Self-Sacrifice Template Construction of Uniform Yolk-Shell ZnS@C for Superior Alkali-Ion Storage

ZnS Nanoseeds Sealed in N, P, S Co-Doped Carbon Hollow Rhombic Dodecahedra as a Superlithiophilic Host for Dendrite-Free Lithium Metal Anodes

Lithium (Li) metal is considered a hopeful anode for next-generation Li-ion batteries thanks to its ultra-high theoretical specific capacity, extra-low theoretical density, and low negative potential. However, the uncontrolled growth of Li dendrites and volume fluctuation during plating/stripping processes severely hamper its commercial application. Herein, ZnS seeds sealed in N, P, S co-doped carbon hollow rhombic dodecahedra (ZnS@NPS-C HRD) is fabricated as a superlithiophilic host for Li metal anodes (LMAs) to solve the above problems. In addition, the Li nucleation and deposition mechanism on ZnS@NPS-C HRD is investigated by in situ optical microscopy, ex-situ X-ray diffraction, scanning electron microscopy, and theoretical calculations. Owing to the synergistic strategy of ZnS seeds-inducing nucleation and Li-limited growth, the as-prepared composite exhibits stability for 300 cycles in asymmetric cells and a long lifespan over 1100 h in symmetric cells. Moreover, the ZnS@NPS-C HRD@Li|LiFePO4 full cell demonstrates a reversible capacity of 100.91 mAh g-1 after 400 cycles at 1 C.

Advances in Inorganic Foam Materials Fabricated Via Blowing Strategy: A Comprehensive Review

Two-dimensional (2D) materials with excellent properties and widespread applications have been explosively investigated. However, their conventional synthetic methods exhibit concerns of limited scalability, complex purification process, and incompetence of prohibiting their restacking. The blowing strategy, characterized by gas-template, low-cost, and high-efficiency, presents a valuable avenue for the synthesis of 2D-based foam materials and thereby addresses these constraints. Whereas, its comprehensive introduction has been rarely outlined so far. This review commences with a synopsis of the blowing strategy, elucidating its development history, the statics and kinetics of the blowing process, and the choice of precursor and foaming agents. Thereafter, we dwell at length on across-the-board foams enabled by the blowing route, like BxCyNz foams, carbon foams, and diverse composite foams consisting of carbon and metal compounds. Following that, a wide-ranging evaluation of the functionality of the foam products in fields such as energy storage, electrocatalysis, adsorption, etc. is discussed, revealing their distinctive strength originated from the foam structure. Finally, after concluding the current progress, we provide some personal discussions on the existing challenges and future research priorities in this rapidly developing method.

Fluorinated Surface Engineering Towards High-Rate and Durable Potassium-Ion Battery

Solid electrolyte interphase (SEI) crucially affects the rate performance and cycling lifespan, yet to date more extensive research is still needed in potassium-ion batteries. We report an ultra-thin and KF-enriched SEI triggered by tuned fluorinated surface design in electrode. Our results reveal that fluorination engineering alters the interfacial chemical environment to facilitate inherited electronic conductivity, enhance adsorption ability of potassium, induce localized surface polarization to guide electrolyte decomposition behavior for SEI formation, and especially, enrich the KF crystals in SEI by self-sacrifice from C-F bond cleavage. Hence, the regulated fluorinated electrode with generated ultra-thin, uniform, and KF-enriched SEI shows improved capacity of 439.3 mAh g-1 (3.82 mAh cm-2), boosted rate performance (202.3 mAh g-1 at 8.70 mA cm-2) and durable cycling performance (even under high loading of ~8.7 mg cm-2). We expect this practical engineering principle to open up new opportunities for upgrading the development of potassium-ion batteries.

Island-Like Heterogeneous Interface Generating Tandem Toroidal Built-In Electric Field for Efficient Potassium Ions Diffusion

For large-size potassium accommodation, heterostructure usually suffers severe delamination and exfoliation at the interfaces due to different volume expansion of two-phase during charge/discharge process, resulting in the deconstruction of heterostructures and shortened lifespan of batteries. Here, an innovative strategy is proposed through constructing a microscopic heterostructure system containing copper quantum dots (Cu QDs) highly dispersed in the triphenyl-substituted triazine graphdiyne (TPTG) substrates (TPTG@CuQDs) to solve this problem. The copper quantum dots are uniformly anchored on TPTG substrates, generating a myriad of island-like heterogeneous structures, together with tandem toroidal built-in electric field (BIEF) between every micro heterointerface. The island-like heterostructure endows both benefits of exposed contact interface and robust architecture. Generated tandem toroidal BIEF provides efficient transport pathways with lower energy barriers, reducing the diffusion resistance and facilitating the reaction kinetics of potassium ions. When used as anode, the TPTG@CuQDs exhibit highly reversible capacity and low-capacity degradation (≈0.01% over 5560 cycles at 1 A g-1). Moreover, the TPTG@CuQDs-based full cell delivers an outstanding reversible capacity of ≈110 mAh g-1 over 800 cycles at 1 A g-1. This quantum-scale heterointerface construction strategy offers a new approach toward stable heterostructure design for the application of metal ion batteries.

Shell Modulation of Hollow Metal Sulfide Nanocomposite for Stable Potassium Storage at Room and High Temperature

The large size of K-ion makes the pursuit of stable high-capacity anodes for K-ion batteries (KIBs) a formidable challenge, particularly for high temperature KIBs as the electrode instability becomes more aggravated with temperature climbing. Herein, we demonstrate that a hollow ZnS@C nanocomposite (h-ZnS@C) with a precise shell modulation can resist electrode disintegration to enable stable high-capacity potassium storage at room and high temperature. Based on a model electrode, we identify an interesting structure-function correlation of the h-ZnS@C: with an increase in the shell thickness, the cyclability increases while the rate and capacity decrease, shedding light on the design of high-performance h-ZnS@C anodes via engineering the shell thickness. Typically, the h-ZnS@C anode with a shell thickness of 60 nm can deliver an impressive comprehensive performance at room temperature; the h-ZnS@C with shell thickness increasing to 75 nm can achieve an extraordinary stability (88.6 % capacity retention over 450 cycles) with a high capacity (450 mAh g-1) and a superb rate even at an extreme temperature of 60 °C, which is much superior than those reported anodes. This contribution envisions new perspectives on rational design of functional metal sulfides composite toward high-performance KIBs with insights into the significant structure-function correlation.

Engineering a Low-Strain Si@TiSi2@NC Composite for High-Performance Lithium-Ion Batteries

The huge volume expansion/contraction of silicon (Si) during the lithium (Li) insertion/extraction process, which can lead to cracking and pulverization, poses a substantial impediment to its practical implementation in lithium-ion batteries (LIBs). The development of low-strain Si-based composite materials is imperative to address the challenges associated with Si anodes. In this study, we have engineered a TiSi2 interface on the surface of Si particles via a high-temperature calcination process, followed by the introduction of an outermost carbon (C) shell, leading to the construction of a low-strain and highly stable Si@TiSi2@NC composite. The robust TiSi2 interface not only enhances electrical and ionic transport but also, more critically, significantly mitigates particle cracking by restraining the stress/strain induced by volumetric variations, thus alleviating pulverization during the lithiation/delithiation process. As a result, the as-fabricated Si@TiSi2@NC electrode exhibits a high initial reversible capacity (2172.7 mAh g-1 at 0.2 A g-1), superior rate performance (1198.4 mAh g-1 at 2.0 A g-1), and excellent long-term cycling stability (847.0 mAh g-1 after 1000 cycles at 2.0 A g-1). Upon pairing with LiNi0.6Co0.2Mn0.2O2 (NCM622), the assembled Si@TiSi2@NC||NCM622 pouch-type full cell exhibits exceptional cycling stability, retaining 90.1% of its capacity after 160 cycles at 0.5 C.

Highly Stable ZnS Anodes for Sodium-Ion Batteries Enabled by Structure and Electrolyte Engineering

Zinc sulfide is a promising high-capacity anode for practical sodium-ion batteries, considering its high capacity and the low cost of zinc and sulfur sources. However, the pulverization of particulate zinc sulfide causes active mass collapse and penetration-induced short circuits of batteries. Herein, a zinc sulfide encapsulated in a nitrogen-doped carbon shell (ZnS@NC) was developed for high-performance anodes. The confinement effect of nitrogen-doped carbon stabilizes the active mass structure during cycling thanks to the robust chemically and electronically bonded connections between nitrogen-doped carbon and zinc sulfide nanoparticles. Furthermore, the cycling stability of the ZnS@NC anode is boosted by the robust inorganic-rich solid electrolyte interphase (SEI) formed in cyclic and linear ether-based electrolytes. The ZnS@NC anode displayed a reversible specific capacity of 584 mAh g-1, an excellent rate capability of 327 mAh g-1 at 70 A g-1, and a highly stable cycling performance over 10000 cycles. This work provides a practical and promising approach to designing stable conversion anodes for high-performance sodium-ion batteries.

Interfacial Engineering of MoS2/V2O3@C-rGO Composites with Pseudocapacitance-Enhanced Li/Na-Ion Storage Kinetics

Molybdenum sulfide has been widely investigated as a prospective anode material for Li+/Na+ storage because of its unique layered structure and high theoretical capacity. However, the enormous volume variation and poor conductivity limit the development of molybdenum sulfide. The rational design of a heterogeneous interface is of great importance to improve the structure stability and electrical conductivity of electrode materials. Herein, a high-temperature mixing method is implemented in the hydrothermal process to synthesize the hybrid structure of MoS2/V2O3@carbon-graphene (MoS2/V2O3@C-rGO). The MoS2/V2O3@C-rGO composites exhibit superior Li+/Na+ storage performance due to the construction of the interface between the MoS2 and V2O3 components and the introduction of carbon materials, delivering a prominent reversible capacity of 564 mAh g-1 at 1 A g-1 after 600 cycles for lithium-ion batteries and 376.3 mAh g-1 at 1 A g-1 after 450 cycles for sodium-ion batteries. Theoretical calculations confirm that the construction of the interface between the MoS2 and V2O3 components can accelerate the reaction kinetics and enhance the charge-ionic transport of molybdenum sulfide. The results illustrate that interfacial engineering may be an effective guide to obtain high-performance electrode materials for Li+/Na+ storage.

Interface ion-exchange strategy of MXene@FeIn2S4 hetero-structure for super sodium ion half/full batteries

Herein, a well-designed hierarchical architecture of bimetallic transition sulfide FeIn2S4 nanoparticles anchoring on the Ti3C2 MXene flakes has been prepared by cation exchange and subsequent high-temperature sulfidation processes. The introduction of MXene substrate with excellent conductivity not only accelerates the migration rate of Na+ to achieve fast reaction dynamics but provides abundant deposition sites for the FeIn2S4 nanoparticles. In addition, this hierarchical structure of MXene@FeIn2S4 can effectively restrain the accumulation of MXene to guarantee the maximized exposure of redox active sites into the electrolyte, and simultaneously relieve the volume expansion in the repeated discharging/charging processes. The MXene@FeIn2S4 displays outstanding rate capability (448.2 mAh g-1 at 5 A g-1) and stable long cycling performance (428.1 mAh g-1 at 2 A g-1 after 200 cycles). Moreover, the Nay-In6S7 phase detected by ex-situ XRD and XPS characterization may be regarded as a "buffer" to maintain the stability of the Fe-based components and enhance the reversibility of the electrochemical reaction. This work confirms the practicability of constructing the hierarchical structure bimetallic sulfides with the promising electrochemical performance.

Green synthesis of carbon-supported ultrafine ZnS nanoparticles for superior lithium-ion batteries

Zinc sulfide (ZnS) is a promising anode material for lithium-ion batteries (LIBs) because of its high theoretical capacity, abundance, cost-effectiveness, and environmental friendliness. Herein, a hydrangea-like ZnS-carbon composite (ZnS-NC) is synthesized through the hydrothermal method and subsequent pyrolysis of a supramolecular precursor guanosine. The resulting composite comprises ultrafine ZnS nanoparticles firmly stabilized on a nitrogen-doped carbon matrix, featuring mesoporous channels and high surface areas. When utilized as an anode material for LIBs, the initial discharge specific capacity of the ZnS-NC electrode reaches an impressive value of 944 mA h g-1 at 1.0 A g-1, and even after 450 cycles, it maintains a reversible capacity of 597 mA h g-1. Compared with pure ZnS, the ZnS-NC composite exhibits significantly improved rate performance and cycling stability. This enhancement in Li-storage performance can be attributed to a synergistic effect within the ZnS-NC composite, which arises from the large exposed active site area, efficient ion/electron transfer, and strong interaction between the ZnS nanoparticles and the carbon framework. Overall, this work presents an eco-friendly approach for developing metal sulfide-carbon composites with exceptional potential for energy storage applications.

Topological Insulator Bi2 Se3 -Assisted Heterostructure for Ultrafast Charging Sodium-Ion Batteries

The development of fast charging materials offers a viable solution for large-scale and sustainable energy storage needs. However, it remains a critical challenge to improve the electrical and ionic conductivity for better performance. Topological insulator (TI), a topological quantum material that has attracted worldwide attention, hosts unusual metallic surface states and consequent high carrier mobility. Nevertheless, its potential in promising high-rate charging capability has not been fully realized and explored. Herein, a novel Bi2 Se3 -ZnSe heterostructure as excellent fast charging material for Na+ storage is reported. Ultrathin Bi2 Se3 nanoplates with rich TI metallic surfaces are introduced as an electronic platform inside the material, which greatly reduces the charge transfer resistance and improves the overall electrical conductivity. Meanwhile, the abundant crystalline interfaces between these two selenides promote Na+ migration and provide additional active sites as well. As expected, the composite delivers the excellent high-rate performance of 360.5 mAh g-1 at 20 A g-1 and maintains its electrochemical stability of 318.4 mAh g-1 after 3000 long cycles, which is the record high for all reported selenide-based anodes. This work is anticipated to provide alternative strategies for further exploration of topological insulators and advanced heterostructures.

In situ acid etching boosts mercury accommodation capacities of transition metal sulfides

Transition Metal sulfides (TMSs) are effective sorbents for entrapment of highly polluting thiophiles such as elemental mercury (Hg⁰). However, the application of these sorbents for mercury removal is stymied by their low accommodation capacities. Among the transition metal sulfides, only CuS has demonstrated industrially relevant accommodation capacity. The rest of the transition metal sulfides have 100-fold lower capacities than CuS. In this work, we overcome these limitations and develop a simple and scalable process to enhance Hg⁰ accommodation capacities of TMSs. We achieve this by introducing structural motifs in TMSs by in situ etching. We demonstrate that in situ acid etching produces TMSs with defective surface and pore structure. These structural motifs promote Hg⁰ surface adsorption and diffusion across the entire TMSs architecture. The process is highly versatile and the in situ etched transition metal sulfides show over 100-fold enhancement in their Hg⁰ accommodation capacities. The generality and the scalability of the process provides a framework to develop TMSs for a broad range of applications.

A Selective Oxidation Strategy towards the Yolk-Shell Structured ZnS@C Material for Ultra-Stable Li-Ion Storage

Metal chalcogenides are attractive anode materials for lithium-ion batteries (LIBs) due to their high theoretical capacities. With the advantages of low cost and abundance reserves, ZnS is regarded as the prime candidate anode material for future generations, but its practical application is hindered by the large volume expansion during repeated cycling processes and inherent poor conductivity. Rational design of the microstructure with large pore volume and high specific surface area is of great significance to solve these problems. Here, a carbon-coated ZnS yolk-shell structure (YS-ZnS@C) has been prepared by selective partial oxidation of a core-shell structured ZnS@C precursor in air and subsequent acid etching. Studies show that the carbon wrapping and proper etching to bring cavities can not only improve the material's electrical conductivity, but can also effectively alleviate the volume expansion problem of ZnS during its cycles. As a LIB anode material, the YS-ZnS@C exhibits an obvious superiority in capacity and cycle life compared to ZnS@C. The YS-ZnS@C composite shows a discharge capacity of 910 mA h g^-1 at the current density of 100 mA g^-1 after 65 cycles, compared to only 604 mA h g^-1 for ZnS@C after 65 cycles. Notably, at a large current density of 3000 mA g^-1, a capacity of 206 mA h g^-1 can still be maintained after 1000 cycles (over three times of the capacity for ZnS@C). It is expected that the synthetic strategy developed here is applicable to designing various high-performance metal chalcogenide-based anode materials for LIBs.

Recent advances in epitaxial heterostructures for electrochemical applications

Construction of epitaxial heterostructures is crucial for boosting the electrochemical properties of various materials, however a review dedicated to this attractive topic is still lacking. In this Minireview, a timely summary on the achievements of epitaxial heterostructure design for electrochemical applications is provided. We first introduce the synthesis strategies to provide fundamental understanding on how to create epitaxial interfaces between different components. Secondly, the superiorities of epitaxial heterostructures in electrocatalysis, supercapacitors and batteries are highlighted with the underlying structure-property relationship elucidated. Finally, a discussion on the challenges and future prospects of this field is presented.

Novel Bifunctional Nitrogen Doped MoS2/COF-C4N Vertical Heterostructures for Electrocatalytic HER and OER

Highly active and earth-abundant catalysts for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) play vital roles in developing efficient water splitting to produce hydrogen fuels. Here, we reported an effective strategy to fabricate a completely new nitrogen-doped MoS2/COF-C4N vertical heterojunction (N-MoS2/COF-C4N) as precious-metal-free bifunctional electrocatalysts for both HER and OER. Compared with MoS2 and COF-C4N, the obtained vertical N-MoS2/COF-C4N catalyst showed enhanced HER with a low overpotential of 106 mV at 10 mA cm−2, which is six times lower than MoS2. The superior acidic HER activity, molecular mechanism, and charge transfer characteristic of this vertical N-MoS2/COF-C4N were investigated experimentally and theoretically in detail. Its basic OER activity is almost equal to that of COF-C4N with an overpotential of 349 mV at 10 mA cm−2, which showed that the in-situ growing method maintains the exposure of the C active sites to the greatest extent. The preparation and investigation for vertical N-MoS2/COF-C4N provide ideas and a research basis for us to further explore promising overall water-splitting electrocatalysts.

Defect-Rich Single Atom Catalyst Enhanced Polysulfide Conversion Kinetics to Upgrade Performance of Li-S Batteries

Lithium-sulfur (Li-S) batteries have attracted considerable attention owing to their extremely high energy densities. However, the application of Li-S batteries has been limited by low sulfur utilization, poor cycle stability, and low rate capability. Accelerating the rapid transformation of polysulfides is an effective approach for addressing these obstacles. In this study, a defect-rich single-atom catalytic material (Fe-N4/DCS) is designed. The abundantly defective environment is favorable for the uniform dispersion and stable existence of single-atom Fe, which not only improves the utilization of single-atom Fe but also efficiently adsorbs polysulfides and catalyzes the rapid transformation of polysulfides. To fully exploit the catalytic activity, catalytic materials are used to modify the routine separator (Fe-N₄ /DCS/PP). Density functional theory and in situ Raman spectroscopy are used to demonstrate that Fe-N₄ /DCS can effectively inhibit the shuttling of polysulfides and accelerate the redox reaction. Consequently, the Li-S battery with the modified separator achieves an ultralong cycle life (a capacity decay rate of only 0.03% per cycle at a current of 2 C after 800 cycles), and an excellent rate capability (894 mAh g^-1 at 3 C). Even at a high sulfur loading of 5.51 mg cm^-2 at 0.2 C, the reversible areal capacity still reaches 5.4 mAh cm^-2 .

Flexible MoS2 Anchored on Ge-Containing Carbon Nanofibers

Germanium is a promising anode material for sodium-ion batteries (SIBs) because of its high theoretical specific capacity, high ion diffusivity, and rate capability. However, large volume changes and pulverization deteriorate the cycling performance. In this study, flexible electrospun germanium/carbon nanofibers (Ge/CNFs) were prepared via electrospinning followed by heat treatment. MoS₂ nanoparticles were subsequently anchored on the flexible Ge/CNFs via hydrothermal synthesis. Flexible MoS₂ anchored on Ge/CNFs (MoS₂@Ge/CNFs) was used as a self-standing binder-free anode in an SIB. Because of the high electronic conductivity of CNFs and the many active sites of MoS₂ nanoparticles, a high initial capacity of over 880 mAh/g was achieved at a current density of 0.1 A/g. Moreover, the flexible binder-free MoS₂@Ge/CNFs exhibited an excellent C-rate performance with a reversible capacity of over 300 mAh/g at a current density of 2 A/g. Therefore, we demonstrated that flexible binder-free MoS₂@Ge/CNFs are a promising electrode candidate for a high-performance rechargeable battery.

Pseudocapacitance-Enhanced Storage Kinetics of 3D Anhydrous Iron (III) Fluoride as a Cathode for Li/Na-Ion Batteries

Transition metal fluoride (TMF) conversion cathodes, with high energy density, are recognized as promising candidates for next-generation high-energy Li/Na-ion batteries (LIBs/SIBs). Unfortunately, the poor electronic conductivity and detrimental active material dissolution of TMFs seriously limit the performance of TMF-LIBs/SIBs. A variety of FeF3-based composites are designed to improve their electrochemical characteristics. However, the storage mechanism of the conversion-type cathode for Li+ and Na+ co-storage is still unclear. Here, the storage mechanism of honeycomb iron (III) fluoride and carbon (FeF3@C) as a general cathode for LIBs/SIBs is analyzed by kinetics. In addition, the FeF3@C cathode shows high electrochemical performance in a full-cell system. The results show that the honeycomb FeF3@C shows excellent long-term cycle stability in LIBs (208.3 mA h g-1 at 1.0 C after 100 cycles with a capacity retention of 98.1%). As a cathode of SIBs, the rate performance is unexpectedly stable. The kinetic analysis reveals that the FeF3@C cathode exhibit distinct ion-dependent charge storage mechanisms and exceptional long-durability cyclic performance in the storage of Li+/Na+, benefiting from the synergistic contribution of pseudocapacitive and reversible redox behavior. The work deepens the understanding of the conversion-type cathode in Li+/Na+ storage.

A Novel Membrane-like 2D A'-MoS2 as Anode for Lithium- and Sodium-Ion Batteries

Currently, new nanomaterials for high-capacity lithium-ion batteries (LIBs) and sodium- ion batteries (SIBs) are urgently needed. Materials combining porous structure (such as representatives of metal-organic frameworks) and the ability to operate both with lithium and sodium (such as transition-metal dichalcogenides) are of particular interest. Our work reports the computational modelling of a new A'-MoS₂ structure and its application in LIBs and SIBs. The A'-MoS₂ monolayer was dynamically stable and exhibited semiconducting properties with an indirect band gap of 0.74 eV. A large surface area, together with the presence of pores resulted in a high capacity of the A'-MoS₂ equal to ~391 mAg^-1 at maximum filling for both Li and Na atoms. High adsorption energies and small values of diffusion barriers indicate that the A'-MoS₂ is promising in the application of anode material in LIBs and SIBs.

A Versatile Strategy for Achieving Fast-Charging Batteries via Interfacial Engineering: Pseudocapacitive Potassium Storage without Nanostructuring

The rapid transport of alkali ions in electrodes is a long-time dream for fast-charging batteries. Though electrode nanostructuring has increased the rate-capability, its practical use is limited because of the low tap density and severe irreversible reactions. Therefore, development of a strategy to design fast-charging micron-sized electrodes without nanostructuring is of significant importance. Herein, a simple and versatile strategy to accelerate the alkali ion diffusion behavior in micron-sized electrode is reported. It is demonstrated that the diffusion rate of K⁺ ions is significantly improved at the hetero-interface between orthorhombic Nb₂ O₅ (001) and monoclinic MoO₂ (110) planes. Lattice distortion at the hetero-interface generates an inner space large enough for the facile transport of K⁺ ions, and electron localization near oxygen-vacant sites further enhances the ion diffusion behavior. As a result, the interfacial-engineered micron-sized anode material achieves an outstanding rate capability in potassium-ion batteries (KIBs), even higher than nanostructured orthorhombic Nb₂ O₅  which is famous for fast-charging electrodes. This is the first study to develop an intercalation pseudocapacitive micron-sized anode without nanostructuring for fast-charging and high volumetric energy density KIBs. More interestingly, this strategy is not limited to K⁺ ion, but also applicable to Li⁺ ion, implying the versatility of interfacial engineering for alkali ion batteries.

Challenges and Modification Strategies of Ni-Rich Cathode Materials Operating at High-Voltage

Ni-rich cathode materials have become promising candidates for lithium-based automotive batteries due to the obvious advantage of electrochemical performance. Increasing the operating voltage is an effective means to obtain a higher specific capacity, which also helps to achieve the goal of high energy density (capacity × voltage) of power lithium-ion batteries (LIBs). However, under high operating voltage, surface degradation will occur between Ni-rich cathode materials and the electrolytes, forming a solid interface film with high resistance, releasing O₂, CO₂ and other gases. Ni-rich cathode materials have serious cation mixing, resulting in an adverse phase transition. In addition, the high working voltage will cause microcracks, leading to contact failure and repeated surface reactions. In order to solve the above problems, researchers have proposed many modification methods to deal with the decline of electrochemical performance for Ni-rich cathode materials under high voltage such as element doping, surface coating, single-crystal fabrication, structural design and multifunctional electrolyte additives. This review mainly introduces the challenges and modification strategies for Ni-rich cathode materials under high voltage operation. The future application and development trend of Ni-rich cathode materials for high specific energy LIBs are projected.