Two-Dimensional Transition Metal Phosphides As Cathode Additive in Robust Lithium-Sulfur Batteries.

The development of advanced cathode materials able to promote the sluggish redox kinetics of polysulfides is crucial to bringing lithium-sulfur batteries to the market. Herein, two electrode materials: namely, Zr2PS2 and Zr2PTe2, are identified through screening several hundred thousand compositions in the Inorganic Crystal Structure Database. First-principles calculations are performed on these two materials. These structures are similar to that of the classical MXenes. Concurrently, calculations show that Zr2PS2 and Zr2PTe2 possess high electrical conductivity, promote Li ion diffusion, and have excellent electrocatalytic activity for the Li-S reaction and particularly for the Li2S decomposition. Besides, the mechanisms behind the excellent predicted performance of Zr2PS2 and Zr2PTe2 are elucidated through electron localization function, charge density difference, and localized orbital locator. This work not only identifies two candidate sulfur cathode additives but may also serve as a reference for the identification of additional electrode materials in new generations of batteries, particularly in sulfur cathodes.

Air-Stable High-Entropy Layered Oxide Cathode with Enhanced Cycling Stability for Sodium-Ion Batteries.

O3-type layered oxides have been extensively studied as cathode materials for sodium-ion batteries due to their high reversible capacity and high initial sodium content, but they suffer from complex phase transitions and an unstable structure during sodium intercalation/deintercalation. Herein, we synthesize a high-entropy O3-type layered transition metal oxide, NaNi0.3Cu0.05Fe0.1Mn0.3Mg0.05Ti0.2O2 (NCFMMT), by simultaneously doping Cu, Mg, and Ti into its transition metal layers, which greatly increase structural entropy, thereby reducing formation energy and enhancing structural stability. The high-entropy NCFMMT cathode exhibits significantly improved cycling stability (capacity retention of 81.4% at 1C after 250 cycles and 86.8% at 5C after 500 cycles) compared to pristine NaNi0.3Fe0.4Mn0.3O2 (71% after 100 cycles at 1C), as well as remarkable air stability. Finally, the NCFMMT//hard carbon full-cell batteries deliver a high initial capacity of 103 mAh g-1 at 1C, with 83.8 mAh g-1 maintained after 300 cycles (capacity retention of 81.4%).

High throughput selection of organic cathode materials.

Efficient and affordable batteries require the design of novel organic electrode materials to overcome the drawbacks of the traditionally used inorganic materials, and the computational screening of potential candidates is a very efficient way to identify prospective solutions and minimize experimental testing. Here we present a DFT high-throughput computational screening where 86 million molecules contained in the PUBCHEM database have been analyzed and classified according to their estimated electrochemical features. The 5445 top-performing candidates were identified, and among them, 2306 are expected to have a one-electron reduction potential higher than 4 V versus (Li/Li+ ). Analogously, one-electron energy densities higher than 800 Whkg-1 have been predicted for 626 molecules. Explicit calculations performed for certain materials show that at least 69 candidates with a two-electron energy density higher than 1300 Whkg-1 . Successful molecules were sorted into several families, some of them already commonly used electrode materials, and others still experimentally untested. Most of them are small systems containing conjugated CO, NN, or NC functional groups. Our selected molecules form a valuable starting point for experimentalists exploring new materials for organic electrodes.

Recent Advances in Catalyst Design and Performance Optimization of Nanostructured Cathode Materials in Zinc-Air Batteries.

This review focuses on the advanced design and optimization of nanostructured zinc-air batteries (ZABs), with the aim of boosting their energy storage and conversion capabilities. The findings show that ZABs favor porous nanostructures owing to their large surface area, and this enhances the battery capacity, catalytic activity, and life cycle. In addition, the nanomaterials improve the electrical conductivity, ion transport, and overall battery stability, which crucially reduces dendrite growth on the zinc anodes and improves cycle life and energy efficiency. To obtain a superior performance, the importance of controlling the operational conditions and using custom nanostructural designs, optimal electrode materials, and carefully adjusted electrolytes is highlighted. In conclusion, porous nanostructures and nanoscale materials significantly boost the energy density, longevity, and efficiency of Zn-air batteries. It is suggested that future research should focus on the fundamental design principles of these materials to further enhance the battery performance and drive sustainable energy solutions.

Tetrahedral Occupied V Ions Enabling Reversible Three-Electron Redox of Cr3+ /Cr6+ in Layered Cathode Materials for Potassium-Ion Batteries.

Reversible three-electron redox of Cr3+ /Cr6+ in layered cathode materials for rechargeable batteries is very attractive in layered cathode materials, which leads to high capacity and energy density for rechargeable batteries. However, the poor reversibility and Cr-ion migration make it very challenging. In this work, by introducing V ions into tetrahedral sites of layer-structured NaCrO2 , reversible three-electron redox of Cr3+ /Cr6+ is realized successfully in NaCr0.92 V0.05 O2 (NCV05) cathode for potassium-ion batteries with a cut-off voltage of 4.0 V. V ions can weaken the attraction of Cr to electrons, leading to enhanced valence change of Cr ions. On the other hand, V in tetrahedral sites can facilitate the reversible migration of Cr between octahedral and tetrahedral sites via coulombic repulsion to realize the reversible redox between Cr3+ and Cr6+ during charge and discharge processes. In addition, V ions can inhibit the phase transition from O3 phase to O'3 phase during the charge process by adjusting the crystal lattices. As a result, the NaCr0.92 V0.05 O2 cathode exhibits a high reversible capacity of 130 mAh g-1 with promising cycle stability and rate capability. The strategy opens new opportunity for developing high-capacity cathode materials for potassium-ion batteries.

Chemical Cross-linked Electrode-Electrolyte Interface Boosting the Structural Integrity of High Nickel Cathode Materials.

High nickel cathode material LiNixCoyMn1-x-yO2 (NCM) (x ≥ 0.6) has represented the most critical material in virtue of outstanding specific capacity and low self-discharge. However, the high surface alkalinity and detrimental interfacial stability lead to the parasitic reaction and a series of phase deterioration. Herein, in situ cross-linking binder molecular chains with a 3D network structure to construct a stable and robust electrode-electrolyte interface, which can maintain the structural integrity and restrain side reactions is designed. Simultaneously, the cross-linked polymer can form stable hydrogen bonds with the pristine binder, greatly enhancing the bonding property. More importantly, the functional groups contained in the cross-linked co-polymers can chemically anchor transition metals, effectively preventing the dissolution of transition metals. Theoretical calculations confirm the feasibility and advancement of the anchoring mechanism, driving excellent structural stability and inhibition of the NiO impurity phase. This work provides a practical strategy to realize the high stability of cathode materials.

Exploring the Enhanced Zinc Storage Performance of α-MnSe Polyhedral Microspheres and H+/Zn2+ Co-Insertion Mechanism.

The newly emerged Mn-based selenides as cathodes for aqueous Zn-ion batteries (ZIBs) have drawn researchers' interest because of their lower electronegativity and better electronic conductivity compared with the corresponding Mn-based oxides. Nevertheless, the energy storage mechanism of Mn-based selenides still needs to be further clarified. Herein, the MnSe/Se and MnSe polyhedral microspheres are reported as cathodes for ZIBs, and the MnSe cathode achieves significantly enhanced specific capacity, rate performance, and cycling stability. In-depth kinetic analysis confirms that the MnSe cathode presents better kinetic behavior and density functional theory (DFT) calculations verify the fast diffusion kinetics of the MnSe cathode. More importantly, systematic ex situ characterizations reveal that the microstructured MnSe can exist stably during the charge-discharge process and store energy with H+/Zn2+ co-insertion mechanism, which is greatly different from the phase transformation of the nanostructured α-MnSe reported in the literature. Additionally, it is verified that the different types of separators exhibit remarkably different zinc storage performance of the MnSe cathode. This study not only offers a good guidance for developing high-performance ZIBs Mn-based cathode materials and explores the effect of separators on the zinc storage performance, but also provides new insights into the energy storage mechanism of the MnSe cathode.

Heterostructure Engineering for Aluminum-Ion Batteries: Mechanism, Challenge, and Perspective.

Benefiting from high volumetric capacity, environmental friendliness, and high safety, aluminum-ion batteries (AIBs) are considered to be promising battery system among emerging electrochemical energy storage technologies. As an important component of AIBs, the cathode material is crucial to decide the energy density and cycle life of AIBs. However, single-component cathode materials are unable to achieve a balance between cycling stability and rate performance. In recent years, research on heterostructure cathode materials has gained significant attention in AIBs. By harnessing the synergistic effects of heterostructure, the shortcomings of individual materials can be overcome, contributing to improved conductivity and structural stability. This review offers a detailed insight into the Al-storage mechanism of heterostructure cathodes, and provides an overview of the current research progresses on heterostructure cathode materials for AIBs. Starting from the relationship between the microstructure and electrochemical performance of heterostructure materials, the different structure design strategies are elaborated. Besides, the challenges faced by heterostructure are summarized, and their potential impact on the future of the energy storage industry is anticipated. This review provides the guidelines for the future research of heterostructure as cathode materials for AIBs.

Crown Ether Electrolyte Additive Enables High-Rate and Stable Polyviologen Cathode Material for Chloride Ion Batteries.

A variety of inorganic and inorganic cathode materials for chloride ion storage are reported. However, their application in chloride ion batteries (CIB) is hindered by poor rate capability and cycling stability. Herein, an organic poly(butyl viologen dichloride) (PBVCl2) cathode material with significantly enhanced rate and cycling performance in the CIB is achieved using a crown ether (18-Crown-6) additive in the tributylmethylammonium chloride-based electrolyte. The as-prepared PBVCl2 cathodes exhibit impressive capacity increases from 149.4 to 179.1 mAh g-1 at 0.1 C and from 57.8 to 111.9 mAh g-1 at 10 C, demonstrating the best rate performance with the highest energy density among those of various reported cathodes for CIBs. This impressive performance improvement is a result of the great boosts in charge transfer, ion transport, and interface stability of the battery by the use of 18-Crown-6, which also contributes to a more than twofold increase in capacity retention after 120 cycles. The electrode reaction mechanism of the CIB based on highly reversible chloride ion transfer is revealed by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy.

Advances in Aqueous Zinc Ion Batteries based on Conversion Mechanism: Challenges, Strategies, and Prospects.

Recently, aqueous zinc-ion batteries with conversion mechanisms have received wide attention in energy storage systems on account of excellent specific capacity, high power density, and energy density. Unfortunately, some characteristics of cathode material, zinc anode, and electrolyte still limit the development of aqueous zinc-ion batteries possessing conversion mechanism. Consequently, this paper provides a detailed summary of the development for numerous aqueous zinc-based batteries: zinc-sulfur (Zn-S) batteries, zinc-selenium (Zn-Se) batteries, zinc-tellurium (Zn-Te) batteries, zinc-iodine (Zn-I2) batteries, and zinc-bromine (Zn-Br2) batteries. Meanwhile, the reaction conversion mechanism of zinc-based batteries with conversion mechanism and the research progress in the investigation of composite cathode, zinc anode materials, and selection of electrolytes are systematically introduced. Finally, this review comprehensively describes the prospects and outlook of aqueous zinc-ion batteries with conversion mechanism, aiming to promote the rapid development of aqueous zinc-based batteries.

A Novel 4-Fluorophenyl Isocyanate Additive Constructing Solid Cathodes-Electrolyte Interface for High-Performance Lithium-Ion Batteries.

Building a stable cathode-electrolyte interface (CEI) is crucial for achieving high-performance layered metal oxide cathode materials LiNixCoyMn1-x-yO2 (NCM). In this work, a novel 4-fluorobenzene isocyanate (4-FBC) electrolyte additive that contains isocyanate and benzene ring functional groups is proposed, which can form robust and homogeneous N-rich and benzene ring skeleton CEI film on the cathode surface, leading to significant improvement in the electrochemical performance of lithium-ion batteries. Taking LiNi0.5Co0.2Mn0.3O2 (NCM523) as an example, the NCM523/SiO@Graphite pouch full cells with electrolytes containing a mass fraction of 1% 4-FBC additives demonstrate improved capacity retention after 200 cycles, retaining capacity retention rates of 81.3%, which is much higher than that of 39.1% without additive. The improvement can be ascribed to the mitigation of electrolyte decomposition and inhibition of transition metal ions the dissolution from the cathode material due to the stable CEI film. Moreover, the electrochemical performance enhancement can also be achieved in high voltage and Ni-rich cathode materials, indicating the universality and effectiveness of this strategy for the practical applications of high energy density lithium-ion batteries.

Aqueous Multivalent Metal-ion Batteries: Toward 3D-printed Architectures.

Energy storage has become increasingly crucial, necessitating alternatives to lithium-ion batteries due to critical supply constraints. Aqueous multivalent metal-ion batteries (AMVIBs) offer significant potential for large-scale energy storage, leveraging the high abundance and environmentally benign nature of elements like zinc, magnesium, calcium, and aluminum in the Earth's crust. However, the slow ion diffusion kinetics and stability issues of cathode materials pose significant technical challenges, raising concerns about the future viability of AMVIB technologies. Recent research has focused on nanoengineering cathodes to address these issues, but practical implementation is limited by low mass-loading. Therefore, developing effective engineering strategies for cathode materials is essential. This review introduces the 3D printing-enabled structural design of cathodes as a transformative strategy for advancing AMVIBs. It begins by summarizing recent developments and common challenges in cathode materials for AMVIBs and then illustrates various 3D-printed cathode structural designs aimed at overcoming the limitations of conventional cathode materials, highlighting pioneering work in this field. Finally, the review discusses the necessary technological advancements in 3D printing processes to further develop advanced 3D-printed AMVIBs. The reader will receive new fresh perspective on multivalent metal-ion batteries and the potential of additive technologies in this field.

Amorphous Cobalt Polyselenides with Hyperbranched Polymer Additive as High-Capacity Magnesium Storage Cathode Materials Through Cationic and Anionic Co-Redox Mechanism.

Rechargeable magnesium batteries (RMBs) are a promising energy-storage technology with low cost and high reliability, while the lack of high-performance cathodes is impeding the development. Herein, a series of amorphous cobalt polyselenides (CoSex, x>2) is synthesized with the assistance of organic amino-terminal hyperbranched polymer (AHP) additive and investigated as cathodes for RMBs. The coordination of cobalt cations with the amino groups of AHP leads to the formation of amorphous CoSex rather than crystalline CoSe2. The amorphous structure is favorable for magnesium-storage reaction kinetics, and the polyselenide anions provide extra capacities besides the redox of cobalt cations. Moreover, the organic AHP molecules retained in CoSex-AHP provide an elastic matrix to accommodate the volume change of conversion reaction. With a moderate x value (2.73) and appropriate AHP content (11.58%), CoSe2.7-AHP achieves a balance between capacity and cycling stability. Amorphous CoSe2.7-AHP provides high capacities of 246.6 and 94 mAh g‒1, respectively, at 50 and 2000 A g‒1, as well as a capacity retention rate of 68.5% after 300 cycles. The mechanism study demonstrates CoSex-AHP undergoes reversible redox of Co2+/3+↔Co0 and Sen 2‒↔Se2‒. The present study demonstrates amorphous polyselenides with cationic-anionic redox activities is as a feasible strategy to construct high-capacity cathode materials for RMBs.

Novel NASICON-Type Na-V-Mn-Ni-Containing Cathodes for High-Rate and Long-Life SIBs.

Partial substitution of V by other transition metals in Na3 V2 (PO4 )3 (NVP) can improve the electrochemical performance of NVP as a cathode for sodium-ion batteries (SIBs). Herein, phosphate Na-V-Mn-Ni-containing composites based on NASICON (Natrium Super Ionic Conductor)-type structure have been fabricated by sol-gel method. The synchrotron-based X-ray study, X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) studies show that manganese/nickel combinations successfully substitute the vanadium in its site within certain limits. Among the received samples, composite based on Na3.83 V1.17 Mn0.58 Ni0.25 (PO4 )3 (VMN-0.5, 108.1 mAh g-1 at 0.2 C) shows the highest electrochemical ability. The cyclic voltammetry, galvanostatic intermittent titration technique, in situ XRD, ex situ XPS, and bond valence site energy calculations exhibit the kinetic properties and the sodium storage mechanism of VMN-0.5. Moreover, VMN-0.5 electrode also exhibits excellent electrochemical performance in quasi-solid-state sodium metal batteries with PVDF-HFP quasi-solid electrolyte membranes. The presented work analyzes the advantages of VMN-0.5 and the nature of the substituted metal in relation to the electrochemical properties of the NASICON-type structure, which will facilitate further commercialization of SIBs.

Activating the MnS0.5Se0.5 Microspheres as High-Performance Cathode Materials for Aqueous Zinc-Ion Batteries: Insight into In Situ Electrooxidation Behavior and Energy Storage Mechanisms.

Manganese-based materials are regarded as the most prospective cathode materials because of their high natural abundance, low toxicity, and high specific capacity. Nevertheless, the low conductivity, poor cycling performance, and controversial energy storage mechanisms hinder their practical application. Here, the MnS0.5Se0.5 microspheres are synthesized by a two-step hydrothermal approach and employed as cathode materials for aqueous zinc-ion batteries (AZIBs) for the first time. Interestingly, in-depth ex situ tests and electrochemical kinetic analyses reveal that MnS0.5Se0.5 is first irreversibly converted into low-crystallinity ZnMnO3 and MnOx by in situ electrooxidation (MnS0.5Se0.5-EOP) during the first charging process, and then a reversible co-insertion/extraction of H+/Zn2+ occurs in the as-obtained MnS0.5Se0.5-EOP electrode during the subsequent discharging and charging processes. Benefiting from the increased surface area, shortened ion transport path, and stable lamellar microsphere structure, the MnS0.5Se0.5-EOP electrodes deliver high reversible capacity (272.8 mAh g-1 at 0.1 A g-1), excellent rate capability (91.8 mAh g-1 at 2 A g-1), and satisfactory cyclic stability (82.1% capacity retention after 500 cycles at 1 A g-1). This study not only provides a powerful impetus for developing new types of manganese-based chalcogenides, but also puts forward a novel perspective for exploring the intrinsic mechanisms of in situ electrooxidation behavior.

Enabling High-Performance Layered Li-Rich Oxide Cathodes by Regulating the Formation of Integrated Cation-Disordered Domains.

Layered Li-rich oxide cathode materials are capable of offering high energy density due to their cumulative cationic and anionic redox mechanism during (de)lithiation process. However, the structural instability of the layered Li-rich oxide cathode materials, especially in the deeply delitiated state, results in severe capacity and voltage degradation. Considering the minimal isotropic structural evolution of disordered rock salt oxide cathode during cycling, cation-disordered nano-domains have been controllably introduced into layered Li-rich oxides by co-doping of d0-TM and alkali ions. Combining electrochemical and synchrotron-based advanced characterizations, the incorporation of the phase-compatible cation-disordered domains can not only hinder the oxygen framework collapse along the c axis of layered Li-rich cathode under high operation voltage but also promote the Mn and anionic activities as well as Li+ (de)intercalation kinetics, leading to remarkable improvement in rate capability and mitigation of capacity and voltage decay. With this unique layered/rocksalt intergrown structure, the intergrown cathode yields an ultrahigh capacity of 288.4 mAh g-1 at 0.1 C, and outstanding capacity retention of ≈90.0% with obviously suppressed voltage decay after 100 cycles at 0.5, 1, and 2 C rate. This work provides a new direction toward advanced cathode materials for next-generation Li-ion batteries.

2D Conductive Metal-Organic Frameworks Based on Tetraoxa[8]circulenes as Promising Cathode for Aqueous Zinc Ion Batteries.

Aqueous zinc-ion batteries (ZIBs) are the new generation electrochemical energy storage systems. Recently, two-dimensional conductive metal-organic frameworks (2D c-MOFs) are attractive to serve as cathode materials of ZIBs due to their compositional diversity, abundant active sites, and excellent conductivity. Despite the growing interest in 2D c-MOFs, their application prospects are still to be explored. Herein, a tetraoxa[8]circulene (TOC) derivative with unique electronic structure and interesting redox-active property are synthesized to construct c-MOFs. A series of novel 2D c-MOFs (Cu-TOC, Zn-TOC and Mn-TOC) with different conductivities and packing modes are obtained by combining the linker tetraoxa[8]circulenes-2,3,5,6,8,9,11,12-octaol (8OH-TOC) and corresponding metal ions. Three c-MOFs all exhibit typical semiconducting properties, and Cu-TOC exhibits the highest electrical conductivity of 0.2 S cm-1 among them. Furthermore, their electrochemical performance as cathode materials for ZIBs have been investigated. They all performed high reversible capacity, decent cycle stability and excellent rate capability. This work reveals the key insights into the electrochemical application potential of 2D c-MOFs and advances their development as cathode materials in ZIBs.

Effect of Secondary Heat Treatment after a Washing on the Electrochemical Performance of Co-Free LiNi0.975 Al0.025 O2 Cathodes for Li-Ion Batteries.

The steadily growing electric vehicle market is a driving force in low-cost, high-energy-density lithium-ion battery development. To meet this demand, LiNi0.975 Al0.025 O2 (LNA), a high-energy-density and cobalt-free cathode material, has been developed using a low-cost and efficient co-precipitation and lithiation process. This article explores how further processing (i.e., washing residual lithium from the secondary particle surface and applying a secondary heat treatment at 650 °C) changes the chemical environment of the surface and the electrochemical performance of the LNA cathode material. After washing, a nonconductive nickel oxide (NiO) phase is formed on the surface, decreasing the initial capacity in electrochemical tests, and suppressing high-voltage (H2) to (H3) phase transition results in enhanced cycle properties. Furthermore, the secondary heat treatment re-lithiates surface NiO back to LNAand increases the initial capacity with enhanced cycle properties. Electrochemical tests are performed with the cells without tap charge to suppress the H2 to H3 phase transition. Results reveal that avoiding charging cells at a high voltage for a long time dramatically improves LNA's cycle life. In addition, the gas analysis tests performed during charge and discharge to reveal how the amount of residual lithium compounds on the surface affects gas formation are studied.

Construction of Binder-Free, Self-Supported, Hetero-Core-Shell Honeycomb Structured CuCo2 O4 @Ni0.5 Co0.5 (OH)2 with Abundant Mesopores and High Conductivity for High-Performance Energy Storage.

Clever and rational design of structural hierarchy, along with precise component adjustment, holds profound significance for the construction of high-performance supercapacitor electrode materials. In this study, a binder-free self-supported CCO@N0.5 C0.5 OH/NF cathode material is constructed with hierarchical hetero-core-shell honeycomb nanostructure by first growing CuCo2 O4 (CCO) nanopin arrays uniformly on highly conductive nickel foam (NF) substrate, and then anchoring Ni0.5 Co0.5 (OH)2 (N0.5 C0.5 OH) bimetallic hydroxide nanosheet arrays on the CCO nanopin arrays by adjusting the molar ratio of Ni(OH)2 and Co(OH)2 . The constructed CCO@N0.5 C0.5 OH/NF electrode material showcases a wealth of multivalent metal ions and mesopores, along with good electrical conductivity, excellent electrochemical reaction rates, and robust long-term performance (capacitance retention rate of 87.2%). The CCO@N0.5 C0.5 OH/NF electrode, benefiting from the hierarchical structure of the material and the exceptional synergy between multiple components, demonstrates an excellent specific capacitance (2553.6 F g-1 at 1 A g-1 ). Furthermore, the assembled asymmetric CCO@N0.5 C0.5 OH/NF//AC/NF supercapacitor demonstrates a high energy density (70.1 Wh kg-1 at 850 W kg-1 ), and maintains robust capacitance cycling stability performance (83.7%) after undergoing 10 000 successive charges and discharges. It is noteworthy that the assembled supercapacitor exhibits an operating voltage (1.7 V) that is well above the theoretical value (1.5 V).

A Comprehensive Review on Reductive Recycling of Cathode Materials of Spent Lithium-Ion Batteries.

The prosperity of the lithium-ion battery market is inevitably accompanied by the depletion of corresponding resources and the accumulation of spent batteries in a dialectical manner. Spent lithium-ion batteries are harboring the characteristics of hazardous waste and high-value resources, so efficient recycling is of great significance. The cathode material is considered as an interesting target for repurposing. Despite some important reviews give commendable emphasis to recycling technologies, there is still a dearth of exploration of recycling mechanisms. This deficiency of awareness highlights the need for further research and development in this area. This review aims to systematically review and thoroughly discuss the reduction reaction mechanism of each method regarding different cathode materials. And systematically digest the selection of reducing agent and the effect of reduction reaction on material regeneration are systematically digested, as well as the impact of the reduction reaction on the regeneration of materials. This review emphasizes the importance of balancing efficiency, economic and environmental benefits in reuse technologies. Finally, the review proposes an outlook on the opportunities and challenges facing the reuse of key materials for next-generation spent batteries aimed at promoting the green and sustainable development of lithium-ion batteries, circular economy and ecological balance.