Renowned for its remarkable electrochemical performance, temperature stability, safety attributes, and long-lasting durability, the LiFePO4 battery has gained prominence in diverse applications, particularly within the electric vehicle sector. Despite not holding the top market position, approximately 69 % of global batteries comprise LiFePO4, raising concerns about a potential increase in discarded batteries. Present research predominantly concentrates on extracting valuable materials such as Co, Li, Ni, and Mn, frequently sidelining spent LiFePO4 batteries due to their perceived limited recoverable content compared to NMC and LCO batteries. However, LiFePO4 batteries removed from electric vehicles retain approximately 80 % of their initial capacity, with the cathode material sustaining a robust crystal structure. Here, direct recycling techniques employing a green reducing agent like ascorbic acid have shown promise in rectifying lithium vacancies and anti-sites in spent LiFePO4 through high power ultrasonic reactions. This work delves into exploring the influence of different lithium sources and Li (+) concentrations on the structure and electrochemical performance of regenerated LiFePO4. The direct regeneration of LiFePO4 showcases a favorable crystal structure that maintains stable phase transitions during charge and discharge processes. RLFP-0.2 M exhibits discharge specific capacity of 154.71 mAh center dot g(-1). It indicates RLFP-0.2 M maintains a discharge specific capacity of 132.89 mAh center dot g(-1) after 200 cycles at 1C current, retaining a remarkable capacity retention rate of 93.56 %. This study demonstrates that high-power ultrasonication is a universally applicable, low-energy, highly efficient, operationally simple, and environmentally friendly method for direct recycling of spent LiFePO4 batteries. Our research not only investigates the influence of various lithium sources and Li (+) concentration but also optimizes the recycling process for spent LiFePO4 batteries. Additionally, it provides an experimental foundation and reference for the recycling of other power batteries, contributing to achieving green direct recycling of various power batteries.

In various domains spanning materials synthesis, chemical catalysis, life sciences, and energy materials, in situ transmission electron microscopy (TEM) methods exert a profound influence. These methodologies enable the real-time observation and manipulation of gas-phase and liquid-phase reactions at the nanoscale, facilitating the exploration of pivotal reaction mechanisms. Fundamental research areas like crystal nucleation, growth, etching, and self-assembly have greatly benefited from these techniques. Additionally, their applications extend across diverse fields such as catalysis, batteries, bioimaging, and drug delivery kinetics. However, the intricate nature of 'soft matter' presents a challenge due to the unique molecular properties and dynamic behavior of these substances that remain insufficiently understood. Investigating soft matter within in situ liquid-phase TEM settings demands further exploration and advancement compared to other research domains. This research harnesses the potential of in situ liquid-phase TEM technology while integrating deep learning methodologies to comprehensively analyze the quantitative aspects of soft matter dynamics. This study centers on diverse phenomena, encompassing surfactant molecule nucleation, block copolymer behavior, confinement-driven self-assembly, and drying processes. Furthermore, deep learning techniques are employed to precisely analyze Ostwald ripening and digestive ripening dynamics. The outcomes of this study not only deepen the understanding of soft matter at its fundamental level but also serve as a pivotal foundation for developing innovative functional materials and cutting-edge devices.

Lithium iron phosphate batteries, known for their durability, safety, and cost-efficiency, have become essential in new energy applications. However, their widespread use has highlighted the urgency of battery recycling. Inadequate management could lead to resource waste and environmental harm. Traditional recycling methods, like hydrometallurgy and pyrometallurgy, are complex and energy-intensive, resulting in high costs. To address these challenges, this study introduces a novel low-temperature liquid-phase method for regenerating lithium iron phosphate positive electrode materials. By using N2H4·H2O as a reducing agent, missing Li+ ions are replenished, and anti-site defects are reduced through annealing. This process restores nearly all missing Li+ ions at 80 °C/6h. After high-temperature sintering at 700 °C/2h, the regenerated LiFePO4 matches commercial LiFePO4 in terms of anti-site defects and exhibits excellent performance with a 97 % capacity retention rate after 100 cycles at 1C. Compared to high-temperature techniques, this low-temperature liquid-phase method is simpler, safer, and more energy-efficient, offering a blueprint for reclaiming discarded LiFePO4 and similar materials.

The effective recycling of retired LiFePO4 batteries serves dual purposes: addressing the resource supply-demand contradiction and mitigating environmental pollution. However, the existing recycling methods for waste LiFePO4 batteries often entail high energy consumption, time consumption, complex procedures, or the use of substantial amounts of chemical raw materials, leading to increased recycling costs. Moreover, both methods generate toxic gases or discharge excessive pollutant-containing liquids during the recycling process, posing a risk of secondary pollution. Here, we introduce the application of ultrasound-assisted regeneration in waste LiFePO4 cathode material directly. Ultrasound waves generate localized high temperature, high pressure, and intense shock wave jets to repair the lithium vacancy defects and anti-site defects in the waste LiFePO4. Based on the experimental findings, the regeneration of LiFePO4 was achieved with impressive results. At an ultrasound power of 500 W and a duration of 50 min, the regenerated LiFePO4 displayed a discharge specific capacity of 135.1 mAh center dot g(-1) and an impressive capacity retention of 97 % after 100 cycles at a 1C (1C = 170 mA g(-1)) current density. This study presents a promising and environmentally friendly approach for recycling and regenerating retired LiFePO4 batteries.

Lithium batteries are emerging as key contenders for next-generation energy storage due to their high energy density, and promising advances in consumer electronics and electric vehicles. A critical component in lithium batteries is the separator, which not only facilitates ion transport between electrodes but also prevents dendrite formation that can lead to short-circuits which is a major barrier to widespread adoption. This review examines the evolution and current state of separators for lithium-ion and lithium-metal batteries, emphasizing their role in enhancing performance and safety. It addresses the failure mechanisms that can undermine separator effectiveness and highlights the importance of developing advanced materials to overcome these challenges. Future advancements in lithium battery technology are closely tied to innovations in separator design. By exploring recent advancements and emerging trends, this review aims to outline potential development paths for improving separator materials. It seeks to address key issues and propose novel approaches, ultimately contributing to the development of safer, more efficient, and commercially viable lithium metal batteries. (c) 2024 Elsevier Ltd. All rights are reserved, including those for text and data mining, AI training, and similar technologies.

Withthe increase in dependence on renewable energy sources, interestin energy storage systems has increased, particularly with solar cells,redox flow batteries, and lithium batteries. Multiple diagnostic techniqueshave been utilized to characterize various factors in relation tothe battery performance. Electrochemical tests were used to studythe energy density, capacity, cycle life, rate, and other relatedproperties. Furthermore, it is critical to correlate the informationcollected from the characterization of materials to its propertieswhile functioning for advanced batteries. In situ and operando electronmicroscopy methods are specifically designed to conduct such characterization,and analysis was found to be the best method to achieve that objective.However, the characterization information collected varies accordingto the types of electron microscopy techniques. Also, the use of complementaryanalytical techniques further provides a more comprehensive studyof these different characterizations, giving insights into the morphology-performancerelationship of battery materials and interfaces. Within this review,the focus is on in situ and operando electron microscopy characterizationof battery materials, including transmission electron microscopy (TEM),scanning electron microscopy (SEM), cryogenic transmission electronmicroscopy (Cryo-TEM), and three-dimensional (3D) electron tomography.This review aims to cover both advanced electron microscopy imagingtechniques and their applications in the characterization of batterymaterials involving cathode, anode, and separator and solid electrolyteinterphase (SEI). The review discusses a range of advanced electronmicroscopy techniques, including TEM, SEM, and atomic force microscopy,as well as associated analytical techniques such as energy-dispersiveX-ray spectroscopy and electron energy loss spectroscopy. The useof these techniques has led to significant advances in our understandingof battery materials, including the identification of new phases andstructures, the study of interface properties, and the characterizationof defects and degradation mechanisms. Future perspectives on theseadvanced electron microscopy techniques and opportunities are alsodiscussed. Overall, this review highlights the importance of electronmicroscopy in battery research and the potential for these techniquesto drive future advancements in the field.

In situ liquid phase transmission electron microscopy (TEM) and three-dimensional electron tomography are powerful tools for investigating the growth mechanism of MOFs and understanding the factors that influence their particle morphology. However, their combined application to the study of MOF etching dynamics is limited due to the challenges of the technique such as sample preparation, limited field of view, low electron density, and data analysis complexity. In this research, we present a study employing in situ liquid phase TEM to investigate the etching mechanism of colloidal zeolitic imidazolate framework (ZIF) nanoparticles. The etching process involves two distinct stages, resulting in the development of porous structures as well as partially and fully hollow morphologies. The etching process is induced by exposure to an acid solution, and both in situ and ex situ experiments demonstrate that the outer layer etches faster leading to overall volume shrinking (stage I) while the inner layer etches faster giving a hollow morphology (stage II), although both the outer layer and inner layer have been etched in the whole process. 3D electron tomography was used to quantify the properties of the hollow structures which show that the ZIF-67 crystal etching rate is larger than that of the ZIF-8 crystal at the same pH value. This study provides valuable insights into MOF particle morphology control and can lead to the development of novel MOF-based materials with tailored properties for various applications.

Si-based rechargeable lithium-ion batteries (LIBs) have generated interest as silicon has remarkably high theoretical specific capacity. It is projected that LIBs will meet the increasing need for extensive energy storage systems, electric vehicles, and portable electronics with high energy densities. However, the Si-based LIB has a substantial problem due to the volume cycle variations brought on by Si, which result in severe capacity loss. Making Si-based anodes-enabled high-performance LIBs that are easy to utilize requires an understanding of the fading mechanism. Due to its distinct advantage in morphological changes from microscale to nanoscale, even approaching atomic resolution, electron microscopy is one of the most popular methods. Based on operando electron microscopy characterization, the general comprehension of the fading mechanism and the morphology evolution of Si-based LIBs are debated in this review. The current advancements in compositional and structural interpretation for Si-based LIBs using advanced electron microscopy characterization methods are outlined. The future development trends in pertinent silicon materials characterization methods are also highlighted, along with numerous potential research avenues for Si-based LIBs design and characterization.