Demand For Batteries Research Articles

Online optimal scheduling for battery swapping charging systems with partial delivery

Battery swapping–charging system (BSCS) is a promising operating paradigm to provide centering charging and battery swapping service for electric vehicles in transportation electrification. Facing real-time information on battery demand under the limited transporting trucks, flexible online optimization of battery delivery and transportation routing is essential for meeting practical requirements. This paper investigates the real-time scheduling problem in BSCS, considering the battery partial delivery, energy demand, delivery deadline, and vehicle routing. Considering the non-deterministic polynomia hardness of battery transportation, the offline BSCS is a time-consuming task and is unsuitable for the online setting. A Lagrangian relaxation-based Benders decomposition is proposed for parallel and real-time implementation, improving the scheduling efficiency. To tackle future information such as battery demands and delivery deadlines, by introducing the dummy copy, the offline algorithm is embedded within a rolling horizon framework to solve in real-time repeatedly. Finally, case studies using real road maps in Shanghai and Belgium have verified the validity of the proposed online framework and confirmed the necessity of considering partial delivery in enhancing the operation flexibility of BSCS. The computational efficiency of the proposed algorithm is studied under different scales of the road network, and the profit from partial delivery and online implementation are highlighted.

Fundamental Understanding of the Low Initial Coulombic Efficiency in SiOx Anode for Lithium-Ion Batteries: Mechanisms and Solutions.

To meet the ever-increasing demand for high-energy lithium-ion batteries (LIBs), it is imperative to develop next-generation anode materials. Compared to conventional carbon-based anodes, Si-based materials are promising due to their high theoretical capacity and reasonable cost. SiOx, as a Si-derivative anode candidate, is particularly encouraging for its durable cycling life, the practical application of which is, however, severely hindered by low initial Coulombic efficiency (ICE) that leads to continuous lithium consumption. What is worse, low ICE also easily triggers a terrible chain reaction causing bad cycling stability. To further develop SiOx anode, researchers have obtained in-depth understandings regarding its working/failing mechanisms so as to further propose effective remedies for low ICE mitigation. In this sense, herein recent studies investigating the possible causes that fundamentally result in low ICE of SiOx, based on which a variety of solutions addressing the low ICE issue are discussed and summarized, are timely summarized. This perspective provides valuable insights into the rational design of high ICE SiOx anodes and paves the way toward industrial application of SiOx as the next generation LIB anode.

A Systematic Review of Lithium Battery Defect Detection Techniques and Technologies

This systematic review aims to explore and synthesize the existing literature on defect detection methods in lithium batteries. With the increasing demand for reliable and efficient lithium batteries in various applications, ensuring their safety and performance through effective defect detection is critical. This review categorizes and evaluates different detection techniques, including electrochemical, non-destructive testing (NDT), electrical, acoustic emission, optical methods, and machine learning. The primary objective is to provide a comprehensive understanding of the current state of defect detection technologies, assess their effectiveness, and identify key challenges and future research directions. The review covers various defect types, including manufacturing, operational, and environmental defects, and discusses the methodologies used for defect detection, including their sensitivity, accuracy, speed, cost, and practicality. Additionally, the review highlights real-world applications, case studies, and the integration challenges of these technologies with Battery Management Systems (BMS). By examining these aspects, the review aims to offer valuable insights for researchers, manufacturers, and practitioners in the field of lithium battery technology. Key findings suggest that while significant advancements have been made, there remain substantial challenges, particularly in the areas of data acquisition, standardization, and integration with existing battery management systems. Future research should focus on improving the robustness, scalability, and cost-effectiveness of defect detection methods, as well as developing comprehensive regulatory frameworks to ensure the safe deployment of lithium batteries.

Designer Anions for Better Rechargeable Lithium Batteries and Beyond.

Non-aqueous electrolytes, generally consisting of metal salts and solvating media, are indispensable elements for building rechargeable batteries. As the major sources of ionic charges, the intrinsic characters of salt anions are of particular importance in determining the fundamental properties of bulk electrolyte, as well as the features of the resulting electrode-electrolyte interphases/interfaces. To cope with the increasing demand for better rechargeable batteries requested by emerging application domains, the structural design and modifications of salt anions are highly desired. Here, salt anions for lithium and other monovalent (e.g., sodium and potassium) and multivalent (e.g., magnesium, calcium, zinc, and aluminum) rechargeable batteries are outlined. Fundamental considerations on the design of salt anions are provided, particularly involving specific requirements imposed by different cell chemistries. Historical evolution and possible synthetic methodologies for metal salts with representative salt anions are reviewed. Recent advances in tailoring the anionic structures for rechargeable batteries are scrutinized, and due attention is paid to the paradigm shift from liquid to solid electrolytes, from intercalation to conversion/alloying-type electrodes, from lithium to other kinds of rechargeable batteries. The remaining challenges and key research directions in the development of robust salt anions are also discussed.

Life cycle assessment of lithium carbonate production: Comparing sedimentary deposits

Lithium sedimentary deposits which were once considered impractical to extract, have become increasingly attractive for exploiting and producing high-quality lithium compounds, due to the surge in demand for batteries and from other markets. However, potential environmental impacts are yet to be evaluated for this emerging lithium production route. Therefore, this paper presents a comparative Life Cycle Assessment study for three prominent and near-to-opening lithium clay projects globally: Sonora Mexico, Falchani Peru, and Thacker Pass USA. Specifically, this study used literature, statistical data, expert interviews, and technical reports to develop cradle-to-gate models covering the mining to refining processes. The results suggest that lithium carbonate production in the Thacker Pass project has higher impacts than the two other selected sedimentary projects. Additionally, the impact categories of the Sonora project are significantly influenced by the source of electricity. The sensitivity analysis highlights the pivotal role of a transition to clean energy sources for these emerging lithium production routes. Especially, the Thacker Pass project would benefit significantly from on-site sulfuric acid production and power generation to reduce the associated environmental impacts.

Impact of Li Ion Transport Properties on Reversibility of Li Metal Electrode in Glyme‐Based Electrolytes

AbstractThe demand for innovative batteries with high specific energy densities has increased. Li‐metal batteries employing Li‐metal anodes, regarded as the ultimate anodes with a high theoretical capacity, have been extensively studied over the past few decades. However, the poor reversibility and safety concerns regarding Li‐metal anodes remain unresolved. The importance of the electrode/electrolyte interface, especially the solid electrolyte interphase (SEI), for achieving reversibility of Li metal anodes has been extensively studied. Herein, we focused on the impact of the Li ion transport properties in oligoether (glyme)‐based electrolytes on the deposition/dissolution efficiency of Li metal anodes. Analysis of the low‐frequency impedance spectra of Li‐plated Cu/Li cells revealed that the diffusion resistance of Li ions (Rdiffusion) may be a dominant contributor to the internal resistance of the cells employing glyme‐based electrolytes. A higher Rdiffusion in poor‐mass‐transport electrolytes with a lower Li ion transference number resulted in larger polarization during Li deposition/dissolution, leading to more pronounced unfavorable side reactions and lower Coulombic efficiency. Rdiffusion rather than interfacial resistance affected the reversibility of the Li metal anode. Enhancing the Li ion mass transport ability of electrolytes is important for achieving highly reversible charge‐discharge performance of Li metal anodes at high current densities.

Electrospun Co-Ni mixed multiple oxidation states heterostructure for high-performance Li-ion battery

With the increasing prevalence of mobile electronic devices, electric vehicles, and other technological advancements, there is a growing demand for higher-capacity Lithium-ion batteries (LIBs). Metal-organic frameworks (MOFs) have been actively researched in recent years due to their numerous advantages. However, the irreversible collapse during lithium-ion interaction hampers MOFs’ electrochemical stability. This study employs a direct precipitation method to synthesize uniformly shaped MOF materials, followed by carbon coating using electrospinning techniques, and ultimately, derivatives of MOF materials are produced through annealing. Thanks to this innovative material design process, exceptional performance is observed in this material as a lithium-negative electrode. After 1000 cycles at a high current density of 1 A g−1, its reversible capacity stabilizes at 1318 mAh g−1. Moreover, this negative electrode material exhibits exceptional rate performance at various current densities. The Co3O4/NiO@NCNFs electrode demonstrates enhanced charge storage capacity due to the synergistic effects of diffusion and capacitance control processes. Additionally, this material exhibits characteristics of low impedance and high lithium-ion diffusion rate. This study presents a novel method for manufacturing lithium-ion battery negative electrode materials by integrating MOF materials with electrospinning technology.

Chemical-Free Recycling of Cathode Material and Aluminum Foil from Waste Lithium-Ion Batteries by Combining Plasma and Ultrasonic Technology.

With the rapid demand for lithium-ion batteries due to the widespread application of electric vehicles, a significant amount of battery electrode pieces requiring urgent treatment are generated during battery production and disposal. The strong bonding caused by the presence of binders makes it challenging to achieve thorough separation between the cathode active materials and Al foil, posing difficulties in efficient battery material recycling. To address this issue, a plasma-ultrasonically combined physical separation method is proposed in this study. This method utilizes plasma-generated excited-state radicals assisted by ultrasonic waves to separate active materials and current collectors. The results indicate that the binders are effectively decomposed under plasma treatment at 13.56 MHz, 100 W, and 10 min in an oxygen atmosphere, resulting in a separation efficiency of 96.8 wt % for the cathode materials. Characterization results demonstrate that the morphology, crystal structure, and chemical composition of the recycled cathode active materials remain unchanged, facilitating subsequent direct restoration and hydrometallurgical recycling. Simultaneously, the Al foil is also completely recycled for subsequent reuse. Compared with traditional methods of separating cathode active materials and aluminum foil, the method proposed in this study has significant economic and environmental potential. It can promote the recycling of battery materials and the development of sustainable transportation.

Possibility of defective monolayer graphene as potential anode material of metal-ion batteries

The necessitates exploration in the field of rechargeable metal ion batteries demands safe, cost-efficient, and face significant challenges in their development. Defect engineering may be helpful for the ion storage and diffusion in the battery anodes. In this paper, we use density functional theory to investigate the adsorption and diffusion behavior of Li, Mg, and Al atom on single vacancy (SV), Stone-Wales vacancy (SWV), double vacancy (DV) and quadruple vacancy (QV) defective monolayer graphene. It is evident that metal exhibits the strongest adsorption strengthen at the defect center. The DV and QV defective graphene shows the ideal diffusion energy barrier for three metals. Importantly, the QV structure exhibit maximum storage capacities of the 775 mAh/g for Li, 911 mAh/g for Mg, and 1543.4 mAh/g for Al respectively. Additionally, their open-circuit voltages are all in a very safe range. This study can support a strong basis for the experimental research for metal-ion battery anodes.

Innovative amorphous multiple anionic transition metal compound electrode for extreme environments (≤ −80 °C) battery operations

The demand for lithium-ion batteries (LIBs) that function reliably in extreme environments has driven research efforts towards optimizing electrolyte composition, solid electrolyte interphase formation, and electrode materials. In this study, we pioneer an approach that utilizes amorphous-structured multiple anionic transition metal compounds as anodes, strategically paired with a cyclopentyl methyl ether (CPME)-based electrolyte, known for facilitating efficient Li+ conduction at low-temperatures. The synergistic effect yields exceptional LIB performance over a wide range of operating temperatures, stemming from the unique iron hydroxyl selenide (Fe(OH)Se) anode with a layered structure, enhanced ion diffusion pathways, and reduced energy requirements for conversion reactions combined with the CPME-based electrolyte. Specifically, Li//Fe(OH)Se LIBs with the CPME-based electrolyte exhibits initial discharge capacities of 974.7 mA h g−1 (at 1.0 A g−1) at room temperature, 285.2 mA h g−1 (at 0.025 A g−1) at −80 °C, and 1066.9 mA h g−1 (at 0.2 A g−1) at 45 °C. Notably, even at the extreme low-temperature of −100 °C, these LIBs remain operable.

Effect of ball milling energy and carbon content on electrochemical properties of FeF3/acetylene black composites for high-capacity thermal battery

Recently, there has been an increasing demand for high-voltage thermal batteries. FeF3 has a high open-circuit voltage of 2.7 V and is gaining attention as a potential alternative. However, it involves the problem of a low electrical conductivity owing to the wide band gap (5.96 eV) and the generation of lithium fluoride (LiF), which is a discharge product in the conversion reaction. To address this issue, acetylene black with high conductivity is utilized to enhance the electrochemical activity of metal fluoride (FeF3). At present, FeF3/AB is produced by low- and high-collision-energy ball milling. These are mechanical milling methods that involve different collision energies. High-collision-energy ball milling has been demonstrated to degrade the electrochemical performance owing to crystal deformation. In contrast, low-collision-energy ball milling has demonstrated the potential for application in thermal batteries by minimizing crystal deformation and enhancing the electrical conductivity. In this study, the amount of added carbon was optimized to enhance the performance of thermal battery materials. Both low- and high-collision-energy ball-milling processes exhibited remarkable thermal stability when 5.0 wt% carbon was added. However, the high-collision-energy ball-milling process did not effectively enhance the thermal cell performance because the electrical conductivity did not increase significantly. Therefore, FeF3/5.0 wt% AB produced by low-collision-energy ball milling exhibited remarkable thermal stability and electrical conductivity. This indicates its potential for use in thermal batteries.

Selective Extraction of Lithium from Spent-NMC Battery Cathodes Using Sodium Hydroxide as a Leaching Agent at Elevated Temperatures

Introduction: The demand for lithium-ion batteries (LIBs) is rapidly increasing due to the growth of the electronics and electric vehicle industries. Even though the batteries are rechargeable, their storage capacity decreases, and they eventually end up being wasted. Recycling the spent LIBs is necessary to reduce the environmental impact and utilize the precious metals contained in the waste Methods: The present work focuses on the selective recovery of lithium from the cathodes of spent NMC batteries through the hydrometallurgical process using a sodium hydroxide solution. The leaching process was carried out in 2 M and 4 M NaOH concentrations for 120 minutes at high pressure and at temperatures of 398.15 K, 423.15 K, 448.15 K, and 473.15 K. Experimental results showed that 56.53% of lithium could be recovered with nearly 100% selectivity under the optimum leaching conditions of 473.15 K and 4 M NaOH. The release of lithium ions was due to a combination of sodium adsorption, ion exchange, and impregnation mechanisms. Result: Calculation results showed that the activation energy of the lithium leaching process was 2.1990×104 J/mol, the reaction was endothermic with enthalpy and entropy at standard conditions (298.15 K) of 4.8936×105 J/mol and 1.4421×103 J/mol/K, respectively. Conclusion: The present work also suggested that total lithium recovery can be increased through a series of leaching processes.

Comprehensive reviews on the potential applications of inorganic metal sulfide nanostructures in biological, environmental, healthcare, and energy generation and storage

Abstract The versatile nature of metal sulfide nanostructures has led to their meteoric rise in popularity. The compositions, morphologies, and sizes of these nanostructures may be tuned, giving them distinct features. Here we look at the many uses of metal sulfide nanostructures, with an emphasis on their possible benefits in the fields of biology, ecology, and energy storage. Because of their remarkable optical characteristics and high degree of biocompatibility, metal sulfide nanostructures have great potential in the biological fields of bioimaging, medication administration, and photothermal treatment. Additionally, because of their large surface area and adsorption capability, these nanostructures show outstanding performance in environmental remediation, which includes pollutant removal and wastewater treatment. Because of their great conductivity and electrochemical activity, metal sulfide nanostructures are also in great demand for energy storage applications such supercapacitors, hydrogen storage, and lithium-ion batteries. This review provides a comprehensive analysis of recent progress in synthesizing various metal sulfides with transition metal elements. Effective physiochemical and biological approaches are employed in their production to control the structures, dimensions, and compositions of these sulfides.

Progressive effect of dual-hybridization in friction stir welding by ultrasonic vibration and resistive heating for joining dissimilar material Al6063 aluminium alloy and C26000 copper alloy

In the world of disruptive technology, Al–Cu joints are quite in demand for electric vehicle batteries and other ion battery applications. Fusion welding is the less preferred method due to its many disadvantages; friction stir welding has the potential to become a sustainable process for producing a sound dissimilar Al–Cu joint. A study of multiple hybridization to the Friction Stir Welding (FSW)was made by utilizing two different energy sources of ultrasonic energy and electric current. The improvement is the property by different combination of the hybridization studied for utilizing the multiple hybridization technique to the FSW process for improving the weld efficacy and defects free weld even in case of dissimilar joints. Mechanical properties obtained by varying the process parameters have been studied and compared. Three process parameters have been selected including ultrasonic energy (10 KHz), electric current (75–125 Amps), rpm (400–600 rpm) and transverse tool rate (30–50 mm/min). A remarkable improvement in the mechanical property has been monitored by adding electric current to the UAFSW. Similar optimistic results in the improvement of the property have been found by adding Ultrasonic energy to RHFSW. The comparative study in the mechanical property had been presented to explain the improvement in the weld efficacy.

Microstructural Evolution and Mechanical Behavior of Pure Aluminum Ultra-Thin Strip under Roller Vibration

As the demand for lithium-ion batteries increases, higher quality requirements are being placed on pure aluminum ultra-thin strips, one of the main materials used in lithium-ion battery current collectors. Roller vibration during the rolling process of pure aluminum ultra-thin strips is unavoidable and significantly affects the quality of the strips. This paper uses 1A99 pure aluminum ultra-thin strips as raw materials and employs a controlled vibration method during the rolling process to obtain products under two conditions: stable rolling and vibrational rolling. The surface and cross-section of the aluminum strips were characterized using scanning electron microscopy (SEM), and the microstructure of the surface and cross-section was studied using electron backscatter diffraction (EBSD) technology. The results show that, during stable rolling, the surface quality of the aluminum strip is good without defects. Under vibration, obvious vibration marks appear on the surface of the aluminum strip, showing characteristics of peaks and troughs. With the increase in strain at the trough position, there is a transition from low-angle grain boundaries to high-angle grain boundaries, and the grain size is uneven at the peak and trough positions, with noticeable grain refinement at the troughs. At the same time, under the influence of vibration, the aluminum strip induces a different texture morphology from conventional rolling. Due to the different plastic strains at the peak and trough positions, a texture alternation phenomenon occurs at these positions. The tensile test results indicate that aluminum strips exhibit poor mechanical properties under roller vibration, with the reduction in mechanical performance primarily attributed to the uneven microstructure distribution caused by roller vibration.

“Acid + Oxidant” Treatment Enables Selective Extraction of Lithium from Spent NCM523 Positive Electrode

With the rapid development of new energy vehicles and energy storage industries, the demand for lithium-ion batteries has surged, and the number of spent LIBs has also increased. Therefore, a new method for lithium selective extraction from spent lithium-ion battery cathode materials is proposed, aiming at more efficient recovery of valuable metals. The acid + oxidant leaching system was proposed for spent ternary positive electrode materials, which can achieve the selective and efficient extraction of lithium. In this study, 0.1 mol L−1 H2SO4 and 0.2 mol L−1 (NH4)2S2O8 were used as leaching acid and oxidant. The leaching efficiencies of Li, Ni, Co, and Mn were 98.7, 30, 3.5, and 0.1%, respectively. The lithium solution was obtained by adjusting the pH of the solution. Thermodynamic and kinetic studies of the lithium leaching process revealed that the apparent activation energy of the lithium leaching process is 46 kJ mol−1 and the rate step is the chemical reaction process. The leaching residue can be used as a ternary precursor to prepare regenerated positive electrode materials by solid-phase sintering. Electrochemical tests of the regenerated material proved that the material has good electrochemical properties. The highest discharge capacity exceeds 150 mAh g−1 at 0.2 C, and the capacity retention rate after 100 cycles exceeds 90%. The proposed new method can extract lithium from the ternary material with high selectivity and high efficiency, reducing its loss in the lengthy process. Lithium replenishment of the delithiation material can also restore its activity and realize the comprehensive utilization of elements such as nickel, cobalt, and manganese. The method combines the lithium recovery process and the material preparation process, simplifying the process and saving costs, thus providing new ideas for future method development.

A thermal management design using phase change material in embedded finned shells for lithium-ion batteries

Phase change material (PCM) has recently been regarded as a promising thermal management means for lithium-ion (Li-ion) batteries. However, solid-liquid phase change of many current PCMs occurs in a narrow temperature range, and the cooling performance of their liquid phase is rather poor. To tackle these issues, this article presents a battery thermal management (BTM) design which injects PCM into an aluminum shell around each cell, and machines the shell inner surfaces into a row of straight rectangular fins immersed into the PCM and its outer surfaces into a plain-fin shape exposed in the air. In the mild thermal conditions, the finned shells of two adjacent cells can be embedded and passive PCM cooling is employed. Once the PCM completely melts, the shells will move apart and an airflow will be driven through the gap between them. The BTM design can also protect Li-ion batteries in a freezing environment, by taking advantage of PCM solidification when the finned shells return to their embedded configuration. A series of experiments were conducted to examine its effectiveness on two 50Ah lithium nickel cobalt manganese oxide (NCM) prismatic batteries, which were discharged at a capacity-rate of 2C and at room temperatures of T0=25∘C, 40∘C and −10∘C. It is shown that in the battery discharge at T0=25∘C, PCM in the embedded finned shells effectively reduced the average battery-surface temperature (T¯) and the maximum temperature difference (ΔTmax) by 21% and 36.7%, respectively, compared to bare batteries. At T0=40∘C, this BTM design successfully limited the growth of T¯ to 9.0∘C and led to ΔTmax no more than 1.5∘C. As to the low-temperature scenario, it maintained the batteries at temperatures above T0 for 55.2% longer than those without any BTM protections. Its cooling performance was also compared with that of the conventional liquid-cooling scheme using a bottom serpentine-channel cooling plate. All these results clearly demonstrate that the BTM design in this article can compensate for the deficiencies of conventional PCM-based BTM schemes. Regardless of whether the PCM phase change is available, it has well coped with different thermal management demands of Li-ion batteries.

Evolving cobalt cycle and urban mines in the EU, 1988–2020

Urban mines are vital for resource security and resilience, but the intricacies of their recycling processes are often overlooked. This study uses dynamic Material Flow Analysis to delve into the EU's cobalt cycle from 1988 to 2020, focusing on urban cobalt mining potential. We observed a significant shift in EU cobalt consumption patterns, with the demand for electric vehicle batteries surpassing that for superalloys, thereby positioning batteries as the primary cobalt consumers. Moreover, batteries increasingly dominate the cobalt in-use stock. The recycling process experiences substantial losses, especially in collection and pretreatment stages, reaching up to 87 %. Our findings indicates that urban cobalt mines could account for 57–66 % of the EU's total cobalt consumption, amounting to 166–193 kt in a high scenario. These insights emphasize the changing dynamics of the EU cobalt cycle and the importance of efficient urban cobalt mine management.

High-Voltage Spinel Cathode Materials: Navigating the Structural Evolution for Lithium-Ion Batteries.

High-voltage LiNi0.5Mn1.5O4 (LNMO) spinel oxides are highly promising cobalt-free cathode materials to cater to the surging demand for lithium-ion batteries (LIBs). However, commercial application of LNMOs is still challenging despite decades of research. To address the challenge, the understanding of their crystallography and structural evolutions during synthesis and electrochemical operation is critical. This review aims to illustrate and to update the fundamentals of crystallography, phase transition mechanisms, and electrochemical behaviors of LNMOs. First, the research history of LNMO and its development into a LIB cathode material is outlined. Then the structural basics of LNMOs including the classic and updated views of the crystal polymorphism, interconversion between the polymorphs, and structure-composition relationship is reviewed. Afterward, the phase transition mechanisms of LNMOs that connect structural and electrochemical properties are comprehensively discussed from fundamental thermodynamics to operando dynamics at intra- and inter-particle levels. In addition, phase evolutions during overlithiation as well as thermal-/electrochemical-driven phase transformations of LNMOs are also discussed. Finally, recommendations are offered for the further development of LNMOs as well as other complex materials to unlock their full potential for future sustainable and powerful batteries.

A review of direct recycling methods for spent lithium-ion batteries

The increasing demand for lithium-ion batteries (LIBs) in new energy storage systems and electric vehicles implies a surge in both the shipment and scrapping of LIBs. LIBs contain a lot of harmful substances, and improper disposal can cause severe environment damage. Developing efficient recycling technology has become the key to the sustainable growth of the LIBs industry. At present, the extraction of high-value materials from spent LIBs using pyrometallurgical and hydrometallurgical processes is most usual. However, they consume a lot of energy and lead to secondary environmental pollution, which is not consistent with the idea of creating a green circular economy. Direct recycling has been suggested as a possible alternative method of dealing with the spent LIBs under non-destructive conditions in the further. Compared with traditional metallurgical technologies, direct regeneration significantly reduces the consumption of energy and chemical reagents, and has a high selectivity for certain metal ions, which is environmentally friendly. However, direct cycling is still in its infancy with many scientific and technological barriers. In this review, we first consider the necessity of recycling spent LIBs, and then summarize the failure mechanisms of degraded cathode materials in order to choose a corresponding regeneration method. The direct cycling technologies, including hydrothermal, solid-state, eutectic medium and electrochemical regeneration are introduced separately from the perspective of the experimental process, operating parameters, regeneration principles, advantages, and effects. Furthermore, the current problems and potential future research on the direct cycling of spent LIBs are also discussed.