Core-shell Precursor Research Articles

Electrochemical Synthesis of Hollow Nanoparticles via Anodic Transformation of Metastable Core-Shell Precursors.

Recent advances in electrosynthesis of nanomaterials expanded structural and compositional variations accessible by the electrochemical method; however, reliably synthesizable morphological variety fall shy of that available by conventional solvothermal synthesis. In this communication, electrochemical preparation of surfactant-free hollow nanoparticles is demonstrated. By anodic conversion of core-shell precursors with metastable cores, hollowed nickel nanoparticles with uniform dimensions were synthesized and characterized. Implementation of TEM grids as the working electrodes, identical location tracking of the morphological evolution of single particles to anodic stimulus has been demonstrated. The synthesized nanoparticles were employed as catalysts for the alkaline hydrogen evolution reaction and exhibited catalytic rates that compare favorably to the Pt/C benchmark. This marks the first pure electrochemical synthesis of hollow nanoparticles and shall contribute to the structural diversification of electrosynthesized nanomaterials.

Electrospinning Nonspinnable Sols to Ceramic Fibers and Springs.

Electrospinning has been applied to produce ceramic fibers using sol gel-based spinning solutions consisting of ceramic precursors, a solvent, and a polymer to control the viscosity of the solution. However, the addition of polymers to the spinning solution makes the process more complex, increases the processing time, and results in porous mechanically weak ceramic fibers. Herein, we develop a coelectrospinning technique, where a nonspinnable sol (<10 mPa s) consisting of only the ceramic precursor(s) and solvent(s) is encapsulated inside a polymeric shell, forming core-shell precursor fibers that are further calcined into ceramic fibers with reduced porosity, decreased surface defects, uniform crystal packing, and controlled diameters. We demonstrate the versatility of this method by applying it to a series of nonspinnable sols and creating high-quality ceramic fibers containing TiO2, ZrO2, SiO2, and Al2O3. The polycrystalline TiO2 fibers possess excellent flexibility and a high Young's modulus reaching 54.3 MPa, solving the extreme brittleness problem of the previously reported TiO2 fibers. The single-component ZrO2 fibers exhibit a Young's modulus and toughness of 130.5 MPa and 11.9 KJ/m3, respectively, significantly superior to the counterparts prepared by conventional sol-gel electrospinning. We also report the creation of ceramic fibers in micro- and nanospring morphologies and examine the formation mechanisms using thermomechanical simulations. The fiber assemblies constructed by the helical fibers exhibit a density-normalized toughness of 3.5-5 times that of the straight fibers due to improved fracture strain. This work expands the selection of the electrospinning solution and enables the development of ceramic fibers with more attractive properties.

Fabrication of porous X-shaped Fe3O4@C core-shell structures for tunable microwave absorption

Designing porous materials with low density and high specific surface area is one of the strategies to obtain excellent wave absorbing properties. In this study, the carbon-coated porous X-shaped Fe3O4 composites used as microwave absorption materials were prepared by heat treatment of FeOOH@Polydopamine (PDA) core-shell precursors. It revealed that the X-shaped Fe3O4 core showed improved magnetic loss in GHz band due to its special shape anisotropy and large specific surface area. In addition, the modification of carbon enabled the Fe3O4 absorbers to have stronger polarization and higher electrical conductivity. The composites exhibited great freedom in performance tunability, allowing for strong absorption (RL<−40 dB) at different frequencies. For composites with thick carbon shell, the reflection loss reached the optimal value of − 64.92 dB at 15.04 GHz at the thickness of 1.75 mm, and the effective bandwidth was up to 4.64 GHz (13.04–17.68 GHz). The impressive performance of the as-prepared Fe3O4 @C core-shell composites was mainly attributed to the complementary behaviors of strong dielectric loss and magnetic loss.

Biocompatible Anisole-Nonlinear PEG Core-Shell Nanogels for High Loading Capacity, Excellent Stability, and Controlled Release of Curcumin.

Curcumin, a nontoxic and cheap natural medicine, has high therapeutic efficacy for many diseases, including diabetes and cancers. Unfortunately, its exceedingly low water-solubility and rapid degradation in the body severely limit its bioavailability. In this work, we prepare a series of biocompatible poly(vinyl anisole)@nonlinear poly(ethylene glycol) (PVAS@PEG) core-shell nanogels with different PEG gel shell thickness to provide high water solubility, good stability, and controllable sustained release of curcumin. The PVAS nanogel core is designed to attract and store curcumin molecules for high drug loading capacity and the hydrophilic nonlinear PEG gel shell is designed to offer water dispersibility and thermo-responsive drug release. The nanogels prepared are monodispersed in a spherical shape with clear core-shell morphology. The size and shell thickness of the nanogels can be easily controlled by changing the core-shell precursor feeding ratios. The optimized PVAS@PEG nanogels display a high curcumin loading capacity of 38.0 wt%. The nanogels can stabilize curcumin from degradation at pH = 7.4 and release it in response to heat within the physiological temperature range. The nanogels can enter cells effectively and exhibit negligible cytotoxicity to both the B16F10 and HL-7702 cells at a concentration up to 2.3 mg/mL. Such designed PVAS@PEG nanogels have great potential to be used for efficient drug delivery.

Preparation of paramagnetic ferroferric oxide-calcined layered double hydroxide core–shell adsorbent for selective removal of anionic pollutants

Adsorption is one of the most common methods of pollution treatment. The selectivity for pollutants and recyclability of adsorbents are crucial to reduce the treatment cost. Layered double hydroxide (LDH) materials are one type of adsorbent with poor recyclability. Prussian blue (PB) is a sturdy and inexpensive metal–organic framework material that can be used as the precursor for synthesizing paramagnetic ferroferric oxide (Fe3O4). It is intriguing to build some reusable adsorbents with magnetic separation by integrating LDH and PB. In this work, paramagnetic Fe3O4-calcined LDH (Fe3O4@cLDH) core–shell adsorbent was designed and prepared by the calcination of PB-ZnAl layered double hydroxide (PB@LDH) core–shell precursor, which exhibits high anionic dyes selectivity in wastewater solutions. The paramagnetism and adsorption capability of Fe3O4@cLDH come from the Fe3O4 core and calcined ZnAl-LDH shell, respectively. Fe3O4@cLDH shows an adsorption capacity of 230 mg g−1 for acid orange and a high selectivity for anionic dyes in cation–anion mixed dye solutions. The regeneration process indicates that the high selectivity for anions is related to the specific hydration recovery process of ZnAl-LDH. The synergistic effect of the paramagnetic Fe3O4 core and calcined ZnAl-LDH shell makes Fe3O4@cLDH an excellent magnetic separation adsorbent with high selectivity to anions.

Architecting “Li-rich Ni-rich” core-shell layered cathodes for high-energy Li-ion batteries

Li-rich or Ni-rich layered oxides are considered ideal cathode materials for high-energy Li-ion batteries (LIBs) owing to their high capacity (> 200 mAh g–1) and low cost. However, both are suffering from severe structural instability upon high-voltage cycling (> 4.5 V). Here, “Li-rich Ni-rich” Li1.08Ni0.9Mn0.1O2 oxides with core-shell architecture are designed and synthesized to improve their high-voltage cyclability. These oxides are determined to be composed of a less reactive “Li-rich Mn-rich” shell and a high-capacity “Li-rich Ni-rich” core. As Li-ions gradually enter into the core-shell precursor during high-temperature lithiation reaction, the interdiffusion of elements across the interphase between the Mn-rich shell and the Ni-rich core successively occurs. Such thermally-driven atomic interdiffusion could lead to a thickness-controllable “Li-rich Mn-rich” shell, which can guarantee an exceptional structural reversibility for the layered “Li-rich Ni-rich” core upon long-term cycling. As a consequence, the optimized core-shell Li1.08Ni0.9Mn0.1O2 achieves a capacity retention of 96% at 0.1 C after 100 cycles in the voltage range of 2.7–4.6 V. These findings might open up a new avenue for rational design of advanced cathode materials for LIBs and beyond.

Controllable synthesis of micro-mesoporous Pd@N-doped carbon derived from ZIF@NiCoLDH for enhanced phenol hydrogenation to cyclohexanone

A hollow nitrogen-doped carbon (CN) material, featuring abundant mesopores and high content of graphitic nitrogen, has been synthesized by annealing of the core-shell precursor composed of zeolitic imidazolate framework-67 as core and layered double hydroxides as shell. The proportion of mesopores and nitrogen species in the CN materials significantly vary with the shell thickness of layered double hydroxides in the core-shell precursor by adjusting the etching amount and etching time of nickel nitrate. The as-prepared Pd@CN-1.4–30 catalyst exhibits superior catalytic performance in the hydrogenation of phenol to cyclohexanone, and its turnover frequency (TOF) value is about ten times higher than Pd@CN obtained without the nickel etching, resulting from the abundant mesopores, high graphitic N content, and easy reduction of palladium species. Moreover, Pd@CN-1.4–30 has good reusability during at least six reaction cycles.

ZIF-8/ZIF-67 derived ZnS@Co-N-C hollow core-shell composite and its application in lithium‑sulfur battery

Lithium‑sulfur batteries are energy conversion devices that possess much higher energy densities than traditional lithium-ion batteries. However, the shuttle effect of the chemical reaction in the positive electrode of lithium‑sulfur batteries significantly reduces their specific capacity and charge retention characteristics. Therefore, we fabricated a novel hollow core-shell structure to serve as a separator modification layer and inhibit the shuttle effect. A ZIF-8/ZIF-67 core-shell precursor was first prepared by a room temperature solution reaction. This precursor was then treated by a vulcanization and calcination process to form the end product, in which ZnS was the core active site and CoN doped carbon nanocages were the outer shell. The discharge capacity and the cycling durability of a lithium‑sulfur battery were significantly improved by coating this novel structure on a polyethylene (PE) separator. Electrochemical measurements and microstructural analysis demonstrated that the unique hollow structure served as a polysulfide reservoir. Moreover, the Co-N-C shell and ZnS core of this structure also chemically interacted with and had a catalytic effect on the polysulfides, which enhanced the cycle and rate performance of the battery. Therefore, the lithium‑sulfur battery prepared using a ZnS@Co-N-C core-shell composite-coated PE separator showed excellent electrochemical performance.

Templated Synthesis of SiO2 Nanotubes for Lithium-Ion Battery Applications: An In Situ (Scanning) Transmission Electron Microscopy Study.

One of the weaknesses of silicon-based batteries is the rapid deterioration of the charge-storage capacity with increasing cycle numbers. Pure silicon anodes tend to suffer from poor cycling ability due to the pulverization of the crystal structure after repeated charge and discharge cycles. In this work, we present the synthesis of a hollow nanostructured SiO2 material for lithium-ion anode applications to counter this drawback. To improve the understanding of the synthesis route, the crucial synthesis step of removing the ZnO template core is shown using an in situ closed gas-cell sample holder for transmission electron microscopy. A direct visual observation of the removal of the ZnO template from the SiO2 shell is yet to be reported in the literature and is a critical step in understanding the mechanism by which these hollow nanostructures form from their core-shell precursors for future electrode material design. Using this unique technique, observation of dynamic phenomena at the individual particle scale is possible with simultaneous heating in a reactive gas environment. The electrochemical benefits of the hollow morphology are demonstrated with exceptional cycling performance, with capacity increasing with subsequent charge-discharge cycles. This demonstrates the criticality of nanostructured battery materials for the development of next-generation Li+-ion batteries.

Highly active Ni/Al2O3 catalyst for CO2 methanation by the decomposition of Ni-MOF@Al2O3 precursor via cold plasma

In this work, a novel Ni/Al2O3-P catalyst for CO2 methanation was prepared via an oxygen plasma decomposition of the Ni-MOF@Al2O3 core–shell precursor. The obtained catalyst showed a higher Ni dispersion (26.5%) and contained less NiAl2O4 spinel when compared with the Ni/Al2O3 prepared by the traditional method. The Ni/Al2O3-P catalyst showed significantly enhanced efficiency toward CO2 methanation as compared with those catalysts with a similar nickel loading but are prepared using the traditional method. For example, the space time yield of methane (STYCH4) of the Ni/Al2O3-P catalyst was as high as 21103.6 mg∙gNi-1∙h−1 at 400 °C and GHSV as 12000 ml∙g−1∙h−1, which is 3.4 times higher than that of the reported catalyst (6190.5 mg∙gNi-1∙h−1) with a similar nickel loading under similar reaction conditions. Moreover, Density Functional Theory (DFT) studies together with the CO2-TPD results revealed that both nickel surface and Ni-Al2O3 interface could activate CO2, while the NiAl2O4 surface could not.

MOF-on-MOF nanoarchitectures for selectively functionalized nitrogen-doped carbon-graphitic carbon/carbon nanotubes heterostructure with high capacitive deionization performance

Carbon-carbon heterostructures are an emerging material paradigm to promote the development of capacitive deionization (CDI). The synthesis of this heterostructure with designed functionalities derived from metal-organic frameworks (MOFs) is interesting, but it has always been challenging. We develop MOF-on-MOF nanoarchitectures to obtain a selectively functionalized nitrogen-doped carbon@graphitic carbon/carbon nanotubes heterostructure (NC@GC/CNTs) via the direct pyrolysis of elaborately designed ZIF-L@ZIF-67 core-shell precursors. In this core-shell nanoarchitecture, the inner Zn-based ZIF-L provides a well-defined 2D interface for the oriented growth of the Co-based ZIF-67 outer layer, which will then convert to NC nanosheets with a high nitrogen doping content and large specific surface area for the accommodation of more ions. Meanwhile, the outer ZIF-67 layer creates highly graphitized GC/CNTs architecture offering fast electron transfer and good chemical stability, and it addresses the possible aggregation or collapse of the inner ZIF-L precursors during pyrolysis. As expected, the newly developed NC@GC/CNTs material with well-designed functionalities exhibits high salt adsorption capacity, rapid salt adsorption rate, and excellent CDI cycling stability, which highlight the significance of the carbon–carbon heterostructure to potential CDI applications and the importance of MOF-on-MOF nanoarchitectures on nanomaterials synthetic chemistry.

Realizing Toluene Deep Mineralization by Coupling Nonthermal Plasma and Nitrogen-Enriched Hollow Hybrid Carbon

Achieving excellent efficiency to mineralize volatile organic compounds (VOCs) under nonthermal plasma catalysis (NTP-catalysis) systems tremendously relies on the catalyst design. Herein, we report a dual-template strategy for synthesizing a core-shell structured nitrogen-enriched hollow hybrid carbon (N-HHC) by a facile pyrolysis of a Mn-ZIF-8@polydopamine core-shell precursor. N-HHC exhibits a remarkable plasma synergy effect and superior degradation efficiency for toluene (up to 90% with a specific input energy of 281 J/L), excellent CO2 selectivity (>45%), and byproduct-inhibiting capability. Such outstanding functionality of the developed N-HHC is uniquely attributed to its hollow multistage and channeling structure, high concentration of O3-decomposing species (pyrrolic and oxide pyridinic-N), and abundant ZnO active sites. Shedding light on an efficient synthetic strategy for designing an advanced nanocatalyst with enhanced VOC destruction in the NTP-catalysis system, the present results could be extended to design other N-doped metal/metal oxide-decorated hollow porous carbons for environment-related applications.

Underlying core-shell colloidal nanostructure for Beta zeolite membrane formation

Optimal design of Beta zeolite membrane of a three-dimensional 12-ring interconnected channel system can be vital for environmentally sustainable industrial separation application. A faster route of crystal growth from colloidal solution resulted to formation of poly (nanocrystalline) zeolite Beta membrane. The present SANS study probed the underlying functional diversity of core-shell precursor nanoparticle depending on form and structure factor towards the crystal growth for Beta membrane formation. The data clearly distinguished nanoscale structural arrangements of the synthesis solution before the hydrothermal heat treatment, during the induction and nucleation periods. Initially, shells consisting of organic template, reactive Al species and other dissolved ions surrounded the colloidal silica nanoparticles. Some of the silica cores sizes reduced while the shell thicknesses increased resulting to a heterogeneous colloidal solution system consisting of particles of different core-shell dimensions. The evolution of extra-small core and extra-large shell in the heterogeneous system may be nucleating particles as confirmed by XRD pattern corresponding of zeolite Beta. Deposition of such nucleating particles over the support might led to the formation of Beta zeolite membrane. The SANS profile of the solutions further showed that the nucleating particles were more readily deposited over the zeolite-seeded support than the non-seeded support.

An Evaluation of a Systematic Series of Cobalt-Free Ni-Rich Core-Shell Materials as Positive Electrode Materials for Li-Ion Batteries

A wide range of Co-free Ni-rich core–shell precursors with different core/shell compositions, core sizes and shell thicknesses heated at various temperatures were evaluated in this work. In all cases, the shell phase had a larger Mn content than the core phase. The heating temperature of the precursor/lithium hydroxide mixture during synthesis must be carefully selected. Core–shell materials made at insufficient temperature have low specific capacity due to low crystallinity and a high percentage of Ni atoms in the Li layer. Materials made at excessive temperature show interdiffusion between the shell and core compositions leading to poor capacity retention and poor safety performance. When the heating temperature is selected appropriately, materials which retain the core–shell structure after synthesis can be made. Two of these materials show excellent specific capacity, capacity retention and safety performance. Accelerating rate calorimetry experiments show that charged core–shell materials with a thick and Mn-rich shell have the least reactivity with electrolyte at elevated temperatures, suggesting such materials will lead to the safest Li-ion cells.

Fabrication and mechanical properties of WC nanoparticle dispersion-strengthened copper

Cu composites strengthened through carbide nanoparticle dispersions (CDS–Cu) usually present a problematic agglomeration of nanoparticles that deteriorate their mechanical properties. To address this issue, in this study, CDS–Cu composites were prepared via spark plasma sintering (SPS) of reduced Cu-coated WC core–shell precursor powders, which were obtained through intermittent electrodeposition. This novel preparation method overcomes the aggregation problem of tungsten carbide (WC) nanoparticles, thereby improving the interface-bonding strength between the reinforcing-phase WC nanoparticles and the Cu matrix and further enhancing the load-transfer efficiency. The yield strength of the Cu-2.1 wt% WC composite prepared via pressureless sintering is up to 243 ± 3 MPa, which is significantly higher than that of pure Cu (130 MPa). Orowan strengthening and grain refinement strengthening induced by dispersed nano-WC particles are the main strengthening mechanisms. Due to the load-transfer strengthening, the yield strength of the SPS composite is improved to 271 ± 2 MPa. After hot rolling, the yield strength is further increased to 315 ± 2 MPa, owing to the additional contribution of dislocation strengthening originating from the plastic deformation process. The proposed method in this study provides an advanced pathway for the preparation of ceramic nanoparticle dispersion-strengthened metals.

Hollow carbon nanocages toward long cycle lifespan lithium/sodium-ion half/full batteries

• The structure of HCN can be controlled by the carbonization temperature. • HCN-800 shows an ultra-long cycle life and excellent electrochemical performance. • Achieved high areal mass loading through 3D printing technology. • LiCo 2 O 4 ||HCN-800 and Na 3 V 2 (PO 4 ) 3 ||HCN-800 full cells exhibits a stable cycle. Hollow nanostructures have shown great potential in energy storage and have attracted widespread attention. Here, we report a series of hollow carbon nanocage (HCN) by carbonizing ZIF-8@ZIF-67 core–shell precursor at different temperatures. The study found that when the carbonization temperature is 800 °C, HCN-800 has a good hollow structure, thin shell and large specific surface area, and contains abundant micropores and mesopores. When used as an anode material, even at a current density of 10.0 A g −1 , it can still obtain reversible capacities of 236.1 mA h g −1 (5000 cycles, lithium ion batteries LIBs) and 111.7 mA h g −1 (10000 cycles, sodium ion batteries SIBs), showing excellent cycle stability and long cycle lifespan. And this outstanding ability can still be maintained under high areal mass loading. In addition, the lithium/sodium storage behavior was analyzed by CV kinetic analysis, ex-situ XPS and Raman tests. Benefiting from these advantages, HCN-800 can be prepared with higher areal mass loading by 3D printing and exhibit excellent lithium/sodium storage performance, which will bring broad application prospects for the development of high energy density secondary batteries. Finally, by using LiCoO 2 /Na 3 V 2 (PO 4 ) 3 cathode and HCN-800 anode to assemble a full cell to study the cycle performance. After 100 cycles at 0.1 A g −1 current density, the reversible capacity of 561.5 mA h g −1 (LIBs) and 164.7 mA h g −1 (SIBs) can be provided respectively, indicates that it has the potential of practical application.

Dielectric control of ultralight hollow porous carbon spheres and excellent microwave absorbing properties

Carbon materials have the potential to be excellent absorbing materials due to their lighter weight, easy-to-control graphitization degree and good dielectric properties. However, a single carbon material is often difficult to achieve the ideal electromagnetic wave attenuation effect due to the imbalance of impedance matching and the lack of magnetic loss. In this work, a simple solgel method was used to control the hydrolysis reaction of tetraethyl orthosilicate and the synthesis reaction of phenolic resin to prepare the core–shell precursor of silica coated with phenolic resin/silica spheres. After high-temperature calcination and pickling etching, hollow carbon spheres (HPC) with porous structure were obtained. By adjusting the calcination temperature, the crystallinity and dielectric properties of HPC can be easily adjusted. With an ultra-low filling ratio of 5 wt%, HPC can obtain a wide-band effective microwave absorbing performance of 5.73 GHz (2–18 GHz band) under an ultra-thin thickness of 2.0 mm, which is an excellent absorbing agent with lightweight, thin thickness, strong absorbing ability and wide absorbing band. Considering the simple preparation scheme, HPC is expected to become one of the candidates for high-efficiency microwave absorbers. The special hollow, porous structure and suitable degree of graphitization are the main reasons for the effective wave absorption of HPC.

Iron Based Core-Shell Structures as Versatile Materials: Magnetic Support and Solid Catalyst

Core-shell materials are promising functional materials for fundamental research and industrial application, as their properties can be adapted for specific applications. In particular, particles featuring iron or iron oxide as core material are relevant since they combine magnetic and catalytic properties. The addition of an SiO2 shell around the core particles introduces additional design aspects, such as a pore structure and surface functionalization. Herein, we describe the synthesis and application of iron-based core-shell nanoparticles for two different fields of research that is heterogeneous catalysis and water purification. The iron-based core shell materials were characterized by transmission electron microscopy, as well as N2-physisorption, X-ray diffraction, and vibrating-sample magnetometer measurements in order to correlate their properties with the performance in the target applications. Investigations of these materials in CO2 hydrogenation and water purification show their versatility and applicability in different fields of research and application, after suitable individual functionalization of the core-shell precursor. For design and application of magnetically separable particles, the SiO2 shell is surface-functionalized with an ionic liquid in order to bind water pollutants selectively. The core requires no functionalization, as it provides suitable magnetic properties in the as-made state. For catalytic application in synthesis gas reactions, the SiO2-stabilized core nanoparticles are reductively functionalized to provide the catalytically active metallic iron sites. Therefore, Fe@SiO2 core-shell nanostructures are shown to provide platform materials for various fields of application, after a specific functionalization.

Impact of Shell Composition, Thickness and Heating Temperature on the Performance of Nickel-Rich Cobalt-Free Core-Shell Materials

Ni-rich lithium transition metal oxides have high specific capacity but generally have inferior cycling performance compared to their lower Ni content counterparts. core–shell structures with a Ni-rich core and a Mn-containing shell have been reported to improve the cycling performance of Ni-rich materials, but the impact of the shell on the performance of core–shell materials needs to be elaborated more. In this work, three core–shell precursors having a Ni(OH)2 core, but different shell compositions and thicknesses, were lithiated at various temperatures and the resulting materials were examined physically and electrochemically. They were compared to the corresponding uniform “shell” materials lithiated at the same temperatures. The selection of heating temperature is crucial and must be made with care to limit the interdiffusion between core and shell compositions while still heating to sufficient temperature to prepare crystalline materials with little lithium in the transition metal layer. Once these factors are understood, core–shell structures with an optimized shell thickness and Mn content can be made to simultaneously achieve high specific capacity and long cycle life.

Atomic Co/Ni active sites assisted MOF-derived rich nitrogen-doped carbon hollow nanocages for enhanced lithium storage

• Atomic Co/Ni bimetallic active sites anchoring on MOFs-derived N-doped super carbon is precisely devised. • Super Li affinity coupling with catalytic effect endows the anode materials enhanced lithium storage performance. • The theoretical calculation further confirms the superior affinity of the Li on atomic Co/Ni active sties. Herein, a robust MOFs-derived super-carbon embedding with single atom Co/Ni anode materials for LIBs is developed by one-step annealing of the core–shell precursor ZIF-8@ZIF-67 with the introduction of dimethylglyoxime nickel as Ni source. The characterization results clearly indicate that atomic Co/Ni active sites accompanied with suitable CoNi nanoparticles are evenly embedded in the MOF-derived hollow rich-nitrogen carbon matrix. Simultaneously, moderate short carbon nanotubes root in polyhedral surface under the catalytic effect from the CoNi nanoparticles and construct an advanced conductive network. As a result, it delivers a high reversible lithium-ion storage capacity of 462.1 mAh g −1 at a current density of 0.5 A g −1 over 500 cycles, excellent rate performance of 223.28 mAh g −1 even at a high current density of 2 A g −1 , which is much higher than most of reported carbon-based electrode materials. The enhanced lithium storage performance mainly derives from the moderate affinity of the Li by the atomic Co/Ni active sites incorporated with their powerful catalytic effect assisting MOF-derived rich-N doped carbon base. Moreover, the superior nano-structure of the hollow rich-nitrogen carbon skeleton with in-situ grown short carbon nanotubes improves the conductivity of electrode materials, relieves the volume expansion and accelerates the migration rate of lithium ions and electrons. The theoretical calculation further confirms the superior affinity of the Li on atomic Co/Ni active sties.