Unveiling the lithium deintercalation mechanisms in spent lithium-ion batteries via sulfation roasting.

Recovery of valuable metals from spent lithium-ion batteries (LIBs) is of great importance for resource sustainability and environmental protection. This study introduced pyrite ore (FeS2) as an alternative additive to achieve the selective recovery of Li2CO3 from spent LiCoO2 (LCO) batteries. The mechanism study revealed that the sulfation reaction followed two pathways. During the initial stage (550 °C-800 °C), the decomposition and oxidation of FeS2 and the subsequent gas-solid reaction between the resulting SO2 and layered LCO play crucial roles. The sulfation of lithium occurred prior to cobalt, resulting in the disruption of layered structure of LCO and the transformation into tetragonal spinel. In the second stage (over 800 °C), the dominated reactions were the decomposition of orthorhombic cobalt sulfate and its combination with rhombohedral Fe2O3 to form CoFe2O4. The deintercalation of Li from LCO by the substitution of Fe and conversion of Co(III)/Fe(II) into Co3O4/CoFe2O4 were further confirmed by density functional theory (DFT) calculation results. This fundamental understanding of the sulfation reaction facilitated the future development of lithium extraction methods that utilized additives to substantially reduce energy consumption.

Structural tuning of copper sulfide material for sodium-ion batteries.

In this work, single-crystal and twin-crystal copper sulfide materials are constructed in a regulatable and controlled manner. Twin boundaries are engineered into the copper sulphide material to significantly improve its electrochemical performance. The results demonstrate that structure tuning with twin crystals is an effective strategy for enhancing electrochemical reactions, and also sheds light on the design of electrode materials for sodium ion storage.

Echocardiographic parameters predicting spontaneous closure of ductus arteriosus in preterm infants.

Objective: To evaluate the value of echocardiographic parameters in predicting early spontaneous closure of ductus arteriosus in premature infants. Methods: 222 premature infants admitted to the neonatal ward of our hospital were selected, and patent ductus arteriosus was detected by echocardiography 48 h after birth. On the 7th day, whether the ductus arteriosus was closed naturally in this cohort was observed. The infants whose ductus arteriosus were not closed were identified as the PDA group (n = 109), and the other infants were included in the control group (n = 113). The echocardiographic parameters of the two groups of premature infants at 48 h after birth were single-factor statistically and Pearson correlation analyzed, and the parameters with statistically significant differences in single-factor analyzed were selected for multivariate logistic stepwise regression analysis. Results: The ductus arteriosus shunt velocity and the pressure difference between the descending aorta and the pulmonary artery (ΔPs) in the PDA group were lower than those in the control group (P < 0.05). The pulmonary artery pressure (PASP) in the PDA group was higher than that in the control group (P < 0.05). According to the multivariate logistic stepwise regression analysis, only the maximum shunt velocity of ductus arteriosus was correlated with early spontaneous closure of ductus arteriosus in 48 h first echocardiographic parameters (P = 0.049). The receiver operating characteristic (ROC) curve indicates the optimal critical point of echocardiographic ductus arteriosus shunt velocity in premature infants 48 h after birth was 1.165 m/s. Conclusion: Echocardiographic parameters are of great value in predicting the early spontaneous closure of ductus arteriosus in premature infants. In particular, the ductus arteriosus shunt velocity is correlated with the early spontaneous closure of ductus arteriosus.

Acid-free extraction of valuable metal elements from spent lithium-ion batteries using waste copperas.

A large amount of hazardous spent lithium-ion batteries (LIBs) is produced every year. Recovery of valuable metals from spent LIBs is significant to achieve environmental protection and alleviate resource shortages. In this study, a green and facile process for recovery of valuable metals from spent LIBs by waste copperas was proposed. The effects of heat treatment parameters on recovery efficiency of valuable metals and the redox mechanism were studied systematically through phase transformation behavior and valence transition. At low temperature (≤460 °C), copperas reacted with lithium on the outer layer of LIBs preferentially, but the reduction of transition metals was limited. As the temperature rose to 460-700 °C, the extraction efficiency of valuable metals was greatly enhanced due to the generation of SO2, and the gas-solid reaction proceeded much fast than the solid-solid reaction. In the final stage (≥700 °C), the main reactions were the thermal decomposition of soluble sulfates and the combination of decomposed oxides with Fe2O3 to form insoluble spinel. Under the optimum roasting conditions, i.e., at a copperas/LIBs mass ratio of 4.5, and a roasting temperature of 650 °C and roasting time of 120 min, the leaching efficiencies of Li, Ni, Co and Mn were 99.94%, 99.2%, 99.5% and 99.65%, respectively. The results showed that valuable metals can be selectively and efficiently extracted from the complex cathode materials by water leaching. This study used waste copperas as an aid to recover metals and provided an alternative technical route for green recycling of spent LIBs.

Folate-targeted perfluorohexane nanoparticles carrying bismuth sulfide for use in US/CT dual-mode imaging and synergistic high-intensity focused ultrasound ablation of cervical cancer.

The integration of multimodal contrast-enhanced diagnostic imaging techniques with noninvasive high-intensity focused ultrasound (HIFU) synergistic therapy could allow the real-time guidance, monitoring, and assessment of cancer therapeutic procedures and effects. Herein, we investigated the use of folate-targeted perfluorohexane nanoparticles carrying bismuth sulfide (Bi2S3) (FLBS-PFH-NPs) as a dual-modal contrast agent for ultrasound/computed tomography (US/CT) imaging and aimed to targeted increase the therapeutic efficiency of HIFU for cervical cancer treatment. FLBS-PFH-NPs were fabricated to investigate their potential as theranostic nanoplatforms. Their characteristics, phase-transformation properties, and cytotoxicities were also studied in this work. Sequential modifications with polyethylene glycol (PEG) endowed the FLBS-PFH-NPs with excellent stability and good biocompatibility. Moreover, compared with a non-folate-targeted group, the experimental group that received folate ligands had higher internalization efficiency and specificity. We sequentially investigated the effectiveness of these nanoparticles when used as dual-modal contrast agents in US and CT imaging in vitro and in vivo. The capsulated PFH could undergo a phase transition and form microbubbles upon ultrasonic irradiation, which enhanced the cavitation effects of HIFU in the targeted regions. Then, they were applied to in vitro bovine liver samples; the composite nanoparticles improved the efficiency of HIFU synergistic ablation. Our in vivo results also revealed that the coagulative necrosis volumes of tumors in the folate-targeted groups with HIFU ablation after FLBS-PFH-NP administration were significantly greater than those of the non-folate-targeted groups. Pathological and immunohistochemical examinations were systematically performed to further verify these results. In brief, FLBS-PFH-NPs may serve as a dual-modal contrast agent to enhance US/CT imaging and HIFU synergistic therapy. Novel nanosized multifunctional contrast agents would be of great value and could provide more comprehensive diagnostic information for more accurate and effective cancer therapy.