Search Results (189)

Developing sustainable lithium-ion batteries (LIBs) requires binder–carbon interfaces that combine mechanical compatibility, interfacial cohesion, and reduced environmental impact. In this work, density functional theory calculations were used to evaluate the interactions of representative binder monomers acrylonitrile (AN), pyrrole (PY), vinylidene fluoride (VDF), and tetrafluoroethylene (TFE) with pristine graphene and chitosan-functionalized graphene oxide (GO/chitosan). Structural, energetic, electronic, and topological features were analyzed using counterpoise-corrected interaction energies, frontier-orbital descriptors, molecular electrostatic potential maps, projected density of states, noncovalent interaction analysis, and quantum theory of atoms in molecules topology. Final interaction energies were obtained at the M06-2X/def2-TZVP level with Boys–Bernardi counterpoise correction to provide a more robust description of weak noncovalent adsorption. Most binder–surface interactions fall within a weak, near-thermoneutral adsorption regime. On pristine graphene, AN and PY exhibit weakly favorable adsorption, with minimum counterpoise-corrected interaction energies of −3.13 and −2.10 kcal mol⁻¹, respectively, whereas TFE and VDF show orientation-dependent, near-neutral behavior. GO/chitosan introduces oxygen-containing and amino functionalities that modify the adsorption balance, particularly for selected perpendicular configurations of fluorinated monomers, although the net stabilization remains modest. NCI, QTAIM, MEP, and PDOS analyses indicate that surface functionalization increases the chemical heterogeneity and directionality of local contacts; however, these local descriptors do not necessarily translate into strong global adsorption energies. Overall, the results identify GO/chitosan as a chemically tunable interface for binder–carbon compatibility in LIB electrodes and demonstrate the importance of triple-ζ, counterpoise-corrected calculations for evaluating weak binder–surface interactions. Full article

Fast-charging lithium-ion batteries require graphite anodes with low ionic transport resistance, yet systematic links between electrode manufacturing parameters and fast-charge performance remain scarce. This study shows that twin-screw extrusion (TSE) process conditions control electrode tortuosity, the geometric complexity of ionic pathways, by reshaping the binder network architecture without altering active material integrity. A central composite experimental design combined with multi-scale diagnostics identifies pore network tortuosity as the primary transport bottleneck. The optimized mild kneading condition (K4: 60 $\mathrm{wt}\%$ kneading zone solids, 7% kneading length, gentle screw design) reduces the 8–80% state-of-charge (SOC) charging time by $14.9$% relative to the intensive baseline (B1–B3: 70 $\mathrm{wt}\%$, 50% kneading length), matching conventional batch mixing. Regression analysis confirms a strong correlation between tortuosity and fast-charge performance ($R^2=0.86$), whereas the correlation with charge-transfer resistance is weaker ($R^2=0.59$). Mechanistically, mild kneading promotes reversible, sterically stabilized carboxymethyl cellulose (CMC) networks consistent with extended “loop-tail” polymer conformations. Intensive kneading is consistent with the formation of bridging gels that fail to arrest binder migration during drying and clog surface pores. A Pore-Homogeneity Index (PHI), derived from mercury porosimetry, quantifies the resulting microstructural heterogeneity, correlates with tortuosity ($R^2=0.76$), and characterizes pore network uniformity. The results identify local stress intensity as a primary factor influencing binder network formation and support tortuosity as an adjustable design parameter in continuous anode processing. Full article

The high-voltage spinel ${\mathrm{LiNi}}_{0.5}{\mathrm{Mn}}_{1.5}{\mathrm{O}}_4$ (LNMO) is a promising cobalt-free cathode material for lithium-ion batteries, yet its integration as a binder-free thin film on metallic current collectors via simple solution routes remains underexplored. Here, LNMO films were synthesized on 304 stainless steel (SS304) by metal–organic decomposition (MOD) from metal–acetate precursors in ethanol, followed by spin-coating and annealing at 500, 600, and 700 °C under flowing ${\mathrm{O}}_2$. The films were characterized by XRD, FESEM–FIB cross-sectioning, EDS, and XPS, and tested as binder-free cathodes by cyclic voltammetry and galvanostatic charge/discharge. All samples are dense, approximately 1.9 μm thick, and crystallize in the disordered spinel phase. The LNMO crystallite size increases from 21.9 to 43.8 nm between 500 and 700 °C, while the grain size also shows a temperature dependence, increasing the average size from 25 up to 56 nm in diameter. XPS confirms ${\mathrm{Mn}}^{4+}$ as the dominant manganese surface species (45–49%) across all samples. The films deliver reversible discharge capacities of 92, 92, and 70 mAh ${\mathrm{g}}^{-1}$ at 0.1 C for LNMO500, LNMO600, and LNMO700, respectively, with well-defined ${\mathrm{Ni}}^{2+}{\mathrm{/Ni}}^{3+}$ and ${\mathrm{Ni}}^{3+}{\mathrm{/Ni}}^{4+}$ redox peaks at 4.7 and 4.8 V. DFT calculations independently predict a voltage plateau at ∼4.7 V for $0.2\le x\le 1$, in agreement with the experimental profiles. These findings establish MOD as a viable, vacuum-free route to the synthesis of nanostructured LNMO cathodes. Full article

This study presents a novel approach to the use of kraft lignin in electrochemical energy sources, with a focus on its use as anode material. The key novelty of this study is the use of natural casein as an innovative binder in electrode production, offering a sustainable and efficient alternative to conventional binders. The carbonaceous material was obtained from kraft lignin by two heat treatments at a relatively low temperature of 300 °C—one in a nitrogen atmosphere and the other in air. The results indicate that carbonization at this lower temperature provides promising electrochemical properties while improving cost-effectiveness and energy efficiency compared to higher temperature processes. Additionally, wettability analysis based on contact-angle measurements revealed substantially improved electrolyte affinity for casein-based electrodes, which correlates with their enhanced electrochemical performance. The study showed promising performance of the developed electrodes as follows: a capacity of 67 F g⁻¹ for supercapacitor applications, 250 mAh g⁻¹ for lithium-ion batteries, and 50 mAh g⁻¹ for sodium-ion batteries. These results confirm that kraft lignin, in combination with casein as a binder, is an environmentally friendly and economically viable alternative to traditional electrode materials. Full article

The need for the rapid advancement of lithium-based energy storage technologies continues to outpace progress in materials development and manufacturing, creating a widening gap between laboratory-scale innovation and industrial deployment. There is a need to examine the key materials and processing challenges that limit the performance, cost-effectiveness, and sustainability of next-generation lithium batteries. For material considerations, many commonly used electrodes face issues of volumetric expansion and performance degradation over charging cycles. To address these issues, binders are a crucial component to consider as they adhere active materials to the electrodes, and their structure can be altered to mitigate undesirable effects from these components. Hence, the selection and exploration of alternative binders are becoming increasingly important in the pursuit of longer-lasting and safer Li-batteries. From a manufacturing perspective, current production lines rely on multistep, energy-intensive processes, e.g., from slurry-mixing to cell assembly, that elevate costs and complicate scale-up. Emerging chemistries incorporating nanomaterials or solid-state components face additional barriers related to yield, process control, and defect management, all of which can exacerbate safety risks related to processing during production and thermal runaway in produced batteries. End-of-life considerations, including disassembly, recycling, and the safe handling of toxic materials, further contribute to the technological and logistical complexity of large-scale deployment. The field is moving toward sustainable material alternatives, more efficient and adaptive manufacturing routes, and advanced technologies such as solid-state electrolytes and nanostructured electrodes. Together, these developments provide a roadmap for overcoming current bottlenecks and enabling the next generation of high-performance, safe, and sustainable lithium battery technologies. This review examines the progress made in finding alternative materials and synthesis methods for the optimization of lithium battery cells, with a focus on the development of novel binders, slurry synthesis and manufacturing framework. In addition, the advantages and limitations of the alternative binder materials and processes are also explored, with a focus on scalability for manufacturing, safety concerns, sustainability and end-of-life challenges. Full article

As the global demand for lithium-ion batteries (LIBs) continues to rise, battery recycling has become a critical strategy for mitigating resource depletion, minimising environmental impact, and advancing a circular economy. However, recycled electrode materials, particularly cathode and anode powders, often contain residual impurities such as transition metals (e.g., Cu, Fe, Al), polymeric binders (e.g., PVDF), and electrolyte decomposition products. These contaminants can significantly impair the electrochemical performance, thermal stability, and overall safety of newly manufactured cells. This study aims to systematically investigate the nature, origin, and impact of impurities in recycled cathode and anode materials. A suite of analytical techniques, including inductively coupled plasma mass spectrometry (ICP-MS), infrared spectroscopy (IR), scanning electron microscopy with energy-dispersive spectroscopy (SEM-EDS), and thermogravimetric analysis (TGA), will be employed to quantify impurity levels and assess material integrity across various recycling streams. The findings are expected to inform the establishment of impurity threshold limits for battery-grade recycled materials and guide the development of enhanced purification protocols. Ultimately, this research will support the production of safer and more reliable second-life batteries, offering valuable insights to recyclers, manufacturers, and regulatory bodies committed to sustainable energy storage technologies. Full article

The electric vehicle revolution has created an urgent need for lithium-ion battery (LIB) recycling, with projections exceeding 11 million tons of end-of-life batteries annually by 2030. However, progress toward a circular economy remains fragmented. This perspective article introduces the concept of a ‘Recycling Trilemma,’ arguing that technological advancements in material separation are systematically undermined by economic volatility and regulatory fragmentation. While current literature focuses on isolated domains—chemistry, business models, or policy—this work provides a systems-level synthesis. By analyzing the friction points between material science (e.g., binder removal, impurity sensitivity), economic realities (e.g., logistics costs, LFP profitability), and regulatory frameworks (e.g., EU vs. US divergence), we propose that true circularity requires synchronized design-for-recycling, market stabilization mechanisms, and harmonized digital product passports. The paper concludes that overcoming the trilemma demands a shift from isolated fixes to integrated, cross-sectoral coordination. Full article

The strong adhesion between cathode materials and aluminium (Al) foil substrates presents a significant challenge in the recycling of spent lithium-ion batteries (LiBs). Conventionally, high temperatures and high concentrations of costly organic solvents such as N-methyl-2-pyrrolidone (NMP), dimethylacetamide (DMAC), dimethylformamide (DMF), and dimethyl sulfoxide (DMSO) are used to enhance ultrasonication-based delamination. In this study, a novel, eco-efficient approach was demonstrated for delaminating cathode materials from Al foil using a low-concentration organic citric-acid-assisted low-power ultrasonic treatment coupled with a gentle, low-power-per-volume mechanical mixing system at room temperature. The separation mechanism was attributed to the structure disruption, possibly swelling, of the polyvinylidene fluoride (PVDF) binder using low-concentration citric acid and the cavitation effects induced by ultrasound. Key parameters influencing the delamination efficiency included the solvent type, temperature, ultrasonic power, and treatment duration. Under optimised conditions, citric acid was used as the sonication reagent, with a process temperature of 20 °C, 60 W ultrasonic power, and 80 min of ultrasonication; a delamination efficiency of approximately 92% was achieved. The recovered cathode materials exhibited low agglomeration, favouring subsequent leaching processes. This work proposes an environmentally friendly and effective method for cathode and Al foil recovery from spent LiBs, integrating manual dismantling, ultrasonic treatment, and material separation. Full article

The rapid expansion of lithium-ion battery (LIB) applications and the imminent surge in end-of-life batteries have intensified the demand for efficient, scalable recycling technologies. Physical separation of cathode and anode materials is a crucial pretreatment step that enables high-value metal recovery and direct material regeneration. This review critically examines recent advances in three major physical separation technologies—magnetic separation, gravity separation, and flotation—for processing spent LIB electrodes. Rather than offering a descriptive summary, the review systematically analyzes separation mechanisms, key controlling parameters, and pretreatment strategies across representative cathode chemistries, including LiFePO₄ (LFP), LiCoO₂ (LCO), and Ni–Co–Mn (NCM) systems. Particular emphasis is placed on emerging flotation-enhancement strategies, such as nanobubble-assisted and ultrasonic-enhanced flotation, and their underlying mechanistic roles in improving selectivity and recovery. Comparative evaluation indicates that magnetic separation has reached industrial maturity for LFP–graphite systems but remains chemistry-specific. Gravity separation is effective for coarse particles and centrifugal-assisted graphite recovery yet shows limited selectivity for fine particles. Flotation has become the dominant research focus for complex, fine-particle separations due to its tunable surface chemistry. Despite significant laboratory progress, challenges remain, including incomplete binder removal, limited understanding of electrode surface reconstruction during pretreatment, fine-particle entrainment, and the gap between bench-scale research and industrial implementation. Future research priorities include green reagent development, intelligent separation control, and integration with direct regeneration routes to advance closed-loop LIB recycling towards sustainable development. Full article

Silicon-based materials offer exceptional theoretical capacity for lithium-ion batteries (LIBs), but their practical application remains severely hindered by large volume expansion, low electrical conductivity, and unstable solid electrolyte interphase (SEI) formation during cycling. Herein, a binder-free silicon-containing carbon composite anode (denoted as CP-Si@C-4, where CP represents the conductive carbon paper substrate) is designed: carbon constitutes the structural and conductive framework, while silicon nanoparticles serve as a functional alloying component contributing characteristic lithiation/delithiation behavior. This framework comprises a conductive carbon paper (CP) scaffold, a resin-derived carbon matrix for homogeneous silicon dispersion, an interconnected carbon nanotube (CNT) network enabling long-range electron transport, and a conformal chemical vapor deposition (CVD) carbon layer for interfacial stabilization. Rather than simply increasing the overall carbon content, a series of control electrodes with distinct carbon configurations are deliberately designed to decouple the respective roles of bulk stress buffering and particle-level interfacial stabilization during cycling. The results indicate that functionally differentiating and coordinately regulating these two functions is critical for achieving durable binder-free silicon-containing carbon composite anodes. Benefiting from this cooperative multidimensional carbon architecture, the optimized CP-Si@C-4 anode delivers an initial Coulombic efficiency (ICE) of 86.3% and maintains a reversible capacity of ~990 mA h g⁻¹ at 2 A g⁻¹ after 1000 cycles. This work provides a structural design concept for improving long-term stability in binder-free silicon-containing carbon composite anodes. Full article

The sustainable recycling of valuable metals from spent lithium-ion batteries (LIBs) is imperative for closing the resource loop. This study presents an integrated strategy for the stepwise recovery of metals from spent cathode sheets by in situ thermal reduction and selective leaching. The in situ thermal reduction converted the cathode material into a mixture of Li₂CO₃, LiAlO₂, Ni, Co, NiO, and CoO while simultaneously liberating the cathode materials from the Al current collector through binder removal. A combined process of water leaching, wet sieving, and filtration successfully achieved the separation and enrichment of Li-rich aqueous solution (near 60% Li), Al-rich coarse fraction (over 87% Al), and fine powder enriched with transition metals (over 90% of Ni, Co, and Mn). The pyrolysis gases released from binder decomposition were the key driver for forming Li₂CO₃, whereas the concurrent generation of LiF and LiAlO₂ limited direct water leaching efficiency. An alkaline leaching step was therefore introduced to co-extract Al and the associated Li from LiAlO₂, followed by an acid leaching step that recovered over 96% of the transition metals from the treated residue without external reductants. Complete mass balance analysis shows that the integrated process achieved overall recoveries of 91.86% for Li, 91.93% for Ni, 92.23% for Co, and 92.61% for Mn from all the combined leachate streams. Consequently, this work provides a reagent-saving, stepwise hydrometallurgical process for the comprehensive recycling of valuable metals from spent LIBs. Full article

Heteroatom functionalization of graphene is an effective strategy for designing more sustainable lithium-ion battery electrodes, as it can tune both interfacial adhesion and the electronic features of the carbon lattice. In this work, we investigated the interfacial compatibility between three graphene sheets—pristine graphene, graphene doped with one nitrogen atom (Graphene–N), and graphene doped with one sulfur atom (Graphene–S)—and three lignocellulosic binders (carboxymethylcellulose (CMC); coniferyl alcohol (LcnA); and sinapyl alcohol (LsiA)) using density functional theory (DFT). Geometries were optimized using CAM-B3LYP and M06-2X in combination with the LANL2DZ basis set, while ωB97X-D/LANL2DZ was employed for dispersion-consistent single-point refinements. The computed adsorption energies indicate that all binder–surface combinations are thermodynamically favorable within the present finite-model framework (ΔE_int ≈ −22.6 to −31.1 kcal·mol⁻¹), with LSiA consistently showing the strongest stabilization across surfaces. Nitrogen doping produces a modest but systematic strengthening of adsorption relative to pristine graphene for all binders and is accompanied by electronic signatures consistent with localized donor/basic sites while preserving the delocalized π framework. In contrast, sulfur doping yields a more binder-dependent response: it maintains strong stabilization for LSiA but weakens LCnA relative to pristine/N-doped sheets, consistent with an S-induced local distortion/polarizability pattern that can alter optimal π–π registry depending on the adsorption geometry. A combined interpretation of adsorption energies, electronic descriptors (including ΔE_gap as a model-dependent HOMO–LUMO separation), and topological analyses (AIM, ELF, LOL, and MEP) supports that Graphene–N provides the best overall balance between electronic continuity and chemically active interfacial sites, whereas Graphene–S can enhance localized anchoring but introduces more heterogeneous, lone-pair–dominated domains that may partially perturb electronic connectivity. Full article

Waterborne polyurethane (WPU) and waterborne poly(urethane-urea) (WPUU) dispersions allow safer and more sustainable manufacturing of rechargeable batteries via water-based processing, while offering tunable adhesion and segmented-domain mechanics. Beyond conventional roles as binders and coatings, WPU/WPUU chemistries also support separator/interlayer and polymer-electrolyte designs for lithium-ion and lithium metal systems, where interfacial integrity, stress accommodation, and ion transport must be balanced. Here, we review WPU/WPUU fundamentals (building blocks, dispersion stabilization, morphology, and film formation) and review prior studies through a battery-centric structure–processing–property lens. We point out key performance-limiting trade-offs—adhesion versus electrolyte uptake and ionic conductivity versus storage modulus—and relate them to practical formulation variables, including soft-/hard-segment selection, ionic center/counterion design, molecular weight/topology control, and crosslinking strategies. Applications are reviewed for (i) electrode binders (graphite/Si; cathodes such as LFP and NMC), (ii) separator coatings and functional interlayers, and (iii) gel/solid polymer electrolytes and hybrid composites, with a focus on practical design guidelines for navigating these trade-offs. Future advancements in WPU/WPUU chemistries will depend on developing stable, low-impedance interlayers, enhancing electrochemical behavior, and establishing application-specific design guidelines to optimize performance in lithium metal batteries (LMB). Full article

The adoption of silicon-graphite composites as anode materials for the next generation of lithium-ion batteries with enhanced specific capacity requires complex technological efforts in order to mitigate the problem of the quick performance fading of electrodes due to the mechanical degradation of materials. The matter is currently being addressed in terms of electrolyte components, polymer binders, materials structure and morphology itself, as well as current collector design, which differ greatly in cost and scalability. The present work describes the efficacy of Cu foil perforation—a simple, low-cost, and easily scalable approach—as a means of Si/C composite anode performance stabilization during extensive charge-discharge cycling. The NMC||Si/C pouch-type full cells demonstrated over 90% of initial capacity retention after 100 charge-discharge cycles in the case of a 250 µm perforated Cu foil used as a current collector, compared to only 60% capacity left in the same conditions for plain Cu foil as an anode. The obtained result is related to the prevention of anode material delamination off the foil surface as a result of silicon expansion and contraction, which is achieved through the formation inter-penetrating metal-composite structure and the presence of “stitches”, connecting and holding both sides of the electrode tightly attached to the current collector. Full article

Silicon is widely recognized as a next-generation anode owing to its exceptional theoretical capacity, yet its practical deployment in lithium-ion batteries is constrained by severe volume expansion, particle fracture, loss of electrical percolation, and solid electrolyte interphase layer instability. Polymer-based strategies have emerged as accessible solutions to engineer extensive volume changes and interfacial compatibility, while preserving pathways for charge transport. Viscoelastic polymer binders dissipate stress, catechol-inspired chemistries strengthen adhesion and tailor interphases, and conductive polymers can function simultaneously as binder, electronic additive, and artificial SEI. This review describes these approaches through a structure–process–performance perspective, emphasizing practically relevant metrics, such as initial capacity, initial Coulombic efficiency, and long-term cycling stability. We organize the main section into (i) dopamine-derived interfacial engineering, (ii) self-healing three-dimensional network binders, and (iii) conductive-polymer-based designs. In the last section, we articulate the functional requirements of polymers in silicon anodes, outline the ideal structural designs, and provide forward-looking avenues for future lithium-ion battery anode research. Full article