Conductive Carbon Framework Research Articles

Porous activated carbon integrated carbon nitride nanosheets as functionalized separators for the efficient polysulfide entrapment in Li[sbnd]S batteries

Electrification of vehicles, hybrid aircraft and the advancement of portable electronics are exacting the deployment of high energy-dense batteries. The high theoretical capacity of sulfur (1675 mAh g−1), cost-effectiveness and environmental benignity of the lithium‑sulfur batteries (LSBs) are propitious for electrochemical energy storage beyond Li-ion battery technology. In this work, we described a simple, scalable preparation and electrochemical performance of porous activated carbon (PC)-infused graphitic carbon nitride (GCN) nanosheets with various ratios (PC@GCN 11, PC@GCN 12 and PC@GCN 21) as a polysulfide anchoring functionalized separator for LSBs. The high specific area (822 m2/g), hetero porosity, conductive carbon framework, surface functionalities and enriched N-doping of the PC@GCN synergistically induce mitigation of polysulfides via chemical and physical adsorption pathways in LSBs. The PC@GCN 21 modified separator demonstrates a high initial discharge capacity of 1389 mAh g−1 at a 0.1C rate and exhibits better capacity retention over 500 cycles at a 1C rate (655 mAh g−1) with sulfur loading of 3.8 mg/cm2 accompanied by high coulombic efficiency (94 %). The assembled cell with high S-loading (5.12 mg/cm2) shows a high initial discharge capacity of 712 mAh g−1 at 0.1C rate conditions. High Li-ion transference number (0.714), stable shuttle current, minimal coulombic efficiency loss (0.84 %), low shuttle factor and negligible self-discharge behaviour support the superior performance of the PC@GCN 21 coated cells. This report demonstrates that combining the high surface area, non-polar porous carbon with polar graphitic carbon nitride is a practical approach for designing metal-free functionalized separators for energy-dense LSBs.

Self-supported porous carbon decorated with coralline RuCo alloy for efficient OER in acid

Developing an OER electrocatalyst that combines high performance with low cost represents a crucial challenge to address for the widespread adoption and implementation of PEM water electrolyzers. The Ru-based catalyst has garnered significant interest owing to its cost-effectiveness and high activity, positioning it as one of the prime contenders to replace Ir-based catalysts. Nevertheless, Ru-based catalysts are easily corrupted by oxidation at high potential, leading to poor catalyst durability. In this work, we used a simple method to synthesize an electrode material which was a carbon framework-supported coralline RuCo alloy catalyst on the CC surface. The porous and highly conductive carbon framework in RuCo@C/CC effectively anchors the RuCo alloy, preventing its aggregation and detachment from the CC. And the carbon framework also facilitates enhanced mass and charge transfer processes, thereby greatly improving catalytic performance. Additionally, charge transfer and redistribution occur within the RuCo alloy, thereby efficiently reducing the activation energy barrier (via the AEM mechanism) of the OER, consequently enhancing OER performance. Therefore, RuCo@C/CC exhibits outstanding performance in acidic OER, achieving a current density of 10 mA/cm2 at a remarkably low overpotential of 200 mV, significantly surpassing commercial RuO2 (which requires 280 mV), owing to its exceptional OER kinetics, while also demonstrating exceptional stability in practical PEMWE test. This research introduces a convenient route for creating a highly efficient and durable alloy electrocatalyst, showcasing its promise for Proton Exchange Membrane Water Electrolysis.

Synthesis of polymeric 2D-graphitic carbon nitride (g-C3N4) nanosheets for sustainable photodegradation of organic pollutants

A superficial, one step thermal polycondensation method has been employed for the manifestation of graphene like graphitic carbon nitride (g-C3N4) catalyst. The as synthesized g-C3N4 was well characterized by SEM and EDAX analysis, XRD, ATR-IR, FTIR, Fluorescence spectroscopy, Raman spectroscopy and UV–Visible spectroscopy which provide structural, morphological assemblage relating to the structure of g-C3N4. The g-C3N4 showed that an outstanding photochemical stability, morphology, conductive carbon framework and superior photocatalytic activity. The band gap value of g-C3N4 is 2.34 eV determined using Tauc plot. Due to low band gap (2.33 eV) and unique morphology which provides high separation and migration ability of the photogenerated charges, the g-C3N4 shows enhanced photocatalytic activity for the removal of many organic dyes such as Rhodamine B (RhB), Crystal Violet (CV), Methylene Blue (MB), Methyl Orange (MO), Naphthol Orange (NO) and a phenol derivative, p-Nitrophenol (p-NP). Among them, RhB dye was degraded almost 81 % at 90 min under sunlight irradiation in presence g-C3N4 while other dyes and p-NP was degraded at lower rate. From the experimental data, it was found that MO and p-NP degradation rate was least. The rate constant for degradation of Rh B is 1.1 × 10−2 min−1. Therefore, g-C3N4 can be used as an efficient photocatalyst for waste water treatment by the removal of such organic pollutants.

Integrated Li3VO4 and boron doped carbon microspheres with high tap density for high-rate and durable lithium storage

As an essential representative of novel anode materials with high capacity and safe voltage, Li3VO4 (LVO) still suffers from the challenges of low electronic conductivity and low tap density of nanostructures. Herein, a strategy of nanoization and recombination is proposed to synthesize the integrated LVO and boron doped carbon microspheres (LVO/BC-MS-550) with high tap density via a chemical crosslink method to improve the Li-ion storage performance. LVO/BC-MS-550 is consisted of the well-dispersed LVO nano-crystals in tightly stacked carbon spheres derived from the cross-linked network of boric acid (BA) and polyvinyl alcohol (PVA). By introducing conductive and continuous carbon framework, the LVO crystals are controlled to grow in the confined region with mitigated volume changes, as well as the enhanced electronic conductivity. Benefiting from the constructive advantages, LVO/BC-MS-550 anode delivers a specific capacity of 512.1 mAh g−1 at the current density of 0.2 A g−1 (0.34 C) after 300 cycles, and ultra-long cycling performance of 231.8 mAh g−1 over 5000 cycles at the charging/discharging current density of 4/2 A g−1, exhibiting rapid pseudo-capacitance reaction kinetics. This work provides valuable insights into the fabrication of in situ three-dimensional crosslinked carbon and LVO composites for alternative grid-scale electrochemical applications.

Structure and Defect Engineering of V3S4-xSex Quantum Dots Confined in a Nitrogen-Doped Carbon Framework for High-Performance Sodium-Ion Storage.

Constructing quantum dot-scale metal sulfides with defects and strongly coupled with carbon is significant for advanced sodium-ion batteries (SIBs). Herein, Se substituted V3S4 quantum dots with anionic defects confined in nitrogen-doped carbon matrix (V3S4-xSex/NC) are fabricated. Introducing element Se into V3S4 crystal expands the interlayer distance of V3S4, and triggers anionic defects, which can facilitate Na+ diffusions and act as active sites for Na+ storage. Meanwhile, the quantum dots tightly encapsulated by conductive carbon framework improve the stability and conductivity of the electrode. Theoretical calculations also unveil that the presence of Se enhances the conductivity and Na+ adsorption ability of V3S4-xSex. These properties contribute to the V3S4-xSex/NC with high specific capacity of 447 mAh g-1 at 0.2 A g-1, and prominent rate and cyclic performance with 504 mAh g-1 after 1000 cycles at 10 A g-1. The sodium-ion hybrid capacitors (SIHCs) with V3S4-xSex/NC anode and activated carbon cathode can achieve high energy/power density (maximum 144 Wh kg-1/5960 W kg-1), capacity retention ratio of 71% after 4000 cycles at 2 A g-1. This work not only synthesizes V3S4-xSex/NC, but also provides a promising opportunity for designing quantum dots and utilizing defects to improve the electrochemical properties.

MoO2-C@MoS2: A unique cocatalyst with LSPR effect for enhanced quasi-full-spectrum photocatalytic hydrogen evolution of CdS

A well-designed cocatalyst structure can improve the light-harvesting and quantum efficiency of photocatalysis. A multidimensional MoO2-C@MoS2 (MOCS) cocatalyst was successfully synthesized by post-sulfidation of MoO2-C nanorods. This controlled sulfidation process effectively inhibits the undesired oxidation of MoO2, stabilizing its metallicity and creating a synergistic effect for H2 evolution. Firstly, the highly dispersed metallic MoO2 nanoparticles induce localized surface plasmon resonance effects, expanding the light-harvesting range and generating abundant hot electrons. Secondly, the build-in electrostatic field and highly conductive carbon framework facilitates efficient interfacial electrons transfer. Thirdly, the amorphous MoOx and fragmented few-layers MoS2 in MOCS provide dual active sites with superior intrinsic activity for H2 evolution. Moreover, the unique multi-interface structure of MOCS optimizes the separation and reaction of charge carriers. As a result, the 20 wt% MOCS/CdS system show an excellent quasi-full-spectrum driven photocatalytic H2 evolution activity of 48.41 mmol/h·g, with 4.03 mmol/h·g in near-infrared region (> 800 nm).

2D Mesoporous Naphthalene‐Based Conductive Heteroarchitectures toward Long‐Life, High‐Capacity Zinc‐Iodine Batteries

AbstractNowadays, rechargeable aqueous zinc‐iodine batteries have attracted extensive attention due to their low cost, high safety, and high theoretical capacity. However, the poor electrical conductivity of iodine and the shuttling effect of soluble polyiodide ions impose an insurmountable constraint on their performance. Here, a facile soft‐hard‐templated co‐assembly strategy is proposed to fabricate naphthalene‐based heteroarchitectured conductive nanosheets with ordered mesopore arrays (≈10 nm), uniform thickness (24.5 nm), high specific surface area (221.5 m2 g−1), and good electronic conductivity (3.9 × 10−3 S cm−1). Density function theory calculation and systematic experimental results show that the complementary combination of the 2D polar semiconducting polymer chains and conductive carbon framework enables the highly efficient immobilization of iodine and then constrains their shuttling effect through strong physicochemical interactions. Accordingly, the resultant zinc‐iodine batteries deliver a high specific capacity of 271.4 mAh g−1, excellent rate capability, and impressive long‐term cycling stability (35 000 cycles at a high current density of 10 A g−1), superior to most of the previous reports. This study opens new venues for rationally constructing heteroarchitectured porous materials for energy storage applications.

Embedding nickel diselenide in carbon derived from biomass and its electrocatalytic activity for hydrogen evolution reaction

Electrolysis of water can generate green hydrogen as a sustainable energy resource, which mitigates the impacts of climate change caused by burning fossil fuels and excessive carbon emissions. Cheap and abundant transition metal compounds are emerging as promising candidates to replace noble metal catalysts. Yet their poor conductivity is a critical challenge to obtain a high activity. In this study, we present a facile approach to construct the nanocomposite of NiSe2 embedded on multi-element (N, S) doped carbon derived from biomass. The synthesized electrocatalyst (NiSe2@C) exhibited an active hydrogen evolution electrocatalyst with a low overpotential of 206 mV to obtain a current density of 10 mA cm−2 and a small Tafel slope of 59 mV dec−1. Electrochemical analysis ascribed the high catalytic performance to the synergistic effect of the NiSe2 nanoparticles with large active sites and the superior conductive carbon framework, boosting the charge transfer for hydrogen generation. The findings may lead to new opportunities for enhancing hydrogen generation from electrochemical water splitting using earth-abundant catalysts.

Cr2S3 nanosheet grafted with porous N-doped carbon architecture as an anode with enhanced Li-storage property

Chromium-based transition metal sulfide such as chromium hemi trisulfide (Cr2S3) gradually emerges as a potential lithium-ion host material considering its relatively large specific capacity along with low cost advantage. However, some excruciating issues such as serious particle aggregation, large volume expansion and insufficient inherent conductivity always result in an inferior Li-storage behavior such as low reversible capacity, limited cycling life and poor high-rate performance. Rational structure design and effective combination with suitable component are crucial to achieve superior Li-storage performance. Herein, a heterostructured composite with small Cr2S3 nanosheets embedded into phenanthroline-derived N-doped porous carbon skeleton (Cr2S3/NC) has been synthesized through a calcination and sulfuration route. In as-prepared Cr2S3/NC composite, Cr2S3 nanosheets are well confined by carbon matrix, which is conductive to an effective suppression on aggregation and volume change. Meanwhile, porous conductive carbon framework supplies desirable expressway for fast electron delivery and reduces the distance for lithium ions diffusion. Consequently, the Cr2S3/NC anode delivers a remarkably elevated Li-storage performance.

3D Framework Carbon for High-Performance Zinc-Ion Capacitors.

Given the rapid progress and widespread adoption of advanced energy storage devices, there has been a growing interest in aqueous capacitors that offer non-flammable properties and high safety standards. Consequently, extensive research efforts have been dedicated to investigating zinc anodes and low-cost carbonaceous cathode materials. Despite these efforts, the development of high-performance zinc-ion capacitors (ZICs) still faces challenges, such as limited cycling stability and low energy densities. In this study, we present a novel approach to address these challenges. We introduce a three-dimensional (3D) conductive porous carbon framework cathode combined with zinc anode cells, which exhibit exceptional stability and durability in ZICs. Our experimental results reveal remarkable cycling performance, with a capacity retention of approximately 97.3% and a coulombic efficiency of nearly 100% even after 10,000 charge-discharge cycles. These findings represent significant progress in improving the performance of ZICs.

Hierarchical porous loofah-like carbon with sulfhydryl functionality for electrochemical detection of trace mercury in water

Mercury is a common contaminant found in natural waters, which is highly toxic to human health. Thus, the facile and reliable monitoring of mercury in waters is of great significance. In this study, we fabricated a novel loofah-like hierarchical porous carbon with sulfhydryl functionality (S-LHC), and applied it as an ultrasensitive sensor for the electrochemical detection of mercury in water. The S-LHC was prepared through the direct pyrolysis of a triazole-rich metal-organic framework (MOF), followed by chemical modification using thioglycolic acid. The highly conductive N-doped carbon framework of S-LHC facilitated the electron transfer in mercury electrochemical sensing. Meanwhile, the open hierarchical pore structure and abundant sulfhydryl groups allowed the fast diffusion and effective enrichment of mercury ions. Consequently, the S-LHC sensor exhibited an exceptionally high sensitivity for mercury ions, with the mercury detection limit (0.36 nM) orders of magnitude lower than the regulated values in drinking water (typically 10∼30 nM). The constructed sensor also afforded good anti-interference ability and excellent stability for long-term detection of mercury in a variety of complex real water samples. The present study provides not only a facile method for mercury detection, but also a new idea for the construction of highly sensitive electrochemical sensors.

Hetero‐Packing Nanostructures of Iron (III) Fluoride Nanocomposite Cathode for High‐Rate and Long‐Life Rechargeable Lithium‐Ion Batteries

AbstractHigh‐performance metal fluoride cathodes are crucial to design ultrahigh‐capacity lithium metal batteries for taking part in the next‐generation energy storage market. However, their insulating nature and sluggish reaction kinetics result in voltage hysteresis, low‐rate capability, and rapid capacity degradation. Herein, a generalizable one‐step melt synthesis approach is reported to construct hetero‐packing nanostructures of FeF3@C‐Asphalt nanocomposites, where ultrafine FeF3 nanoparticles are homogeneously covered by a high conductive carbon framework. By the electrochemical kinetics calculation and multiphysics simulations, this FeF3@C‐Asphalt nanocomposites consist of ultrafine nanoparticles and a constrained carbon framework, offering a high tap density (1.8 g cm−3), significantly improved conductivity, and enhanced charge pathways, and thereby enabling the fast electron transport, rapid ion migration, depressed electrode internal stress, and mitigated volume expansion. As a result, the optimized FeF3@C‐Asphalt cathode delivers a high capacity of 517 mAh g−1, high cyclic stability of 87.5% after 1000 cycles under 5 A g−1 (10 C), and excellent capacity retention of 77% from 0.5 A g−1 to 10 A g−1 (20 C, 250 mAh g−1). The work provides an easy‐to‐operate and low‐cost approach to accomplish high cyclic stability metal fluoride‐lithium batteries, which will guide the development of fast‐charging ultrahigh‐capacity cathode materials for the new energy industry.

Pseudohexagonal Nb2O5 Anodes for Fast-Charging Potassium-Ion Batteries

High-rate batteries will play a vital role in future energy storage systems, yet while good progress is being made in the development of high-rate lithium-ion batteries, there is less progress with post-lithium-ion chemistry. In this study, we demonstrate that pseudohexagonal Nb2O5(TT-Nb2O5) can offer a high specific capacity (179 mAh g-1 ∼ 0.3C), good lifetime, and an excellent rate performance (72 mAh g-1 at ∼15C) in potassium-ion batteries (KIBs), when it is composited with a highly conductive carbon framework; this is the first reported investigation of TT-Nb2O5 for KIBs. Specifically, multiwalled carbon nanotubes are strongly tethered to Nb2O5 via glucose-derived carbon (Nb2O5@CNT) by a one-step hydrothermal method, which results in highly conductive and porous needle-like structures. This work therefore offers a route for the scalable production of a viable KIB anode material and hence improves the feasibility of fast-charging KIBs for future applications.

Porous V2O3/C composite electrodes derived from V-MOF with advanced performance for Zn-ion battery

Vanadium oxides are promising cathode materials for Zn-ion batteries. However, they are always suffered from inferior performance because of intrinsic sluggish kinetics, poor conductivity and surface elements dissolution. In this work, porous composite of V2O3 nanoparticles embedded in carbon framework is fabricated by pyrolysis of a Vanadium-base MOF. Attributing to the abundant pores, high specific area and conductive carbon framework, the obtained hierarchical composite delivers a high specific capacity of 240 mAh g−1 at 0.5 A g−1 although the content of carbon is up to 50%, and exhibits a good rate performance with 86.6% retention when the current densities increased from 0.5 to 4 A g−1. Moreover, the cycling performance of the composite is much better than that of commercial V2O3.

Ultrathin manganese oxides enhance the electrocatalytic properties of 3D printed carbon catalysts for electrochemical nitrate reduction to ammonia

Electrochemical nitrate reduction reaction (NO3RR) is a promising approach to remedying the environmental pollution from nitrate, and simultaneously a sustainable alternative to traditional Haber-Bosch process especially for decentralized ammonia production. Here, we firstly explore the electrocatalytic activity of two 3D printed carbon frameworks consisting of 0-dimentional (0D) carbon black and 1-dimentional (1D) carbon nanotubes towards cost-efficient electrocatalysts for NO3RR. Different from the electrocatalytic inert properties of 0D carbon framework, 1D carbon framework exhibits the electrocatalytic activity for NO3RR with a Faradaic efficiency of more than 50% at − 1.21 V vs. RHE. Control experiments suggest that such activity originates from the synergistic electrocatalytic contributions between intrinsic surface features of carbon nanotubes and metallic impurities. Since the content and distribution of these metallic impurities are unpredictable, an ultrathin deposit of electrocatalytic manganese oxides is further deposited by atomic layer deposition on 1D carbon framework to ensure well defined surfaces for effective NO3RR. The proposed strategy by integrating 3D printing of conductive carbon framework with atomic layer deposition of an electrocatalytic layer provides a feasible electrode fabrication for electrochemical NO3RR and shows a promising prospect in the electrocatalytic field.

Vanadium nitride nanocrystals decorated ultrathin, N-rich and hierarchically porous carbon nanosheets as superior polysulfides mediator for stable lithium-sulfur batteries

The diligent exploitation of high-efficiency polysulfides mediators have exhibited enormous prospects to promote the cycling performance of lithium-sulfur (Li–S) batteries with desirable sulfur loading and high sulfur utilization efficiency. Herein, we craft an elaborated catalyst of ultrafine vanadium nitride nanocrystals confined hierarchically porous, ultrathin nitrogen-doped carbon nanosheets (denoted as VN@NC) via a simple approach. Owing to the highly conductive porous carbon framework integrated with enriched V–N–C active sites, well-heterostructured VN@NC can actively favor the entrapping–adsorption–catalytic conversion of the polysulfides intermediates for boosted surface redox kinetics. As the separator interlayer, VN@NC dedicates to high-performance Li–S batteries with high discharge capacities (1594.8 mAh g−1 at 0.1 C), excellent rate capabilities (766.5 mAh g−1 at 5.0 C) and exceptional cyclic durability by a slight decay of 0.067% per cycle upon 500 cycles at 1.0 C. Interestingly, two cycled Li–S batteries after 100 cycles at 0.5 C can be connected to charge a daily smartphone. Even under elevated sulfur loading of 4.5 mg cm−2 and lean electrolyte of 8 μL mg−1, the assembled Li–S battery still maintains a stable cycling performance. The cost-effective VN@NC catalyst could offer a viable avenue to construct applicable sulfur catalysts for advanced Li–S batteries.

Three-dimensional carbon foam decorated with SnO2 as multifunctional host for lithium sulfur batteries.

Lithium-sulfur (Li-S) batteries with high theoretical capacity and abundant sulfur resources are potential energy storage systems. Nevertheless, there are several roadblocks that strongly limit the commercial application of Li-S batteries, including the insulating nature of sulfur and Li2S, large volume change and the shuttle effect of lithium polysulfides. Herein, a three-dimensional carbon foam (CF) decorated with SnO2 (SnO2/CF) is fabricated by the simple electrodeposition and used as a sulfur host to resolve the bottleneck issues in Li-S batteries. Thanks to the synergetic effect of the polar SnO2 and conductive carbon framework, the SnO2/CF framework is endowed with multifunctionalities such as providing three-dimensional conductive framework, inhibiting the migration of polysulfides and improved reaction kinetics. Consequently, durable cycle performance with a capacity of 458.2 mAh g-1 after 1000 cycles at 1 C is achieved. Furthermore, a high capacity of 749.5 mAh g-1 at a high rate of 5 C is attained. Remarkably, under high sulfur loading of 8.84mgcm-2, the S@SnO2/CF cathode can still deliver a high specific capacity of 389.8 mAh g-1 after 300 cycles at 0.5 C. This work demonstrates a novel strategy to improve the performance of Li-S batteries for energy storage applications.

Asymmetric N-coordinated iron single-atom catalysts supported on graphitic carbon for polysulfide conversion in lithium-sulfur batteries

Lithium-sulfur (Li-S) batteries with extremely high theoretical energy density are expected to be the next-generation energy storage systems. However, the electrochemical performance of Li-S batteries is still restricted by the shuttle effect of lithium polysulfides (LiPSs) resulting from their sluggish conversion kinetics. Herein, we demonstrated a coordination-confinement-pyrolysis strategy to fabricate iron single-atom catalysts (Fe SACs) supported on graphitic carbon nanocapsules (GCNC) by using imine (-RC = N-)-enriched polymer as precursors, aiming at suppressing the shuttle effect in Li-S batteries via simultaneously enhancing LiPSs confinement and catalytic conversion. The in-depth experiment investigations have revealed that the as-obtained N-doped carbon nanocapsules with ample hollow channels and large specific surface area (SSA) enable efficient adsorption and confinement for LiPS intermediates. Further, the isolated Fe SACs anchored on highly conductive graphitic carbon frameworks show an asymmetric N-coordinated active moiety (Fe-N5) that ensures fast redox kinetics of LiPSs and solid Li2S/Li2S2 products. As a result, the Li-S cell with a functional separator modified by the Fe-N5/GCNC exhibits a much-increased specific capacity of 1125 mAh/g at 0.1 C, excellent rate capability of 627 mAh/g at 2 C, and remarkable long-term cycling stability with a low capacity decay of 0.0386 % per cycle upon 1000 cycles. This work presents a useful strategy to fabricate high-activity SACs coupled with hollow graphitic carbon frameworks and to accelerate the catalytic conversion kinetics of LiPS intermediates for high-performance Li-S batteries.

Self-supported hollow-Co3O4@CNT: A versatile anode and cathode host material for high-performance lithium-ion and lithium-sulfur batteries

Inferior specific capacity and sluggish redox kinetics are the most stubborn problems lithium-ion and lithium-sulfur batteries (LIBs and LSBs) are facing, respectively. Here we report a facile fabrication of self-supported hollow Co 3 O 4 @carbon nanotubes on carbon cloth (H-Co 3 O 4 @CNT/CC) through a mild pyrolysis-oxidation process. The additive- and binder-free H-Co 3 O 4 @CNT/CC shows excellent electrochemical performances as both LIBs and LSBs electrodes. As a robust integrated anode for LIBs, the areal capacities are 2.72 mAh cm −2 at the current density of 0.5 C over 1000 cycles. While as a durable cathode host for LSBs, favorable areal capacities of 2.37 mAh cm −2 are maintained with a low capacity decay of 0.11 % per cycle at the sulfur loading of 6 mg cm −2 and current density of 1 C after 400 cycles. Electrochemical technology, ex situ Raman spectroscopy and DFT calculations are performed to comprehensively analyze H-Co 3 O 4 @CNT/CC via thermodynamics and kinetics. It is demonstrated that the hierarchically hollow interior structure, strong adsorb ability of Co 3 O 4 toward polysulfides and three-dimensional (3D) inter-connected conductive carbon framework are responsible for the high areal capacity, fast redox kinetics and cycling durability. The synergistic effect of different components and structures of hollow-Co 3 O 4 @CNT, which have internal hollow structure, incorporation of Co 3 O 4 into elastic buffering framework and high porosity, contributes greatly to the superior electrochemical performances in terms of high areal capacity, good rate capability and ultralong cycling stability. • The integrated electrode possesses the merits of hollow nanostructured Co 3 O 4 and 3D inter-connected conductive network. • Electrochemical technology and DFT calculations are performed to comprehensively analyze H-Co 3 O 4 @CNT/CC. • H-Co 3 O 4 @CNT/CC delivers high areal capacities of 2.72 mAh cm -2 after 1000 cycles at 0.5 C as anode.

Hollow Porous N and Co Dual-Doped Silicon@Carbon Nanocube Derived by ZnCo-Bimetallic Metal-Organic Framework toward Advanced Lithium-Ion Battery Anodes.

Silicon (Si) has been recognized as a promising alternative to graphite anode materials for advanced lithium-ion batteries (LIBs) owing to its superior theoretical capacity and low discharge voltage. However, Si-based anodes undergo structural pulverization during cycling due to the large volume expansion (ca. 300-400%) and continuous formation of an unstable solid electrolyte interphase (SEI), resulting in fast capacity fading. To address this challenge, a series of different amounts of silicon nanoparticles (Si NPs)-encapsulated hollow porous N-doped/Co-incorporated carbon nanocubes (denoted as p-CoNC@SiX, where X = 50, 80, and 100) as anode materials for LIBs are reported in this paper. These hollow nanocubic materials were derived by facile annealing of different contents of Si NPs-encapsulated Zn/Co-bimetallic zeolitic imidazolate frameworks (ZIF@Si) as self-sacrificial templates. Owing to the advantages of well-defined hollow framework clusters and highly conductive hollow carbon frameworks, the hollow porous p-CoNC@SiX significantly improved the electronic conductivity and Li+ diffusion coefficient by an order of magnitude higher than that of Si NPs. The as-prepared p-CoNC@Si80 with 80 wt % Si NPs delivered a continuously increasing specific capacity of 1008 mAh g-1 at 500 mA g-1 over 500 cycles, excellent reversible capacity (∼1361 mAh g-1 at 0.1 A g-1), and superior rate capability (∼603 mAh g-1 at 3 A g-1) along with an unprecedented long-life cyclic stability of ∼1218 mAh g-1 at 1 A g-1 over 1000 cycles caused by low volume expansion (9.92%) and suppressed SEI side reactions. These findings provide new insights into the development of highly reversible Si-based anode materials for advanced LIBs.