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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.

Autonomic self-healing (SH), namely, the ability to repair damages from mechanical stress spontaneously, is polarizing attention in the field of new-generation electrochemical devices. This property is highly attractive to enhance the durability of rechargeable Li-ion batteries (LIBs) or Na-ion batteries (SIBs), where high-performing anode active materials (silicon, phosphorus, etc.) are strongly affected by volume expansion and phase changes upon ion insertion. Here, we applied a SH strategy, based on the dynamic quadruple hydrogen bonding, to nanosized black phosphorus (BP) anodes for Na-ion cells. The goal is to overcome drastic capacity decay and short lifetime, resulting from mechanical damages induced by the volumetric expansion/contraction upon sodiation/desodiation. Specifically, we developed novel ureidopyrimidinone (UPy)-telechelic systems and related blends with poly(ethylene oxide) as novel and green binders alternative to the more conventional ones, such as polyacrylic acid and carboxymethylcellulose, which are typically used in SIBs. BP anodes show impressively improved (more than 6 times) capacity retention when employing the new SH polymeric blend. In particular, the SH electrode still works at a current density higher than 3.5 A g-1, whereas the standard BP electrode exhibits very poor performances already at current densities lower than 0.5 A g-1. This is the result of better adhesion, buffering properties, and spontaneous damage reparation.

High-entropy oxides based on transition metals, such as Mg0.2Co0.2Ni0.2Cu0.2Zn0.2O (TM-HEO), have recently drawn special attention as potential anodes in lithium-ion batteries due to high specific capacity and cycling reversibility. However, the lithiation/delithiation mechanism of such systems is still controversial and not clearly addressed. Here, we report on an operando XAS investigation into TM-HEO-based anodes for lithium-ion cells during the first lithiation/delithiation cycle. This material showed a high specific capacity exceeding 600 mAh g-1 at 0.1 C and Coulombic efficiency very close to unity. The combination of functional and advanced spectroscopic studies revealed complex charging mechanisms, developing through the reduction of transition-metal (TM) cations, which triggers the conversion reaction below 1.0 V. The conversion is irreversible and incomplete, leading to the final collapse of the HEO rock-salt structure. Other redox processes are therefore discussed and called to account for the observed cycling behavior of the TM-HEO-based anode. Despite the irreversible phenomena, the HEO cubic structure remains intact for ∼60% of lithiation capacity, so proving the beneficial role of the configuration entropy in enhancing the stability of the HEO rock-salt structure during the redox phenomena.

The ever-growing demand for Li-ion batteries requires high-capacity electrode materials that should also be environmentally benign, Co-free, secure and durable, to achieve an optimal compromise between sustainability and functional performances. Spinel LiMn2O4 (LMO) is a state-of-the-art material, which, in principle, could satisfy such requirements. However, an undesired cubic-tetragonal phase transition favors Jahn-Teller (J-T) spinel distortion, leading to severe capacity reduction upon cycling below 3 V. Here, we propose a dual-doping strategy for LMO, based on the partial substitution of Mn(III) with Fe(III) and Ti(IV) to design new active materials for high-capacity cathodes, namely LiFexMn2-x-yTiyO4 (LFMT), with Li/Mn ratio ranging between 1 and 1.7. The substitution of Mn with Fe and Ti suppresses the J-T distortion, which is often still evident in the case of Ti-doped LMO. This allows cycling in a wider voltage range (4.8-1.5 V), thus resulting in higher capacity and significantly improved stability. The lithiation mechanisms were investigated by combining ex-situ X-ray diffraction (XRD) and X-ray absorption spectroscopy (XAS analyses). It demonstrated that the only redox-active metal is Mn, while Fe and Ti are electrochemically inactive. The extensive electrochemical lithiation/delithiation of the LFMT compositions brought to unprecedented results, which give evidence of stabilizing cation disorder through the formation of Mn-rich and Mn-poor domains, which leades to two spinel phases with different Mn:Ti ratios. These insights into the lithiation mechanism pave the way for a better understanding of the doping chemistry and electrochemistry of Mn-based spinels as cathode materials for Li-ion batteries.

Harvesting systems capable of transforming mechanical vibration into electrical energy have attracted considerable interest with particular focus on electroactive polymers. In this work, a composite material consisting of a polyurethane matrix filled with a high-k ceramic nanofiller (CaCu3 Ti4O12) is fabricated by doctor blade coating. Single strips, with sputtered electrodes, are electrically connected in parallel increasing electrical capacitance. The required bias voltage is provided by two alternative solutions, a rechargeable battery or a custom electret made by corona charging.

An experimental method exploiting the capacitive response of most materials is here revised. The procedure called the “Voltage Ramp Method” (VRM) is based on applying proper voltage ramp cycles over time and measuring electrical current intensity flowing through the material sample. In the case of an ideal capacitor, a current plateau should be easily measured, and the capacitance value precisely determined. However, most media, e.g., semiconductors and insulating polymers, show dielectric absorption and hence electric leakage effects. Therefore, the VRM method allows simultaneous determination of their equivalent capacitance and resistance. Some case studies are discussed as concerning the application of VRM to both standard and actual media. A figure of merit of the method is the percentage difference between 2.5% and 1.5% with respect to the nominal values of a commercial capacitor and resistor, respectively. The simulation modeling of the material electrical response is compared to the experimental data also on polymer nanocomposites suitable for energy harvesting.

The transition to a circular economy vision must handle the increasing request of metals required to satisfy the battery industry; this can be obtained by recycling and feeding back secondary raw materials recovered through proper waste management. Here a novel and green proof-of-concept is proposed, based on deep eutectic solvents (DES) to fully and easily recover valuable metals from various cathode active materials, including LiMn 2 O 4 LiNi 0.5 Mn 1.5 O 4 and LiNi 0.8 Co 0.2 O 2 . DES composed of choline chloride and lactic acid can leach Li, Mn, Co and Ni, achieving efficiency of 100% under much milder conditions with respect to the previous literature. For the first time, to our best knowledge, a two-step approach is reported in the case of LiNi 0.8 Co 0.2 O 2 for selective recovery of Li, Co and Ni with high yield and purity. Furthermore, other cathode components, namely aluminium current collector and binder, were found to be not dissolved by the proposed DES, so making it possible for a simple separation from the active material. Finally, our strategy is designed to easily regenerate and reuse the leaching solvents for more than one extraction, thus further boosting the process's sustainability.

The cellular uptake of nanoparticles (NPs) represents a critical step in nanomedicine and a crucial point for understanding the interaction of nanomaterials with biological systems. No specific mechanism of uptake has been identified so far, as the NPs are generally incorporated by the cells through one of the few well-known endocytotic mechanisms. Here, an alternative internalization route mediated by microvilli adhesion is demonstrated. This microvillus-mediated adhesion (MMA) has been observed using ceria and magnetite NPs with a dimension of

LIBs present various critical raw materials (CRMs) (eg Li, Mn, Co, Ni, graphite), not present as massive and primary resources in Europe. The common recovery methods for the extraction of Co, Li, Ni metals are thermal/chemical methods like pyro and hydrometallurgical approaches. They are based on the metal leaching by solvent, supercritical fluid-extraction or chemical precipitation, with the use of strong acids and reducing agents to improve the metal dissolution. However, these processes are highly energy-consuming, require harsh conditions and produce toxic materials. In addition, they do not lead to easily recoverable elements [1]. In our work we are study a green, cheap and safe approach of extraction by using a new type of organic solvents as lixiviant, the Deep Eutectic Solvents (DES). DESs are obtained by simply mixing two safe components (cheap, renewable, and biodegradable), which are capable of forming a eutectic mixture, in our case we combine the acid lactic:choline chloride. We decide to focus the recovery of Li, Ni and Co in a LNC cathode (LiNi0.8Co0.2O2) and the use of the obtained precursor for the realization of a second life cathodes.

Is It Possible to Obtain Solvent-Free, Li

Is It Possible to Obtain Solvent-Free, Li+ -Conducting Solid Electrolytes Based on Pure PVdF? Comment on "Self-Suppression of Lithium Dendrite in All-Solid-State Lithium Metal Batteries with Poly(vinylidene difluoride)-Based Solid Electrolytes".