronic conductivity is expected to depend on the degree of de-lithiation/lithiation, but it is challenging to evaluate such dependence as disentangled from ionic conductivity. Herein, we use the Ion-Gated Transistor (IGT) configuration to study the dependence of the electronic conductivity of lithium cobalt oxide (LiCoO2 or LCO)-based composite cathode material. LCO-based composite is employed as transistor channel interfaced with the ionic liquids: 1-Ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([EMIM][TFSI]) and 1-Butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide ([PYR14][TFSI]), both without and with lithium bis(trifluoromethane)sulfonimide salt (LiTFSI). The gate-source bias controls the degree of lithiation/de-lithiation in the LCO composite-based IGT. We observed an increase in the drain-source transistor current upon the application of a gate-source bias, i.e., upon Li+ de-intercalation from the LCO composite cathode material. Our results pave the way for the in operando evaluation of the state-of-charge (SOC) of LIB electrode materials, crucial for their efficient and sustainable use.

Li-ion battery (LIB) electrode materials feature mixed electronic-ionic transport. Their electronic conductivity is expected to depend on the degree of de-lithiation/lithiation, but it is challenging to evaluate such dependence as disentangled from ionic conductivity. Herein, we use the Ion-Gated Transistor (IGT) configuration to study the dependence of the electronic conductivity of lithium cobalt oxide (LiCoO2 or LCO)-based composite cathode material. LCO-based composite is employed as transistor channel interfaced with the ionic liquids: 1-Ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([EMIM][TFSI]) and 1-Butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide ([PYR14][TFSI]), both without and with lithium bis(trifluoromethane)sulfonimide salt (LiTFSI). The gate-source bias controls the degree of lithiation/de-lithiation in the LCO composite-based IGT. We observed an increase in the drain-source transistor current upon the application of a gate-source bias, i.e., upon Li+ de-intercalation from the LCO composite cathode material. Our results pave the way for the in operando evaluation of the state-of-charge (SOC) of LIB electrode materials, crucial for their efficient and sustainable use.

This study deals with the preparation and solid-state characterization, as well as structural and phase transition features of supramolecular complexes composed of sodium hydrogen sulfate (NaHSO4) and two crown ether ligands, namely, 15-crown-5 and benzo-15-crown-5. Single crystals for each compound were grown, and their structures were elucidated via single-crystal X-ray diffraction (XRD) analysis, which highlighted the following compositions: [15-crown-5·Na]-HSO4 (1) and [benzo-15-crown-5·Na]-HSO4 (2). Microcalorimetric analyses, hot-stage microscopy, and variable-temperature powder X-ray diffraction were employed to analyze thermal stability and phase transition behaviors. Variable-temperature 1H T 1 solid-state NMR measurements were also used to monitor proton dynamics and to determine activation energies associated with motion across phase transitions. Formation of supramolecular complexes is crucial for inducing solid-solid transitions, leading to superprotonic phases, namely, crystalline solids exhibiting an enhanced ability to conduct protons, as demonstrated through electrochemical impedance spectroscopy measurement.

The extraction of valuable carbon-based products from CO2 reduction represents a promising route to reduce greenhouse gas emissions, promote circular economy practices, and facilitate the integration of energy storage sources such as Li-ion batteries (LIBs). Using such extremely valuable sustainable products obtained from the CO2 capture process can solve not only the global warming problems but also the high demand of the battery industry to provide graphite and highly conductive additives. Herein, a carbon nanomaterial (CNM) extracted from CO2 reduction treatment is used as the conductive additive in LIB graphite anode and lithium iron phosphate cathode. The electrodes are produced by casting, using both the conventional poly(vinylidene fluoride) binder, dissolved in N-methyl-2-pyrrolidone, and sodium alginate as a green, water-soluble, alternative binder. The electrochemical performance of the CNM-based electrodes is here compared to that of LIB cathodes and anodes produced with a commercial carbon additive. The electrodes featuring CNM offer electrochemical performance close to those of conventional electrodes in which commercial conductive additives are utilized.

Ion-Gated Transistors (IGTs) are a promising technology for neuromorphic computing, offering processing rates and energy efficiency. These devices support low-power training and operation of neural network algorithms while integrating both long-term and short-term modulation within a single system. The suitability of IGTs for neuromorphic applications depends critically on their time-resolved behaviour, governed by the doping mechanism. Specifically, the ionic permeability of the semiconducting channel dictates whether the device operates via electrochemical (three-dimensional) or electrostatic (two-dimensional) doping, leading to varying response times. This work focuses on controlling the response time of WO 3 -based IGTs using aqueous electrolytes—Li 2 SO 4 , Na 2 SO 4 , and K 2 SO 4 —as the gating media. We systematically study the effects of gate-source voltage (V gs ) pulse parameters (frequency, duration, and number) and sampling time on synaptic behaviour. These parameters are tuned to optimize ion intercalation and channel conductivity, enabling precise modulation of synaptic plasticity. Our findings demonstrate the tunability of WO 3 -based IGTs for neuromorphic applications, providing insights into the interplay between ion gating medium properties and channel dynamics. This work highlights the potential of these devices for energy-efficient and adaptive artificial synapses.

Electrochemical double-layer capacitors (EDLCs) play a critical role in high-power energy storage, offering exceptional durability and longevity for diverse applications. EDLCs typically utilize activated carbon electrodes combined with organic electrolytes, produced through cost-effective roll-to-roll manufacturing, and achieving operating voltages of approximately 2.7 V. Replacing toxic materials in electrode fabrication is critical for transitioning towards sustainable manufacturing practices. A key component in their production is the binder, which must ensure uniform coating, thermal and mechanical stability, optimal microstructural properties, electrochemical inertness, and environmentally friendly processing. Pullulan (PUL), a water-soluble polysaccharide, emerges as a promising alternative, offering reduced environmental impact and cost benefits. Our recent studies demonstrated the feasibility of PUL as a binder for aqueous processed EDLCs at the laboratory-scale. However, scaling up this process and validating it for large-scale EDLC electrodes remain open challenges. Here, we present a comprehensive investigation into the optimization of low-binder-content, high-mass-loading electrode manufacturing at both laboratory and pre-industrial scales. Moreover, a PUL electrospun membrane has been also investigated as separator. The optimized electrode formulations are validated in pouch cells with 20 cm2 electrodes, providing critical insights into the feasibility and scalability of the proposed supercapacitor configuration.

Lithium-ion batteries (LIBs) can play a crucial role in the decarbonization process that is being tackled worldwide; millions of electric vehicles are already provided with or are directly powered by LIBs, and a large number of them will flood the markets within the next 8–10 years. Proper disposal strategies are required, and sustainable and environmental impacts need to be considered. Despite still finding little applicability in the industrial field, recycling could become one of the most sustainable options to handle the end of life of LIBs. This review reports on the most recent advances in sustainable processing for spent LIB recycling that is needed to improve the LIB value chain, with a special focus on green leaching technologies for Co-based cathodes. Specifically, we provide the main state of the art for sustainable LIB recycling processes, focusing on the pretreatment of spent LIBs; we report on Life Cycle Assessment (LCA) studies on the usage of acids, including mineral as well as organic ones; and summarize the recent innovation for the green recovery of valuable metals from spent LIBs, including electrochemical methods. The advantage of using green leaching agents, such as organic acids, which represent a valuable option towards more sustainable recycling processes, is also discussed. Organic acids can, indeed, reduce the economic, chemical, and environmental impacts of LIBs since post-treatments are avoided. Furthermore, existing challenges are identified herein, and suggestions for improving the effectiveness of recycling are defined.

This investigation, combining both structural and spectroscopic analyses, sheds light on the intricate relationship between conduction properties and the initiation of dynamic motions within the anhydrous crystalline materials of 18-crown-6KHSO4 (1) and 18-crown-6RbHSO4 (2) and proves how the formation of supramolecular complexes is pivotal for inducing solid-solid transitions, leading to superprotonic phases, i.e., crystalline solids exhibiting an enhanced ability to conduct protons, as elucidated through impedance spectroscopic measurements. This multifaceted approach deepens our understanding of the phenomenon and sets the stage for further exploration and application in solid-state protonic conductors.

Ion-gated transistors using films of Li 4 Ti 5 O 12 and TiO 2 battery electrode materials interfaced with the ionic liquid [EMIM][TFSI] and the salt LiTFSI to study the doping mechanism during lithiation/delithiation considering possible structural changes.

Carbons derived from pyrolysis and activation of waste biomass are attracting much attention as components of energy technologies, such as batteries, supercapacitors and fuel cells. This experimental study focuses on the production of a high-surface-area biochar obtained from the treatment of lignin-rich waste of a biodigester plant, by applying KHCO3 as an activating agent. The pyrolysis-activation conditions were set by following the process by thermogravimetric analysis and by checking the purity and porosity of the resulting carbon by several analytical techniques. The best pyrolysis condition provided a microporous carbon featuring up to 1840 m2 g-1, which was demonstrated at a 25 g biodigestate batch-scale. Moreover, the production process was critically analysed by means of life cycle assessment to identify environmental hotspots and thus derive recommendations for process optimization. The impact of substance and energy-recovery and the use of renewable energy sources on the sustainability of the product was demonstrated in several scenarios, complemented by benchmarking and an outlook regarding further optimization needs. In the best case scenario, the global warming potential of the proposed biochar could be reduced to 15.9 kg CO2-eq per kg of LAC. The activating agent KHCO3 was dominant in almost all environmental impact categories, hence, a theoretical recovery process for this substance was suggested and evaluated via life cycle assessment.

Since the beginning of the 21st century, ecological, light weight and low-cost power sources devices with excellent mechanical flexibility are crucial to fulfill the requirements of emerging technologies for the new generation, including robots, foldable phones and wearable electronics. Herein, we report the integration of eco-friendly and biocompatible binders Polyvinyl alcohol (PVA) and Pullulan (Pu) for the straightforward manufacturing of flexible and sustainable carbon-based electrodes for supercapacitors applications. Furthermore, Glycerol (GCy) has been employed as a dual-purpose plasticizer agent for both electrode and electrolyte preparation, thereby minimizing manufacturing costs. Firstly, GCy content influence on the electrochemical performances and PVA-GCy/KOH films quality was investigated. Pullulan/Activated Carbon (Pu/AC) based supercapacitors have shown superior energetic performances in contrast to those achieved by the PVA/AC based ones. The Pu-based device exhibited a maximum aerial capacitance of 155 mF cm(-2) at 5 mV s(-1), and a maximum energy and power densities of 31.8 mu Wh cm(-2) and 34.3 mW cm(-2) respectively at 0.1 A g(-1). Furthermore, the device showed excellent stability behavior (>91 % of its initial capacitance after 9000 cycles). More importantly, the fabricated supercapacitor presented acceptable electrochemical performances when folded at different bending angles, opening the way to the practical applications of micro-storage and flexible embedded systems.