The rapid growth of Li-ion Batteries (LIBs), especially in the automotive sector, raises urgent concerns regarding End-of-Life (EoL) management and the secure supply of Critical Raw Materials (CRMs), including lithium, cobalt, and nickel. To mitigate risks of resource scarcity and environmental impact, sustainable collection and recycling practices are essential to support the transition toward a circular economy, enabling the recovery of both metallic and non-metallic components. A zero-waste approach to LIB recycling is therefore emerging as a key priority. Industrial innovation and academic research are deeply interconnected in this field. Industry depends on scientific discoveries to scale up efficient recycling technologies, while academia is driven by challenges arising from industrial practice and regulatory demands. This reciprocal relationship accelerates the development of advanced recycling strategies capable of addressing technical and economic barriers. This review provides an overview of LIB recycling in Europe, focusing on the evolving legislative framework designed to regulate the proper management of spent batteries and promote the recovery of CRMs. Current industrial practices are discussed with particular attention to their limitations, alongside emerging academic solutions that could redefine the efficiency, sustainability, and economic viability of LIB recycling.

Recycling of critical raw materials from lithium-ion batteries is becoming an unavoidable necessity. Pyro-and hydrometallurgy, which are the processes currently available at industrial level, have relevant issues in terms of sustainability. Solvometallurgy can solve some problems, chiefly about energy and water consumption. Here we report on the use of a ternary deep eutectic solvent (DES) for the microwave-assisted extraction of Lithium, Nickel and Cobalt from a commercial cathode active material (CAM). The optimal composition of the DES and the best experimental parameters are determined by careful experimental design. The most effective DES composition of choline chloride, lactic acid and urea in molar ratio is 1:3:1. The optimal working conditions are 70 degrees C, an extraction time of 15 min, and a microwave power of 100 W. Under these conditions, the mixture enabled the recovery of more than 95 % of Lithium and over 99 % of Nickel and Cobalt. The extracted metals are subsequently processed to obtain precursors suitable for the synthesis of a new CAM, including 15 % of resynthesized material. The cathode made with a blend of commercial and resynthesized cathode active material gives the same performance of commercial one.

Bioactive coatings that combine antibacterial and pro-osteogenic components are gaining increasing attention for their ability to prevent bacterial adhesion and surface colonization while promoting integration with host tissues. This study focused on designing and developing antimicrobial nanoparticle (NP)-loaded chitosan films doped with Sr2+-enriched hydroxyapatite (SrHA) as bioactive coatings for orthopaedic medical devices. At this purpose, blank and thymol-loaded PLA nanoparticles were produced by microfluidics techniques, and the impact of the different process parameters was evaluated. The results show that nanosized particles ranging from 150 to 250 nm were produced across all PLA concentrations tested and thymol was delivered into the nanoparticles with a drug loading (DL%) of 5.8% (±0.7 SD). Moreover, the SrHA was synthetized and characterized comparing it's physical-chemical properties with that of a commercial HA. In detail, the results confirm the incorporation of Sr2+ within the apatite structure with a weight ratio % around the 30%. Then, the crystalline pattern of SrHA was also investigated resulting in a crystalline structure with higher amorphous domains than those of the HA structure highlighted by the broadened peaks to the XRPD pattern due to the substitution of Ca2+ with Sr2+ characterized by larger atomic radius. Chitosan films incorporating thymol-loaded NPs and SrHA were produced using solvent casting technique and characterized through a multidisciplinary approach. The mechanical properties, along with the favourable morphology and topography of the coatings, appeared to enhance the biological response. The resulting systems supported mesenchymal stem cell proliferation and promoted the expression of genes related to osteoinduction while also exhibiting antimicrobial activity against both Gram-positive and Gram-negative bacterial strains. Preclinical evaluations provided sufficient evidence of efficacy and safety, paving the way for their use as pro-osteogenic and antimicrobial coatings for orthopaedic devices as hybrid multifunctional coatings providing antimicrobial protection and pro-osteogenic stimulation offering a novel route to address two major clinical challenges such as early-stage bacterial contamination and insufficient osteointegration.

Spinel structures are promising cathodes for Lithium-ion batteries due to good functional performance and sustainability. LiMn2O4 is the most investigated composition, despite some drawbacks: i) Jahn-Teller distortion involving Mn (III), and ii) partial dissolution of Mn (II) upon cycling. Here, we report on spinel compositions (LiMxMn1-xO4) where Mn is partially substituted by Fe (III) to decrease the Mn (III) amount. This system was doped with small amounts (<0.05 at.%) of Zr (IV) and decorated with ZrO2 nanoparticles with a synergistic role: i) to replace electrochemically active cations with pillar ions and stabilize the spinel structure during cycling; ii) to protect the electrode/electrolyte interface and reduce the TMs dissolution upon cycling. Li(Mn1.5-xFe0.5 Zr-x)O-4 (LMFZ) was synthesized through solid-state reaction and characterized by multi-technique approach. The best composition (LMFZ2) exhibited very high structural stability with no change in lattice parameters and very low Mn (II) dissolution rate upon prolonged cycling at 0.5C. When cycled at 0.08C at 2.3-4.3V, this cathode delivered stable specific capacity exceeding 140 mAh g(-1). Good capacity retention > 87% was determined after 160 cycles at both low and higher C rates (namely 0.5C and 2C). Superior electrochemical properties were observed for the Zr-doped cathode with respect to LiMn1.5Fe0.5O4.

The increasing demand for Lithium-ion batteries (LIBs) in several applications has led to a substantial rise in their production, posing risks in the supply of critical raw materials (CRM, e.g.: Li, Ni, Co). Additionally, improper disposal of end-of-life batteries can lead to environmental pollution and loss of technological value stressing the necessity for sustainable recycling. Current methods involve shredding batteries into a black mass, further processed via pyrometallurgy (energy-intensive) and/or hydrometallurgy with inorganic acids (environmentally hazardous) to recover CRMs. A more refined approach to LIBs recycling includes the dismantling and the sorting of their components, allowing for a targeted extraction. The spent cathodes recycling process here presented involves the simultaneous delamination from the current collector and the leaching (>95 %) of the cathode active material (CAM) in a citric acid solution, enabling also the recovery of Polyvinylidene fluoride (PVDF) and Carbon filler as unleached residues, which can be used as a composite binder for new electrodes manufacturing. Lastly, metals are recovered with high yields (>85 %) as precursors, used to resynthesise fresh CAM and close the recycling loop. To validate the proposed strategy, the recycled CAM was used in a new cathode manufacturing followed by its functional characterization in a half-cell configuration, achieving high coulombic efficiencies (>99.2 %) and satisfying specific capacities upon cycling (initial capacity: 115 mAh g(-1)).

The scavenging mechanism for H2O and HF by HKUST-1 and Al2O3 nanoparticles, respectively, in a double-scavenger Janus separator.

The increasing demand for Lithium-ion batteries (LIBs) in several applications, from consumer electronics to electric vehicles (EVs), has led to a substantial rise in their production, posing serious risks in the supply of critical raw materials (CRMs, e.g.: Li, Ni, Co, and graphite). Additionally, an improper disposal of end-of-life (EoL) batteries can lead to environmental pollution and loss of technological value (e.g., burning of electrolyte and fluorinated binder) stressing the necessity for a sustainable recycling. Current methods involve shredding whole batteries into a black mass, from which the components are separated through pyrometallurgy (energy-intensive) or hydrometallurgy with inorganic acids (potentially harmful to environment and workers). However, a more refined approach to LIBs recycling involves the dismantling and the sorting of their components, allowing for a targeted extraction. Here, a recycling process for spent cathodes is presented, involving the delamination from the current collector and the leaching of the cathode active material (CAM) into the same citric acid (CA) solution; this also enables the recovery of PVDF and Carbon conducting filler as a residue of the leaching. Lastly, the metals recovered as precursors, are used to resynthesize fresh CAM, thus closing the recycling loop.

Transition metal fluorophosphates of general formula Na2MPO4F (M = transition metal) are interesting cathode materials for Na-ion batteries (NIBs), thanks to predicted high intercalation voltages and high theoretical capacities. However, the practical applications of several compositions in this family of compounds is limited by effective capacities lower than the theoretical ones and by high capacity fading, particularly at high charging rates. Thanks to the synergy of a broad spectrum of experimental and theoretical techniques, this work presents an extensive characterization of the electrochemical behavior of the prospect cathode material Na2-xMnPO4F (x = 0, 0.5, 1 and 2). Ab initio calculations, performed using Hubbard-corrected Kohn-Sham density functional theory (DFT) according to the DFT + U + V scheme, confirmed that the calculated intercalation voltages for the NaMnPO4F/MnPO4F couple are outside the stability window of conventional liquid electrolytes, thus limiting the material's performances to the extraction of 1 Na-ion per formula unit. To investigate the role of Na-ion diffusion on the electrochemical properties of this system, bond valence site energy (BVSE) analyses and molecular dynamics were used to identify the main diffusion pathways, and to correlate their energetics to the distortion of the Mn-O/F octahedra at various Na concentrations. The resulting 3D diffusion pathway is characterized by a relatively high diffusion coefficient for Na-ion in the perfect crystal, suggesting that the experimentally observed performances, lower than expected particularly at high charging rates, can only marginally be attributed to limited Na-ion diffusion in the system.

The demand for lithium-ion batteries (LIBs) is posing challenges in the management of end-of-life (EoL) systems and supply of critical raw materials. Such challenges can be addressed by recycling EoL LIBs through sustainable processes, involving metallurgy to recover higher-value metals like Co, Ni, and Li. Pretreatment strategies allowing to reclaim other valuable materials-such as graphite, binders, and electrolytes-are also crucial to enhance the overall recycling efficiency. Despite the strategic relevance of graphite in the battery supply chain, its recovery and reuse remain poorly explored. Herein, a sustainable closed-loop approach for the reclamation and reuse of graphite from EoL LIBs black mass is proposed, exploiting a low-impact froth flotation based on green chemicals. The recovered graphite is purified through a mild chemical leaching by natural organic acids and thermally treated to restore its microstructure from damages induced by the aging phenomenon. The regenerated material is characterized by multi-sample technique approach, demonstrating high separation efficiency (>96% yield) and purity (>99.6%). The direct recycling process is validated by reusing the reclaimed graphite as secondary anode active material in new cells, showing functional performance comparable to those of the commercially available material.

Among the different cathodes studied for Sodium-Ion Batteries (SIBs), the P2-layered oxide structure has garnered significant attention due to its electrochemical properties. However, several critical issues must still be addressed to enable large-scale commercialization, including the numerous phase transitions that the structure undergoes during cycling at high potentials (4 V) and the low Na content in the pristine material. In this work, starting from the promising and sustainable Na0.67Mn0.5Fe0.5O2, we developed new cathodes by partially replacing Fe with Mg. In addition to studying the role of Mg(ii), a cation known for its stabilizing properties, we also evaluated the influence of two different synthesis methods on the structural and functional properties. In particular, spray-drying proved to be very promising compared to the conventional solid-state synthesis, as it leads to materials with morphology and microstructures more compatible with application as cathodes for batteries. The calculated Na diffusion coefficient (DNa+) is more than two orders of magnitude higher for P2-Na0.67Mn0.5Fe0.3Mg0.2O2 prepared by spray-drying than that by the solid-state synthesis (10-8vs. 10-10 cm2 s-1). In line with this result, the capacity retention after 100 cycles @ 1C is also significantly higher (72% vs. 81%). Compared with P2-Na0.67Mn0.5Fe0.5O2, Mg(ii)-doping significantly improves the cathodic performances of the spray-dried materials, increasing capacity retention after 200 cycles at 1C from 39% to 69%. In conclusion, we confirmed that the choice of the correct synthesis route, combined with optimization of elemental composition, plays a crucial role in the development of high performance materials for SIBs.

Lithium ion-battery (LIB) technology, since its introduction in late 70s, rapidly imposed itself as the undisputed ruler of portable power and is continuously evolving. Out of the several chemistries available, LiFePO 4 (LFP) is regarded as one of the most promising. While compromising in terms of energy density and easiness of control, due to its inherently flat discharge curve related to a phase-transition behavior, it stands out for environmental sustainability, exceptional power density, satisfying lifetime and thermal stability. However, due to its relatively recent development, the fundamentals of its operation and degradation are still debated and seldom evaluated after real-life operation. De-tackling the interplay effects between the two electrodes and the electrolyte makes the topic further complex, especially when it comes to real-life aging and to enabling an effective distinction of each component’s contribution with non-invasive, in-situ and industrially viable diagnostics. In the framework of AutoMAT EU project, aiming at developing aging-aware circular-economy oriented post-use management strategies for LIB, real-life aged samples are extensively investigated. Their reusability in a circular perspective is a hot topic to sustainability, especially considering EU supply-chain, but requires understanding “how” batteries are aged rather than only “how much” they are, enabling a physically consistent state of health estimation. In this work, several modules of high-power LFP cylindrical cells, which were field-operated in a hybrid bus transport application for as much as 9 years, are selected and analyzed to assess their possible reusability. Cells selected at opposite aging-state have been harvested and applied to detailed electrochemical characterization, including q-OCP based analysis (DVA) and impedance assessment (EIS) as a function of battery SoC and temperature. Analysis reveals a surprisingly low residual capacity (80% down to 45%), with satisfying consistency with operational field-data, and good residual power. Significative in-module heterogeneity in aging is identified, with a pattern attributable to cells location beneath the modules, prompting the criticality of temperature-driven inhomogeneity during real-life operation. DVA enables to identify a loss of lithium inventory (LLI)-dominated aging (up to 45%) coupled with a non-negligible loss of active material at negative electrode (LAMn, up to 25%), consistent with lost capacity. Also, considering the absence of any distinctive features attributable to LFP electrode due to its flat-shaped OCP curve, an innovative derivative analysis specifically focusing on highly-delithiated LFP footprint permits to estimate a non-dominating presence of LAM at positive electrode (LAMp, lower than 10%), confirming its inner stability. EIS permits a step further into losses, showing increased resistance of the impedance spectra at high and intermediate frequencies, attributable to an increased ionic and charge transfer (RCT) resistances, while mass-transport-related region at low frequency appears roughly unchanged. These signs are consistent with worsened electrolyte ionic conductivity and a decreased performance of the electrochemical reactions, with a stable bulk diffusivity. Cells are then opened and harvested materials, including both the electrodes and electrolyte, are electrochemically tested in half-cell and T-cell configuration and analyzed ex-situ, for individual evaluation of components aging state. Electrolyte analysis revealed significant degradation over time: GC-MS identified a reduction of DMC and EMC carbonates coupled with the formation of secondary products such as DEC, indicating solvents decomposition. DSC analysis showed changes in the physical behaviour of aged electrolytes which is consistent to a decay in ionic conductivity. ICP-OES is adopted to estimate dead lithium amount in harvested material, while SEM+EDX and TGA are used to evaluate electrodes and separator morphology and composition change. The pristine negative electrode displayed a distinct flake-like structure with high carbon percentage content, while aging progressively leads to the formation of a thick and dense surface layer of salts and fluorinated electrolyte passivation products. Such electrolyte-originated layer is suspected to lead to porosity clogging in the electrode, interestingly contributing to decrease its active area, consistently to the identified trends in the electrochemical characterization (LAMn presence and RCT increase). Interestingly, lost active area appears recoverable after washing with solvents, as demonstrated in dedicated tests in T-cell configuration, demonstrating the reversibility of the mechanism and enabling possible recovery strategies. Interpretations are supported by physical model-based simulations on q-OCP and non-equilibrium measurements, permitting estimation of physical parameters related to aging. Aged cells measurements are interpreted with appositely developed q-OCP and P2D physical models, provided with heath exchange, demonstrating a decrease of electrolyte conductivity and surface area consistently meeting the experimental trends. This work enables a further deep-dive in severe real-life aging in LFP batteries, seldom present in the literature, enabling a physics-based understanding of the contribution of each component to overall battery degradation enabled by advanced electrochemical diagnostics and physical modelling. Figure 1

Quasi-solid polymer electrolytes (QSPE) are expected to lead to technological breakthroughs in the development of Li metal batteries, implementing functional properties (e.g., power density, safety, stability). QSPEs are systems where small amounts of liquid phase are chemically/physically entrapped into solid polymer matrix, resulting in effective combination between liquid-like transport and solid-like mechanical behaviour. The presence of a polymer backbone allows the introduction of smart functionalities, such as self-healing units, capable to repair spontaneously physical damages from mechanical stress. Here, we produce new QSPEs with self-healing functionalities whose repairing mechanism involves dynamic multiple hydrogen bonding. These electrolytes consist of: i) a blend of a fluropolymer (mechanically strong network) and ureidopyrimidinonetelechelic (repairing functionality); ii) dual-salt liquid electrolyte. QSPE including 9 wt% of liquid electrolyte shows outstanding ionic conductivity exceeding 1 mS cm-1 at 30 degrees C, wide electrochemical stability above 5.2 V and great mechanical strength, despite the presence of small liquid fraction. These properties are paired to excellent self-healing performances capable to recover conductivity decays and internal short circuits caused by dendrite penetration across the electrolytes. The self-healing QSPE was tested in LFP/Li cell at 40 degrees C. Higher thermal resistance against thermal abuse and improved functional performances were delivered compared to the liquid electrolyte.

Metal-halide superionic conductors are promising electrolytes for solid state Li-ion batteries. Their transport properties may be effectively influenced by doping and a synthetic approach. In this study, a combination of experimental (neutron and X-ray diffraction, total scattering techniques, solid state NMR, impedance spectroscopy) and computational techniques is used to investigate the Li3InCl6 system and, in particular, the effect of Nb substitution on the In site. A maximum conductivity (0.46 mS cm(-1) at room temperature) is found for 10% atomic substitution of Nb for In. The increase in conductivity due to doping is primarily associated with an increase in charge carrier concentration (i.e., Li vacancies). Computational modeling highlights the role of point and extended defects on the transport properties of this class of materials and corroborates the experimental finding of 3D diffusion in this layered structure, clearly supporting the choice of a highly disordered structural model to describe the average and the local structure of Li3InCl6.

The Li-ion batteries (LIBs) penetration in the automotive market makes more urgent the boosting of zero-waste battery recycling. This can play a crucial role in developing a circular economy through the recovery of critical raw materials (CRMs), as well as non-metallic components back to use. In recent years, the recycling technologies for LIBs entered in a new stage focused on the development of i) advanced pre-treatment processes to separate all the valuable battery components, and ii) more sustainable metallurgical approaches. Compared to the common recycling processes, Supercritical Fluid (SCF) technology is environmentally benign, chiefly if CO2 is used as the SCF (scCO2). This review aims at providing an overview on the current progresses and the open challenges of SCF technology for the treatment of End-of-Life LIBs. The fundamentals of SCF technology process are discussed, providing the reader a brief overview of principles, operation procedures and instrumentation. Thereafter, the main applications in the field of batteries recycling are reviewed, including electrolyte recovery and high-rate extraction of critical metals from the cathode. Finally, a focus is given on the huge innovation potential of scCO2 to separate and reuse the fluorinated binder from the electrode. At present, the binder is burnt in the common recycling processes, leading to hazardous fluorinated gas emissions.

The sodium-ion battery (Na-ion battery, NIB) is considered the most promising post-lithium energy storage technology, taking advantage of using the same manufacturing technology as Li-ion batteries (LIBs), while enabling the use of more abundant and economic, thus more sustainable, raw materials. Due to the inability of Na+ ions to be intercalated within the graphene-layered structure of graphite-based electrodes (the state of art anode material in LIBs), highly disordered and microporous carbons, known as hard carbons, are considered the anode material of choice for NIB technology. Biomass-derived biochar (BC) is one of the most relevant classes of hard carbons, exhibiting a good combination of sustainable fabrication, structural-morphological features and electrochemical performances. In this review, the main achievements on BC are rigorously reported from the production to the application into NIBs, with particular emphasis on the strategies to improve the electrochemical behaviour of BC by activating it and tailoring its chemical and structural properties. These strategies include selecting specific feedstocks, modulation of the pyrolysis temperature, pre- and post-production treatments, and materials engineering. The possible role of BC in sustainable NIBs development is also briefly discussed, together with some insights of its use in other post-Li energy storage systems and some concluding remarks and future direction of the research.

Lithium-ion cells encompassing LiPF6 as the lithium salt and high-voltage (LiNi0.5Mn1.5O4, LNMO) or high-capacity (LiNi0.8Mn0.1Co0.1O2, NMC811) cathode materials are prone to transition metal (TM) dissolution caused by HF, whose formation is catalyzed by H2O traces. TM ions can shuttle to the anodic compartment, increasing the cell degradation rate. Accordingly, specific self-healing strategies are helpful to develop scavengers able to eliminate HF and absorb TM ions so avoiding their shuttling. In this work, the fabrication and test of a bi-functional, autonomous scavenging agent made of Al2O3 particles decorated is reported with chitosan. The nanometric Al2O3 core is a trap for HF by chemical bonding. The chitosan coating is acid-sensitive, and the opening of such a capping layer is triggered in the presence of even small amounts of HF, leading to an efficient TM ion-trapping. In addition, chitosan is biocompatible, biodegradable, and abundant, which is relevant for design-for-recycling scopes. With approximate to 200 ppm of water in the electrolyte, 12 wt% of scavenger causes, after 200 cycles at 1C, an increase of capacity retention from 73% to 88% for LNMO, and, impressively, from 46% to 84% for NMC811. This autonomous self-healing mechanism is promising for application in next-generation smart cells without requiring any external sensing. Multi-functional scavenger made of Al2O3 nanoparticles decorated with chitosan is produced and tested in cathodes for LIBs. Al2O3 core is a trap for HF. The chitosan capping is acid-sensitive, and the opening of such a coating layer is triggered in the presence of HF, leading to efficient TM ion-trapping. This scavenging mechanism is promising for application in next-generation smart cells without external sensing. image

The rapid growth in demand for lithium-ion batteries (LIBs) is leading to increasing challenges in: (i) the management of end-of-life (EoL) systems of electric vehicles (EVs) and industrial applications with huge variety in chemistry and design; (ii) the supply of critical raw materials (CRMs), especially Lithium, Cobalt and Nickel, whose ores are known to be conflict resources, and currently under the spotlight in the recycling field. The above-mentioned challenges can be addressed by collecting and recycling spent LIBs through economically and environmentally sustainable processes and enabling the transition to a circular economy vision based on the use of secondary raw materials. These processes involve not only the metallurgic approaches to recover the critical metals, but also the pre-treatment approaches in LIBs recycling that are crucial to enhance the recovery efficiency of other valuable materials (e.g., graphite, fluorinated compounds, binders, electrolyte), and to reduce the energy consumption in the subsequent metallurgic processes. Here, some pre-treatment processes, from the disassembling, opening, and sorting to the component separation, collection, and recovery, are described for the EoL 18650-type commercial Li-ion batteries (4400 mAh) harvested from a laptop module. Additionally, a closed loop of eco-friendly recycling to fully recover the composite cathode (both cathode active material, CAM, and binder) is presented. In the case of CAM, two different processes were explored: (i) soft-solvometallurgy via green solvents based on deep eutectic solvents (DESs); (ii) direct recycling. The recovered materials were used to prepare a new composite cathode that was assembled in a new cell using the recovered separator and characterized to evaluate the effective feasibility of the whole recycling process.

The design of multifunctional separators can address crucial drawbacks of the lithium-metal batteries. Here, a novel Janus separator (JS) is developed with tunable properties to prevent internal short circuiting and improve the cathode/electrolyte interface. JS is a P(VdF-HFP) composite with LLZO facing lithium (Li) anode (Layer A) and N-CQDs contacting the NMC cathode. Layer A acts as Li-ion flux regulator to hinder dendrite propagation; Layer B plays multiple roles: i) promotion of better carrier migration, ii) protection from side reactions at the NMC cathode and iii) action as physical barrier against dendrite penetration. Galvanostatic cycling of Li/NMC cells with JS including 5 wt% CQDs demonstrated that JS was effective to avoid self-discharge and internal short-circuiting due to dendrite perforation, resulting in enhanced cell lifespan. Specific capacity >150 mAh g(-1) with capacity retention of 91 % was delivered over 130 cycles at 1C. This result contrasted with higher capacity loss (>25 %) and cell failure in case of P(VdF-HFP) and Single Layer A separators, respectively. Post-mortem SEM on JS confirmed that the introduced functionalities successfully intercept dendrites. ARC overheating tests on JS-based cells demonstrated a remarkably higher thermal resistance and lower severity of the exothermic phenomena compared to Celgard separators.

Lithium (Li) metal is the most attractive anode material for the next generation Li batteries. However, crucial open challenges still limit its applicability at large scale, such as the low coulombic efficiency, unstable electrodeposition, and dendrite propagation with severe safety concerns. One strategy to address these drawbacks is the rational design of innovative current collectors for the Li anode. Here, we report on a simple, low-cost, and easily scalable process based on Additive Manufacturing technology via extrusion 3D printing to produce Cu current collectors with different and tuneable patterned structures. The current collectors are characterized by means of X-ray diffractometry, electron microscopy, profilometry and galvanostatic cycling. We show that the three-dimensional network can significantly stabilize the electrodeposition of Li, thanks to an enhanced electroactive surface area that enables a better Li accommodation without uncontrollable dendrite growth. Contrary to the planar current collector, the Li anode supported by the 3D current collectors exhibits stable and low voltage hysteresis at different current densities and can run for at least 330 hours without short-circuiting. Moreover, the evaluation of Li@3DCu anode in a LiFePO4-based full cell by galvanostatic cycling reveals excellent rate performances, achieving specific capacity exceeding 100 mAh g(-1) at 1 C and coulombic efficiency higher than 99 %. These results show that the material extrusion 3D printing approach is a versatile strategy to develop new and safer anodes with a long lifespan and reduced amount of Li metal.

Abstract A successful strategy for improving the safety issues of new‐generation lithium‐ion batteries is to replace liquid electrolytes with solid or quasi‐solid membranes, a procedure that ensures adequate ionic conductions and are mechanical strengths.