Active Material Research Articles

TiH2-based anode: In situ formation of solid electrolyte for high volumetric energy density with minimal content of conducting agent

Herein, we report the fabrication of an electrode composite with an ultra-high active material content (90 wt%). This composite was possible because of the utilization of TiH2 as an anode active material that forms a solid electrolyte (LiH) in situ and functions as an electronic conductor, enabling a substantial reduction of the amount of conductor additive in the electrodes. The electrochemical performance of the TiH2-based electrodes with a high active material content was comparable to that of electrode composites that include a solid electrolyte because of sufficient Li+-ion conduction pathways provided by the LiH formed in situ. To further increase the capacity of the TiH2-based electrode, MgH2 (theoretical capacity: 2036 mAh/g) was mixed with TiH2 to function as an active material. TiH2, which is known to exhibit high electron conductivity and a high density, is expected to be used as a partial substitute for low-density carbon additives to increase the volumetric energy density of batteries and their active material content. Hence, the xMgH2-(1 − x)TiH2-AB (AB: acetylene black) electrode composite exhibited a high active material content (90 wt%) and improved volumetric energy density (1687 Wh/L, based on the anode) compared with a MgH2-AB (70:30 wt%) electrode composite (1157 Wh/L), even when the AB content of the xMgH2-(1 − x)TiH2-AB composite was 10 wt%. In addition, a MgH2-TiH2-VGCF (VGCF: vapor-grown carbon fiber) based electrode composite exhibited the highest volumetric and gravimetric energy density (2154 Wh/L, 1888 Wh/kg) among the investigated composites, facilitated by sufficient electron pathways provided by VGCF.

Unraveling the influence of Sb dopant to reversible capacity and initial Coulombic efficiency of SnO2-graphene as anodes for sodium storage

Sodium storage materials based on conversion and alloying reactions often suffer from low initial Coulombic efficiency (ICE). Most of literature shows that the SnO2-based anode commonly reveals an ICE below 50 %, and the reasons could be attributed to the partial reversibility in conversion reaction by forming an intermediate phase. This work focuses on using an element doping strategy to suppress the formation of an inert intermediate phase and improve the ICE for SnO2-based anodes in sodium storage applications. Mechanisms of performance enhancement are also carefully investigated. The 3 % Sb doped sample is demonstrated with enhanced electrochemical performance. Specifically, it delivers an initial discharge capacity of 847 mAh/g at 50 mA g−1, combining an average enhanced ICE of 57.1 % (37.8 % for the undoped comparison), and it also presents a good rate performance of 206 mAh/g at a high current density of 1600 mA g−1. It is found that the Sb dopant reduces the specific capacity of active materials, but it enhances reaction reversibility; improves the overall conductivity of active materials, but does not directly enhance the Na+ diffusion coefficient; helps to restrain the formation of inert phase (the SnO phase) in sodium storage reactions to improve reversibility and initial Coulombic efficiency. Therefore, reversible capacities and initial Coulombic efficiencies can be effectively enhanced after introducing the Sb dopant at an optimized percentage. This work could provide valuable inspiration for designing conversion and alloying-type anodes for sodium storage applications via ion doping methods.

Free-standing ultra-thin carbon nanofiber films with controllable thickness for lithium ion batteries

Thin and porous anode materials enable short ion migration distances and high-rate performance. However, the current freestanding anode materials are too thick (typically around 100 μm) for high-rate lithium ion batteries (LIBs). Here, we have developed a facile and scalable process to synthesize ultra-thin (<400 nm) freestanding films. In comparison to other chemical and physical deposition methods that yield thin films (<500 nm), our freestanding films do not require the substrate material, achieving a 100% loading of active material. Our ultra-thin carbon nanofiber films exhibit an exceptional specific capacity of 599 mAh/g even after 10,000 cycles at a current density of 10 A/g. Compared to thick carbon nanofiber films, the utilization of ultra-thin carbon nanofiber films as anode materials exhibits a remarkable enhancement of more than tenfold in cycling performance

Developments, Novel Concepts, and Challenges of Current Collectors: From Conventional Lithium Batteries to All‐Solid‐State Batteries

AbstractWith the innovation and evolution of lithium batteries, different active materials are loaded onto the current collectors, leading to remarkable changes in the components that directly interact with the current collectors. The surface/interface of current collectors in lithium batteries is gradually becoming one of the key factors to improve the overall performance. The thickness, material composition, surface morphology, and intrinsic properties of current collectors are crucial for understanding chemo‐mechanical changes during electrochemical reactions. Despite the widely acknowledged importance of highly efficient electron transportation and improved interfacial performance of current collectors as one of the determinants of exceptional lithium battery performance, insufficient attention has been given to exploring targeted design strategies for current collectors used in various lithium batteries. Particularly, as the development of solid‐state lithium batteries in full swing, there are limited studies focused on current collectors in all‐solid‐state lithium batteries (ASSLBs). This review introduces recent advancements in current collector technology, while highlighting both similarities and differences between negative current collectors applied in conventional lithium batteries and ASSLBs. Furthermore, we propose promising prospects for utilization of alloy materials as next‐generation negative current collectors.

Towards More Sustainable Aqueous Zinc‐Ion Batteries

AbstractAqueous zinc‐ion batteries (AZIBs) are considered as the promising candidates for large‐scale energy storage because of their high safety, low cost and environmental benignity. The large‐scale applications of AZIBs will inevitably result in a large amount of spent AZIBs, which not only induce the waste of resources, but also pose environmental risks. Therefore, sustainable AZIBs have to be considered to minimize the risk of environmental pollution and maximize the utilization of spent compounds. Herein, this minireview focuses on the sustainability of AZIBs from material design and recycling techniques. The structure and degradation mechanism of AZIBs are discussed to guide the recycling design of the materials. Subsequently, the sustainability of component materials in AZIBs is further analysed to pre‐evaluate their recycling behaviors and mentor the selection of more sustainable component materials, including active materials in cathodes, Zn anodes, and aqueous electrolytes, respectively. According to the features of component materials, corresponding green and economic approaches are further proposed to realize the recycling of active materials in cathodes, Zn anodes and electrolytes, respectively. These advanced technologies endow the recycling of component materials with high efficiency and a closed‐loop control, ensuring that AZIBs will be the promising candidates of sustainable energy storage devices. This review will offer insight into potential future directions in the design of sustainable AZIBs.

Towards More Sustainable Aqueous Zinc-Ion Batteries.

Aqueous zinc-ion batteries (AZIBs) are considered as the promising candidates for large-scale energy storage because of their high safety, low cost and environmental benignity. The large-scale applications of AZIBs will inevitably result in a large amount of spent AZIBs, which not only induce the waste of resources, but also pose environmental risks. Therefore, sustainable AZIBs have to be considered to minimize the risk of environmental pollution and maximize the utilization of spent compounds. Herein, this minireview focuses on the sustainability of AZIBs from material design and recycling techniques. The structure and degradation mechanism of AZIBs are discussed to guide the recycling design of the materials. Subsequently, the sustainability of component materials in AZIBs is further analysed to pre-evaluate their recycling behaviors and mentor the selection of more sustainable component materials, including active materials in cathodes, Zn anodes, and aqueous electrolytes, respectively. According to the features of component materials, corresponding green and economic approaches are further proposed to realize the recycling of active materials in cathodes, Zn anodes and electrolytes, respectively. These advanced technologies endow the recycling of component materials with high efficiency and a closed-loop control, ensuring that AZIBs will be the promising candidates of sustainable energy storage devices. This review will offer insight into potential future directions in the design of sustainable AZIBs.

Double-Shelled Fe-Fe3C Nanoparticles Embedded on a Porous Carbon Framework for Superior Lithium-Ion Half/Full Batteries.

Cost-effective and environmentally friendly Fe-based active materials offer exceptionally high energy capacity in lithium-ion batteries (LIBs) due to their multiple electron redox reactions. However, challenges, such as morphology degradation during cycling, cell pulverization, and electrochemical stability, have hindered their widespread use. Herein, we demonstrated a simple salt-assisted freeze-drying method to design a double-shelled Fe/Fe3C core tightly anchored on a porous carbon framework (FEC). The shell consists of a thin Fe3O4 layer (≈2 nm) and a carbon layer (≈10 nm) on the outermost part. Benefiting from the complex nanostructuring (porous carbon support, core-shell nanoparticles, and Fe3C incorporation), the FEC anode delivered a high discharge capacity of 947 mAh g-1 at 50 mA g-1 and a fast-rate capability of 305 mAh g-1 at 10 A g-1. Notably, the FEC cell still showed 86% reversible capacity retention (794 mAh g-1 at 50 mA g-1) at a high cycling temperature of 80 °C, indicating superior structural integrity during cycling at extreme temperatures. Furthermore, we conducted a simple solid-state fluorination technique using the as-prepared FEC sample and excess NH4F to prepare iron fluoride-carbon composites (FeF2/C) as the positive electrode. The full cell configuration, consisting of the FEC anode and FeF2/C cathode, reached a remarkable capacity of 200 mAh g-1 at a 20 mA g-1 rate or an energy density of approximately 530 Wh kg-1. Thus, the straightforward and simple experimental design holds great potential as a revolutionary Fe-based cathodic-anodic pair candidate for high-energy LIBs.

A 2.5V In-Plane Flexi-Pseudocapacitor with Unprecedented Energy and Cycling Efficiency for All-Weather Applications.

As electronic devices for aviation, space, and satellite applications become more sophisticated, built-in energy storage devices also require a wider temperature spectrum. Herein, an all-climate operational, energy and power-dense, flexible, in-plane symmetric pseudocapacitor is demonstrated with utmost operational safety and long cycle life. The device is constructed with interdigital-patterned laser-scribed carbon-supported electrodeposited V5O12·6H2O as a binder-free electrode and a novel high-voltage anti-freezing water-in-salt-hybrid electrolyte. The anti-freezing electrolyte can operate over a wide temperature range of -40-60°C while offering a stable potential window of ≈2.5V. The device undergoes rigorous testing under diverse environmental conditions, including rapid and regular temperature and mechanical transition over multiple cycles. Additionally, detailed theoretical simulation studies are performed to understand the interfacial interactions with the active material as well as the local behavior of the anti-freeze electrolyte at different temperatures. As a result, the all-weather pseudocapacitor at 1Ag-1 shows a high areal capacitance of 234.7mFcm-2 at room temperature and maintains a high capacitance of 129.8mFcm-2 even at -40°C. Besides, the cell operates very reliably for over 80950 cycles with a capacitance of 25.7mFcm-2 at 10Ag-1 and exhibits excellent flexibility and bendability under different stress conditions.

Four Generations of Volcano Plots for the Oxygen Evolution Reaction: Beyond Proton-Coupled Electron Transfer Steps?

ConspectusDue to its importance for electrolyzers or metal-air batteries for energy conversion or storage, there is huge interest in the development of high-performance materials for the oxygen evolution reaction (OER). Theoretical investigations have aided the search for active material motifs through the construction of volcano plots for the kinetically sluggish OER, which involves the transfer of four proton-electron pairs to form a single oxygen molecule. The theory-driven volcano approach has gained unprecedented popularity in the catalysis and energy communities, largely due to its simplicity, as adsorption free energies can be used to approximate the electrocatalytic activity by heuristic descriptors.In the last two decades, the binding-energy-based volcano method has witnessed a renaissance with special concepts being developed to incorporate missing factors into the analysis. To this end, this Account summarizes and discusses the different generations of volcano plots for the example of the OER. While first-generation methods relied on the assessment of the thermodynamic information for the OER reaction intermediates by means of scaling relations, the second and third generations developed strategies to include overpotential and kinetic effects into the analysis of activity trends. Finally, the fourth generation of volcano approaches allowed the incorporation of various mechanistic pathways into the volcano methodology, thus paving the path toward data- and mechanistic-driven volcano plots in electrocatalysis.Although the concept of volcano plots has been significantly expanded in recent years, further research activities are discussed by challenging one of the main paradigms of the volcano concept. To date, the evaluation of activity trends relies on the assumption of proton-coupled electron transfer steps (CPET), even though there is experimental evidence of sequential proton-electron transfer (SPET) steps. While the computational assessment of SPET for solid-state electrodes is ambitious, it is strongly suggested to comprehend their importance in energy conversion and storage processes, including the OER. This can be achieved by knowledge transfer from homogeneous to heterogeneous electrocatalysis and by focusing on the material class of single-atom catalysts in which the active center is well defined. The derived concept of how to analyze the importance of SPET for mechanistic pathways in the OER over solid-state electrodes could further shape our understanding of the proton-electron transfer steps at electrified solid/liquid interfaces, which is crucial for further progress toward sustainable energy and climate neutrality.

Challenges of Predicting Temperature Dependent Capacity Loss Using the Example of NMC-LMO Lithium-Ion Battery Cells

Abstract In semi-empirical aging modeling of lithium ion-batteries an Arrhenius approach is commonly applied to describe the temperature dependency of a linear capacity loss. However, this dependency can change with degradation modes which was also observed in this cyclic aging study on NMC111-LMO graphite pouch cells in a temperature range of 4 °C to 48 °C. By means of differential voltage analysis and post-mortem analysis we correlated different regimes in capacity loss to degradation modes and aging mechanisms. In the first regime a power dependency of time was observed. A second accelerated linear regime which followed an increase in loss of active material of the positive electrode was seen for medium (~19 °C to 25 °C) to high aging temperatures. Transition metal dissolution was suggested to cause accelerated SEI growth. An activation energy could be estimated to 0.83 eV (± 0.17 eV, 95 % CI). Finally, at aging temperatures around 45 °C we propose decreased charge transfer kinetics to result in mossy dendrites on the negative electrode which cause a final knee in aging trajectory. The findings highlight the necessity of sufficient aging temperatures and testing time.

VOx anchored Ti3C2Tx MXene heterostructures for high-performance 2.2 V supercapacitors

Pseudocapacitive materials with superior electrochemical properties have attracted significant interest in developing high-performance supercapacitors. Herein, VOx anchored Ti3C2Tx MXene pseudocapacitive materials are synthesized via a solvothermal method to synergize metallic electrical conductivity and redox activity. Pure vanadium oxide synthesis results in VO2 formation, while in the presence of Ti3C2Tx, quasi-metallic V2O3 and VO2 (VOx) are observed due to the decomposition of surface functionalities of Ti3C2Tx. The growth of the V2O3 phase increases with an increase in the weight concentration of Ti3C2Tx. The optimal composition of heterostructure delivers a specific capacitance of 364 F g−1 in a stable potential window of −0.9 V–1 V, surpassing the specific capacitance of pure VO2 (245 F g−1) and Ti3C2Tx (140 F g−1) in 0.5 M K2SO4 electrolyte. Furthermore, the developed symmetric supercapacitor (SSC) delivers an energy density of 45.7 Wh kg−1 at a power density of 1.1 kW kg−1 with cyclic stability of 78 % for 10000 cycles with a self-discharge open circuit potential of 1.34 V. This work highlights a strategy to develop anodic and cathodic active pseudocapacitive material based SSC to improve energy density and mitigate self-discharge.

Silicon Nanowires as Anodes for Lithium‐Ion Batteries: Full Cell Modeling

Silicon (Si) anodes attract a lot of research attention for their potential to enable high‐energy density lithium‐ion batteries (LIBs). Many studies focus on nanostructured Si anodes to counteract deterioration. Herein, LIBs are modeled with Si nanowire anodes in combination with an ionic liquid (IL) electrolyte. On the anode side, elastic deformations to reflect the large volumetric changes of Si are allowed. With physics‐based continuum modeling, insight into usually hardly accessible quantities like the stress distribution in the active material can be provided. For the IL electrolyte, the thermodynamically consistent transport theory includes convection as relevant transport mechanism. The volume‐averaged 1d+1d framework is presented and parameter studies are performed to investigate the influence of the Si anode morphology on the cell performance. The findings highlight the importance of incorporating the volumetric expansion of Si in physics‐based simulations. Even for nanostructured anodes — which are said to be beneficial concerning the stresses — the expansion influences the achievable capacity of the cell. Accounting for enough pore space is important for efficient active material usage.

Scalable Approach to Molecular Motor-Polymer Conjugates for Light-Driven Artificial Muscles.

The integration of molecular machines and motors into materials represents a promising avenue for creating dynamic and functional molecular systems, with potential applications in soft robotics or reconfigurable biomaterials. However, the development of truly scalable and controllable approaches for incorporating molecular motors into polymeric matrices has remained a challenge. Here, we show that light-driven molecular motors with sensitive photo-isomerizable double bonds can be converted into initiators for Cu-mediated controlled/living radical polymerization enabling the synthesis of star-shaped motor-polymer conjugates. This approach enables scalability, precise control over molecular structure, block copolymer structures, and high end group fidelity. Moreover, we demonstrate that these materials can be crosslinked to form gels with quasi-ideal network topology, exhibiting light-triggered contraction. We investigate the influence of arm length and polymer structure, and develop the first molecular dynamics simulation framework to gain deeper insights into the contraction processes. Leveraging this scalable methodology, we showcase the creation of bilayer soft robotic devices and cargo-lifting artificial muscles, highlighting the versatility and potential applications of this advanced polymer chemistry approach. We anticipate that our integrated experimental and simulation framework will accelerate scalable approaches for active polymer materials based on molecular machines, opening up new horizons in materials science and bioscience. This article is protected by copyright. All rights reserved.

Inhibition of Vanadium Cathode Dissolution in Zinc‐Ion Batteries on Thermodynamics and Kinetics by Guest Pre‐Intercalation

AbstractAqueous zinc‐ion batteries (AZIBs), recognized for their safety and environmental friendliness, hold significant promise for large‐scale energy storage. However, the rapid capacity degradation resulting from the dissolution of active cathode materials hampers the advancement of AZIBs. Here, Ru0.2V2O5∙0.41H2O (RuVO) is synthesized with remarkable capacity retention (98.2% over 5000 cycles at 10 A g−1). The pre‐intercalation of Ru3+ enhances the stability of both intrinsic and cycling structures, elevating the Gibbs free energy and suppressing V‐dissolution thermodynamically. Additionally, Ru3+ intercalation modulates the potential energy surface of Zn2+ migration, leading to the dominance of Zn2+ in the insertion/extraction mechanism, thereby kinetically impeding the dissolution reaction. This study elucidates the dissolution thermodynamics and kinetics of V‐based cathodes through a combination of experiments, mechanism analyses, and density functional theory (DFT) calculations.

Synthesis of Nanosized γ-Cyclodextrin Metal-Organic Frameworks as Carriers of Limonene for Fresh-Cut Fruit Preservation Based on Polycaprolactone Nanofibers.

To address the issue of bacterial growth on fresh-cut fruits, this paper reports the synthesis of nanosized γ-cyclodextrin metal-organic frameworks (CD-MOFs) using an ultrasound-assisted method and their application as carriers of limonene for antibacterial active packaging. The effects of the processing parameters on the morphology and crystallinity of the CD-MOFs are investigated, and the results prove that the addition of methanol is the key to producing nanosized CD-MOFs. The limonene loading content of the nanosized CD-MOFs can reach approximately 170mg g-1. The sustained-release behaviors of limonene in the CD-MOFs are evaluated. Molecular docking simulations reveal the distribution and binding sites of limonene in the CD-MOFs. CD-MOFs are deposited on the surfaces of polycaprolactone (PCL) nanofibers via an immersion method, and limonene-loaded CD-MOF@PCL nanofibers are prepared. The morphology, crystallinity, thermal stability, mechanical properties, and antibacterial activity of the nanofibers are also studied. The nanofiber film effectively inhibits bacterial growth and prolongs the shelf life of fresh-cut apples. This study provides a novel strategy for developing antibacterial active packaging materials based on CD-MOFs and PCL nanofibers.

Advancing Post‐Secondary Batteries under Lean Electrolyte Conditions through Interfacial Modification Strategies

AbstractIn response to the growing global demand for portable electronics and electric vehicles, there is an escalating interest in developing advanced battery technologies with superior energy density. Research efforts are focused on unveiling post‐lithium‐ion batteries (LIBs) that outperform the performance of current LIBs through the use of innovative active electrode materials. Yet, these technological advancements face significant hurdles, primarily due to intricate interfacial issues within battery components. In laboratory‐scale studies, these challenges often lead to the utilization of excess electrolytes, which complicates the precise evaluation of battery performance. This review emphasizes the significance of designing future batteries that operate effectively under lean electrolyte usage conditions. It discusses essential principles, obstacles, and diverse strategies for interfacial modification, including in situ growth, coating of supportive layers, and embedding of active substances in pre‐structured templates. Furthermore, it compiles and examines data on the lean electrolyte conditions achieved in various battery systems, contrasting their energy densities with those of commercially established batteries. Ultimately, the potential of future batteries to achieve or even exceed the energy densities of existing commercial batteries is assessed, thereby offering a strategic roadmap for the progression of next‐generation battery technologies.

Exceeding 50 000 Cycle Durability of Layered Hydroxide‐Based Hybrid Supercapacitor Through Scandium Doping‐Induced Superlong Activation Process

Layered double hydroxides (LDHs) are a class of promising cathode materials for supercapacitors. However, the bad cycling performance has always been the Achilles’ heel of LDHs‐based supercapacitors. In this contribution, a nonelectrochemical active element Scandium (Sc) is doped into NiCo‐LDHs to greatly improve the intrinsic cycling performance of active materials. The trimetallic NiCoSc‐LDHs exhibit an ultralong cycle lifespan with 40 000 charge–discharge cycles (exceeding 50 days) and a high specific capacity of 196 mAh g−1 (1695 F g−1). Sc doping greatly changes the degradation mode of NiCo‐LDHs from rapid decay in thousands of cycles to a two‐stage performance evolution, which consists of a superlong activation process of about 10 000 cycles and then extremely slow degradation. Moreover, Sc doping enhances the electrochemical activity of Ni3+, so as to not only avoid its Jahn–Teller distortion, but also perform as a structural stabilizer to alleviate the local strain of host layer. The assembled asymmetric supercapacitor delivers an ultralong cycling lifespan with 101% capacity retention even after 50 000 cycles. This work presents a new pathway to significantly improve the electrochemical performance, especially the cycling stability of LDH‐based electrodes for high‐performance supercapacitors.

3D Printing of Integrated Metallic Reactor Catalysts: Concept and Application

AbstractSelective laser melting can be used to create custom‐made monolith reactor components with embedded microscale catalytic sites. Doping with noble metals (0.01–0.04 % of Pt, Ir, Ru, or Rh) gave clean incorporation of the active metal particles metals. Yet catalytic activity was low, due to distribution of the active particles between the surface and the bulk of the monolith. Switching to cobalt enabled doping in higher amounts (1.5–2.0 %) with corresponding increase in activity. Using borohydride hydrolysis as a test reaction, we showed that a combined stainless steel and cobalt monolith was active in both batch and continuous systems, for at least 48 h, albeit with some loss of active material. The advantages and limitations of this catalyst/reactor preparation method are discussed.

Emerging Vanadium-Doped Cobalt Chloride Carbonate Hydroxide for Flexible Electrochromic Micro-Supercapacitor: Charged-State Prediction from RGB Input by ANN Model.

Multifunctional devices integrated with electrochromic and supercapacitance properties are fascinating because of their extensive usage in modern electronic applications. In this work, vanadium-doped cobalt chloride carbonate hydroxide hydrate nanostructures (V-C3H NSs) are successfully synthesized and show unique electrochromic and supercapacitor properties. The V-C3H NSs material exhibits a high specific capacitance of 1219.9Fg-1 at 1mVs-1 with a capacitance retention of 100% over 30000 CV cycles. The electrochromic performance of the V-C3H NSs material is confirmed through in situ spectroelectrochemical measurements, where the switching time, coloration efficiency (CE), and optical modulation (∆T) are found to be 15.7 and 18.8s, 65.85cm2C-1 and 69%, respectively. A coupled multilayer artificial neural network (ANN) model is framed to predict potential and current from red (R), green (G), and blue (B) color values. The optimized V-C3H NSs are used as the active materials in the fabrication of flexible/wearable electrochromic micro-supercapacitor devices (FEMSDs) through a cost-effective mask-assisted vacuum filtration method. The fabricated FEMSD exhibits an areal capacitance of 47.15mFcm-2 at 1mVs-1 and offers a maximum areal energy and power density of 104.78Whcm-2 and 0.04mWcm-2, respectively. This material's interesting energy storage and electrochromic properties are promising in multifunctional electrochromic energy storage applications.

Developing cellulose-based hydrophobic/hydrophilic composites for efficient adsorption of oils and heavy metals from water

The oily wastewater and heavy metal ions have been increasingly discharged into water environment, posting a serious threat to ecosystems and human health. However, it remains challenging to use single separation technology to effectively remove oil and heavy metal ions in oil-water mixtures simultaneously. Herein, novel hydrophobic/hydrophilic composites (HHC) were successfully prepared by using A4 paper-derived hydrophilic cellulose as the modified matrix, modifying the polydopamine layer and in-situ growth nanoscale zero-valent iron as active adsorption materials, combined with oleic acid-modified hydrophobic magnetic hollow carbon microspheres, which were used to efficiently and rapidly adsorb heavy metals and oil in oil-water mixtures. Under the optimal adsorption conditions, the adsorption amounts of As(III), As(V), Pb(II) and Cu(II) were 289.6 mg/g, 341.9 mg/g, 241.2 mg/g and 277.5 mg/g, respectively, and the mass transfer rate of HHC to the target ions is fast. The HHC have efficient separation performance for layered oil-water mixtures and emulsified oil-water mixtures, with separation efficiency of 97 % and 92 %. At the same time, due to the abundant adsorption sites, the HHC also exhibit splendid regeneration performance for the four ions after multiple adsorption utilization. Our work designed a approach to achieving promising oil and heavy metal adsorbents with higher adsorption capacity and better regenerative properties.