Hierarchical Porous Nanostructures Research Articles

MnO2-decorated flexible carbon nanofibers with controllable hierarchical porous nanostructures for high energy density supercapacitors

Constructing hierarchical porous structures and reducing material size enhance the electrochemical efficiency of porous carbon-based electrodes. In this study, ultrafine hierarchical porous carbon-based nanofibers were synthesized via electrospinning a blend of polyacrylonitrile, polymethyl methacrylate (PMMA), and zinc acetate dihydrate (ZAH), followed by pre-oxidation, carbonization, and acid washing. Adjusting the ZAH content allowed precise control of fiber diameters (300-600nm) and promoted significant hierarchical porous structures, achieving an optimal mesopore to micropore ratio (1.65) and a high specific surface area (SSA) of 599 m²/g. MnO2 nanosheets were in-situ modified on the carbon nanofibers, forming a hybrid electrode (MnO2@HPCNFs) with excellent flexibility, high SSA value, and rich pore structure. This electrode demonstrated a specific capacitance value equal to 1035 F/g at 0.5 A/g and maintained 80.7% capacitance at 10 A/g. The assembled asymmetric supercapacitor achieved an energy density of 54.81 Wh/kg. This study presents new possibilities for binder-free, self-supporting electrodes in electrochemical energy storage devices.

Biotemplate synthesis of SnO2 hollow porous structures for enhanced isopropanol sensing performance

Researchers are showing significant interest in the development of nanostructures with hierarchical porosity. This study introduces an eco-friendly, cost-effective, and straightforward method to create SnO2 hollow porous nanostructures using the peony as a biotemplate. A comprehensive analysis of the gas sensing characteristics of these hierarchical SnO2 hollow porous nanostructures is conducted. The results show that the gas sensor based on SnO2 showcases relatively high response values measuring 18.3 and exhibits rapid response speed of 1 s to 100 ppm isopropanol, even at a comparably low operating temperature of 180 °C. Additionally, the sensor displays good repeatability and long-term stability, which can be attributed to the inherent advantages stemming from its distinct structure. Therefore, this study provides experimental and theoretical foundations for the potential application of hollow porous SnO2 structures in sensor technology.

Novel three-dimensional architectured ZnMgAl ternary layered double hydroxide@reduced graphene oxide nanocomposites as electrode material for high-performance supercapacitor

Ternary layered double hydroxides (LDH) have recently attracted immense attention owing to their stupendous features, such as fine compositional tuning, multiple valence states, and superior electrochemical activity. Moreover, their intriguing structures and distinctive physiochemical properties delineate them as an exemplary material to serve as electrodes for high-performance supercapacitors (SCs). The present work reports the in-situ synthesis of Zinc Magnesium Aluminium LDH (ZMA) integrated with reduced graphene oxide (rGO) through a single-step hydrothermal approach. The resulting novel ternary ZMA@rGO nanocomposite (ZMAG) possesses a unique architecture incorporating hierarchical 3D nanoflowers of ZMA embedded on graphene nanosheets. The porous morphology of LDH improves interfacial charge transport, which results in more faradaic reactions at the electrochemically active sites. In addition, the conductive graphene nanosheets render a high specific surface area, endowing excellent capacitive behavior. The amalgamated electrochemical properties of ZMA and rGO develop a competent electrode material (ZMAG) for SCs. The ZMAG2 nanocomposite having ZMA and rGO in 1:1, evinces a specific capacitance (Cs) of 656.7 F/g at a current density (Id) of 1 A/g. Furthermore, the asymmetric supercapacitor (ASC) features admirable cycle stability (retains 89% of initial capacitance after 15,000 charge/discharge cycles). Herein, the real-time application of ZMA@rGO//AC ASC has also been demonstrated. Therefore, hierarchical porous nanostructure proclaims new prospects for fabricating proficient electrode materials for energy storage devices.

Rational design of hierarchical porous reduced graphene oxide/9,10-phenanthraquinone/porous carbon nanocomposites for high-performance supercapacitors

The development of advanced electrode material is crucial for promoting the application of new high-performance green energy storage devices and remains a great challenge. Herein, by introducing porous carbon (PC) or carbon nanotubes (CNTs) to further modify the redox-active 9,10-phenanthrenequinone (PQ) molecule non-covalently functionalized reduced graphene oxide (RGO), we have designed and synthesized RGO/PQ/PCs (RPPs) and RGO/PQ/CNTs-10 (RPC-10) nanocomposites using a simple one-step solvothermal method. Benefiting from the optimization of the hierarchical porous nanostructures and each composition further strengthens their respective advantages in the novel synthesized nanocomposites (RPPs and RPC-10), the RPPs and RPC-10 electrodes demonstrated significantly superior electrochemical energy storage performance over the RGO and RGO/PQ (RP) electrodes, especially for the RPP-10 electrode with a high specific capacitance of 343.5 F g−1 at 0.5 A g−1 and good rate capability (69.23 %, 0.5 − 40 A g−1). Furthermore, both the symmetric supercapacitor assembled with the optimal RPP-10 electrode and the hybrid supercapacitor assembled with the RPP-10 negative electrode and the NCSRC-24 positive electrode previously reported show excellent energy densities and ultra-long cycling stabilities. This result demonstrates that the synthesized novel RPP-10 nanocomposite is a highly promising candidate for new light-weight, sustainable, high-flexible and high-performance energy storage devices.

In situ fabrication of transition metal phosphide tree-like nanostructure for energy-saving hydrogen production coupled via urea oxidation reaction

Substituting the Oxygen Evolution Reaction (OER) with the Urea Oxidation Reaction (UOR) which is a thermodynamically more favorable option, has paved the way for the production of energy-saving hydrogen as well as the purification of urea-reach waste water. In this study, a nanostructured, porous and active Ni-Cu-Mn-P electrode was created using the dynamic hydrogen bubble template (DHBT) process in different conditions. The fabricated electrodes were utilized as bi-functional electrodes for both the HER and UOR processes. The electrochemical results displayed that the Ni-Cu-Mn-P (which synthesized at current density of 2 A.cm−2) requires only 84 mV overpotential to achieve a current density of 10 mA.cm−2, in HER process, and the necessary potential value for the UOR is only 1.30 V vs RHE. Also, the favorable electrocatalytic stability for industrial applications was also confirmed. The Ni-Cu-Mn-P electrode also demonstrated satisfactory performance in the overall urea electrolysis process and the cell voltage was 1.40 V to generate 10 mA.cm−2. The excellent performance of the electrode was due to the hierarchical porous nanostructure with high active surface area and also the synergistic effect between the elements. This study introduces an effective catalyst design for energy-saving hydrogen production.

Self-sacrificing MOF-derived hierarchical porous In2S3 nanostructures with enhanced photocatalytic performance

Self-sacrificing MOF-derived hierarchical porous In2S3 nanostructures with enhanced photocatalytic performance

Redox-active 9,10-phenanthrenequinone non-covalently modify reduced graphene oxide for high-performance asymmetric supercapacitor and zinc-ion hybrid capacitors

Redox-active organic molecules show great potential in novel renewable energy storage devices by modifying carbon-based materials in covalent or non-covalent forms due to their light-weight, rich structural diversity, good designability and abundance. Herein, we synthesized redox-active 9,10-phenanthrenequinone (PQ) molecules non-covalently modified reduced graphene oxide (RGO) nanocomposites by an improved simple one-step solvothermal method and explored their application as advanced electrode in aqueous energy storage devices. Benefiting from the rich redox-active sites brought by the anchored PQ molecules and the formation of the hierarchical porous network nanostructures with the RGO substrates that facilitates the charge transport and ion diffusion kinetics, the synthesized RGO/PQs nanocomposites exhibit significantly enhanced electrochemical energy storage performance. The optimal RGO/PQ-1.5 electrode has a high specific capacitance of 383.3 F g−1 at 0.5 A g−1 and good rate capability. And the asymmetric supercapacitor (ASC) assembled with the N-RGO negative electrode exhibits significantly better energy density than pure carbon electrode ASCs. More surprisingly, the assembled RGO/PQ-1.5//Zn zinc-ion hybrid capacitor exhibits an attractive specific capacity of 139.4 mAh g−1, a high energy density of 134.6 Wh kg−1, and an ultra-long cycling stability with 95.3 % capacity retention after 14,000 cycles, demonstrating excellent zinc-ion energy storage performance.

Hierarchical porous alumina ceramics as multi-functional support with excellent performance

Hierarchical porous nanostructure alumina ceramics (HP-Al2O3) were prepared through a novel approach involving polymer-assisted freeze-drying and subsequent calcination. The resulting material exhibits interconnected micro-meso-macro pores, distinguishing it from traditional Al2O3 nanoparticles (Al2O3-Nps) prepared without freeze-drying. By manipulating freeze-drying precursors and calcination temperatures, we tailor the morphology and structure of HP-Al2O3. Notably, the HP-Al2O3 demonstrates a remarkable 5.3-fold increase in adsorption efficiency for Congo red compared to Al2O3-Nps, attributed to its significantly larger specific surface area. The HP-Al2O3 is a versatile platform for building multi-functional composites, proved by immobilizing silver nanoparticles (AgNps) and graphitized carbonitride (g-C3N4) through chemical reduction and gas-solid reaction methods, respectively. When employed for the reduction of 4-nitrophenol and the degradation of Rhodamine B, Ag/HP-Al2O3 and g-C3N4/HP-Al2O3 display approximately 2.5 and 2.4 times higher reaction rate constants compared to Ag/Al2O3-Nps and g-C3N4/Al2O3-Nps. This enhanced catalytic performance is attributed to several key factors: the 3D porous framework of the HP-Al2O3 facilitates efficient catalyst immobilization, the microporous and mesoporous nature increases the active site and specific surface area, and the hierarchical porous structure enhances mass diffusion and light capture. Moreover, the self-supporting nature of the HP-Al2O3 simplifies separation and recovery from reaction solutions. With the integration of its hierarchical porous structure and commendable recovery properties, HP-Al2O3 emerges as a promising candidate for various functional applications, particularly in catalysis.

Facile Synthesis of Ordered Mesoporous Orthorhombic Niobium Oxide (T-Nb2O5) for High-Rate Li-Ion Storage with Long Cycling Stability

Herein, we describe the synthesis and evaluation of hierarchical mesoporous orthorhombic niobium oxide (T-Nb2O5) as an anode material for rechargeable lithium-ion batteries (LIB). The as-synthesized material addresses key challenges such as beneficial porous structure, poor rate capability, and cycling performance of the anode for Li-ion devices. The physicochemical characterization results reveal hierarchical porous nanostructure morphology with agglomerated particles and a 20 to 25 nm dimension range. Moreover, the sample has a high specific surface area (~65 m2 g−1) and pore volume (0.135 cm3 g−1). As for the application in Li-ion devices, the T-Nb2O5 delivered an initial discharging capacity as high as 225 mAh g−1 at 0.1 A g−1 and higher rate capability as well as remarkable cycling features (~70% capacity retention after 300 cycles at 250 mA g−1) with 98% average Coulombic efficiency (CE). Furthermore, the scan rate-dependent charge storage mechanism of the T-Nb2O5 electrode material was described, and the findings demonstrate that the electrode shows an evident and highly effective pseudocapacitive Li intercalation behaviour, which is crucial for understanding the electrode process kinetics. The origin of the improved performance of T-Nb2O5 results from the high surface area and mesoporous structure of the nanoparticles.

Electrochemical performance of Zn2VO4/ZnO nanocomposite material derived from Zn-V layered double hydroxides as a cathode for aqueous zinc ion battery

Aqueous zinc ion batteries (AZIBs) with Zn metal as an anode have become one of the ideal choices for grid-scale energy storage presenting the advantages of high safety, low cost, and high theoretical capacity. However, their practical applications are limited by slow electrode reaction kinetics and poor cycling performance. Herein, we successfully prepare Zn2VO4/ZnO nanocomposite materials with graded porous nanosheet morphology by calcining Zn-V layered double hydroxides (Zn-V-LDH) in Ar/H2 mixed gas. Further, the Zn2VO4/ZnO cathode for AZIBs exhibits 232.4 mA h g-1 capacity after 50 cycles at 0.1 A g-1 with 103.8% capacity retention, and could still reach 104.2 mA h g-1 capacity after 8000 cycles at 10 A g-1 with about 100% coulomb efficiency, which excellent electrochemical performance is attributed to the charge redistribution caused by the two-phase interface and the hierarchical porous nano-structures provide abundant reversible Zn2+ storage sites. A series of ex-situ characterizations reveal that Zn2VO4/ZnO electrode undergoes a phase transition to amorphous Zn2VO4/ZnO, which then follows by a classic zinc ion de/intercalation mechanism. In general, the construction of porous nanomaterials with a two-phase synergistic structure could be a major direction for the exploration of cathode materials, which will contribute to the development of high-performance AZIBs.

Fabrication of sodium and MoS2 incorporated NiO and carbon nanostructures for advanced supercapacitor application

Transition metal oxides and carbonaceous nanocomposites have triggered enormous interest in the application of high-performance supercapacitors due to the outstanding electrical conductivity and superior theoretical capacitance. In this study, we prepared highly porous nanostructured NiO/C yolk-shell nanocomposites via a simple calcination of nickel-based metal-organic frameworks. The porosity and electrochemical property were further enhanced by incorporating sodium and hierarchical MoS2 nanostructures via a facile hydrothermal method. It was found that the as-synthesized Na-doped MoS2@NiO/C nanocomposites with hierarchical porosity exhibited superior electrochemical performance. Particularly, the delivered electrochemical capacitance of NiO/C yolk-shell structure was 1779.50 F g−1 in an aqueous electrolyte (2 M KOH), and a superior specific capacitance of 2540.63 F g−1 was acquired after the incorporation of sodium and 2D layered MoS2 into the nanocomposite. When a symmetrical supercapacitor was fabricated, a remarkable energy density of 36.93 Wh kg−1 was recorded in an environmental-friendly aqueous-based electrolyte. More significantly, the outstanding delivered capacitance retention and coulombic efficiency were 111.92 % and 97.6 %, respectively after 4000 continuous GCD cycles. Hence, the Na-doped MoS2@NiO/C with hierarchical porous nanostructures and extraordinary electrochemical performance was explicitly demonstrated in this study and can be utilized as electrode active materials in realizing high-performance supercapacitors.

Fabrication of Hierarchical Porous Metal Oxides by the HPMC-Assisted Gel Combustion Strategy: Incorporation of Nanoceria into Cookie-like Mn2O3 with Enhanced Oxidation Activity and Excellent Water Resistance

Constructing nonprecious metal oxide catalysts with a hierarchical porous structure by a simple method for the deep catalytic oxidation of toxic volatile organic compounds at low temperatures is of great value and significance. In this work, a porous manganese trioxide catalyst (Mn2O3-H) was prepared by a hydroxypropyl methylcellulose-assisted combustion synthesis strategy for catalytic complete oxidation of gaseous toluene. Benefiting from the rich porous nanostructure, Mn2O3-H has much higher specific surface area and active site density, resulting in better low-temperature reducibility and oxygen activation ability than blank Mn2O3 formed by direct calcination. With this sol–gel combustion process, CeO2 nanoparticles could be successfully introduced to form cookie-like Ce–Mn composite oxide with a hierarchical porous nanostructure, which builds the strong interaction of CeO2–Mn2O3 to weaken Mn–O with more active defects. Among Ce-doped catalysts, 5%CeMn-H shows the best catalytic activity in toluene oxidation with 90% conversion temperature at 242 °C under a weight hour space velocity of 60,000 mL·g–1·h–1, which is about 30 and 133 °C lower than that of Mn2O3-H and Mn2O3-B, respectively. This advantage is also shown in other typical hydrocarbons such as propylene and propane. Moreover, the as-prepared Ce-doped catalyst exhibits excellent stability and water resistance ability. This simple robust sol–gel combustion method will provide valuable enlightenment for designing porous catalysts with high performance for related catalytic reactions.

Construction of hierarchical porous 3D nanostructures with high specificity as SERS aptasensors for rapid and ultrasensitive detection of MC-LR

The construction of plasmonic nanostructures is a frontier research area in the field of Surface enhanced Raman scattering (SERS). Three-dimensional (3D) porous materials coupled with aptamers have attracted increasing attention for application in SERS sensing, owing to their great promise towards offering both high specific and ultrasensitive detection capacity. However, most of these SERS sensors are plane-shaped or solution-based, which makes target molecules with a reduced mass transfer, thus leading to a relatively poor capture efficiency. Herein, we demonstrate a capillary-based porous nanostructure coupled with aptamers that can serve as a type of SERS aptasensor for rapid trace detection. The aptasensor was prepared by immobilization of aptamer-modified SERS nanotags on a porous silica monolith which was obtained by an in-situ polymerization in a capillary with a facile fabrication process. The 3D porous silica monolith (3D-PSM) with a hierarchical biporous structure that could enable the rapid permeation of the aqueous phase and provide high specific surface area and active sites, endows the material with high capture efficiency of target molecules. Besides, according to the size of aptamers, stable and uniformed hotspots of 7–8 nm in size were formed, which precisely guaranteed the sensitivity, specificity, and stability of detection. The experimental verification showed that the proposed aptasensor could detect the presence of microcystin-LR at concentrations as low as 0.01 nmol/L, with fast recognition time (10 min), low sample consumption (20 μL), and simple operation. All the results suggest that this new strategy has promising potential in rapid microvolume trace analysis in various fields.

Electrocatalytic oxidation of 5-hydroxymethylfurfural to 2,5-furandicarboxylic acid via metal-organic framework-structured hierarchical Co3O4 nanoplate arrays

Electrocatalytic oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA) was examined as an alternative to thermocatalytic methods in which two-dimensional (2D) cobalt-metal–organic framework (Co-MOF, ZIF-L-Co) nanoplate arrays were prepared on nickel foam (NF) and then transformed into hierarchical porous Co3O4 nanostructures by chemical etching and low temperature annealing to form electrode materials. Hierarchical porous nanoarrays formed during synthesis enlarged the surface area of the as-prepared catalysts introduced a large number of defects and exposed active sites leading to reduced charge diffusion, improved mass transfer and efficient HMF oxidation. Co3O4/NF electrode materials were able to achieve a current density of 10 mA·cm−2 at an overpotential of 105 mV in 1 M KOH with 10 mM HMF, which was reduced by 175 mV compared with water oxidation. Electrocatalytic oxidation experiments afforded 100 % HMF conversion and 96.7 % FDCA yields with a minimum 96.5 % faradaic efficiency at 1.43 V vs RHE. The proposed MOF-structured synthesis method fundamentally reduces charge diffusion, improves mass transfer of electrodes and is generally applicable to fabrication of hierarchical porous nanostructured materials.

A highly efficient electrocatalyst for oxygen reduction reaction: Spinel MnCo2O4 nanoparticles supported on three-dimensional Nitrogen-doped graphene material with interconnected hierarchical porous nanostructure

• MnCo 2 O 4 /3DNG catalyst was prepared by hydrothermal method using 3DNG as support. • 3DNG with hierarchical porous structure possessed enrich the defects and expose more active sites. • MnCo 2 O 4 /3DNG with hierarchical porous structure contributed to improve mass transfer. • MnCo 2 O 4 /3DNG demonstrated excellent ORR activity and higher durability than 20% Pt/C. We designed and synthesized spinel MnCo 2 O 4 nanoparticles supported on three-dimensional nitrogen-doped graphene (NG) with interconnected hierarchical porous nanostructure, in which polymer (2, 5-benzimidazole) (ABPBI) was used as the nitrogen precursor and the carbon precursor. Unique properties of ABPBI including nitrogen-rich aromaticity and rigid plane molecule were conductive to form NG structures through the pyrolysis dehydrogenative and carbonization. The as-prepared MnCo 2 O 4 -3DNG with interconnected hierarchical porous graphene structure possessed enriched defects and more exposed active sites, accelerating mass transport and facilitating diffusion kinetics for better catalytic ORR performance. MnCo 2 O 4 -3DNG exhibited a higher half-wave potential (0.85 V vs RHE) than 20 wt% Pt/C (0.83 V vs RHE). Moreover, the accelerated durability test and i-t chronoamperometry of MnCo 2 O 4 -3DNG revealed more excellent durability than 20 wt% Pt/C. The electrochemical tests results demonstrated that MnCo 2 O 4 -3DNG was promising as a cost-effective non-noble metal catalyst for ORR in fuel cell technology.

Renewable palm oil sticks biomass‐derived unique hierarchical porous carbon nanostructure as sustainability electrode for symmetrical supercapacitor

AbstractBACKGROUNDThree‐dimensional and hierarchical porous materials enriched with 2D nanostructure can boost the electrochemical performance of carbon‐based electrodes in the supercapacitor devices. These materials are obtained from novel precursors of palm oil stock biomass. The unique combination of hierarchical and 2D nanostructures was controlled using ZnCl2 impregnation of 0.3–0.9 mol L−1 with high‐temperature pyrolysis.RESULTSImpregnation with 0.5 mol L−1 ZnCl2 (POSC5) produced the highest specific surface area with dominant micropores of 89% in a total volume of 0.343 cm3 g−1. POSC5 was shown to have an excellent morphological combination of trimodal‐foam‐sponge‐like hierarchical porosity with large messy short 2D nano‐rod structures as the optimum carbon preparation. A symmetrical system was designed as a solid electrode without a binder, confirming high capacitive properties of 256 F g−1 in 1 mol L−1 H2SO4 electrolyte with capacitance retention of 76% at 10 mV s−1. The results showed that the transport and resistance behavior of the charge tends to be stable and satisfactory at an internal resistance of 0.012 Ω, with the energy density increased from 9.14 to 21.19 W h kg−1 at 1 A g−1 in 1 mV s−1.CONCLUSIONTherefore, this research provides an environmentally benign and novel approach for developing a high‐quality, sustainable biomass carbon‐based electrode material for electrochemical energy storage applications. © 2022 Society of Chemical Industry (SCI).

Synthesis of Porous Hierarchical In2O3 Nanostructures with High Methane Sensing Property at Low Working Temperature.

Different hierarchical porous In2O3 nanostructures were synthesized by regulating the hydrothermal time and combining it with a self-pore-forming method. The gas-sensing test results show that the response of the sensor based on In2O3 obtained after hydrothermal reaction for 48 h is about 10.4 to 500 ppm methane. Meanwhile, it possesses good reproducibility, stability, selectivity and moisture resistance as well as a good exponential linear relationship between the response to methane and its concentration. In particular, the sensor based on In2O3 can detect a wide range of methane (10~2000 ppm) at near-room temperature (30 °C). The excellent methane sensitivity of the In2O3 sensor is mainly due to its unique nanostructure, which has the advantages of both porous and hierarchical structures. Combined with the DFT calculation, it is considered that the sensitive mechanism is mainly controlled by the surface adsorbed oxygen model. This work provides a feasible strategy for enhancing the gas sensitivity of In2O3 toward methane at low temperatures.

A self-supported bifunctional air cathode composed of Co3O4/Fe2O3 nanoparticles embedded in nanosheet arrays grafted onto carbon nanofibers for secondary zinc-air batteries

Secondary zinc-air batteries (ZABs) with a free-standing and flexible air electrode integrated with distinguished bifunctional oxygen electrocatalysts are crucial for achieving better performance. Herein, benefitting from the rational design and simple synthesis, a highly controlled design can be achieved for the first showing of the synthesis of Co3O4/Fe2O3NAs@CNFs with a unique hierarchical nanostructure, consisting of randomly distributed zero-dimensional (0D) Co3O4/Fe2O3 nanoparticles embedded in two-dimensional (2D) MOF derived nitrogen-doped mesoporous carbon flake nanoarrays grown on three-dimensional (3D) microporous network with interconnected conductive one-dimensional (1D) carbon nanofibers from carbonized electrospinning polymer nanofiber film (PMNFs). Under the synergy of 3D hierarchical porous nanostructure and abundant accessible active sites, Co3O4/Fe2O3NAs@CNFs is endowed with excellent bifunctional electrocatalytic activities like those of commercial Pt/C and RuO2, respectively. Rechargeable aqueous ZABs based on Co3O4/Fe2O3NAs@CNFs as air electrodes outperform their counterparts based on Pt/C and RuO2 loaded carbon nanofibers (CNFs) as air electrodes, with a maximum power density of 246 mW cm−2 and excellent cycling stability with no increased polarization even after 40 h. And the assembled flexible solid-state ZABs with Co3O4/Fe2O3NAs@CNFs also display superior performance and bendability.

Quasi-Solid-State Electrolyte Membranes Based on Helical Mesoporous Polysilsesquioxane Nanofibers for High-Performance Lithium Batteries

BackgroundTo solve the safety problem aroused by Li dendrites and liquid electrolytes for lithium batteries, this work reported a new solid-state electrolyte technology. MethodHelical mesoporous 1,4-phenylene bridged and 1,2-ethylidene bridged polysilsesquioxane nanofibers were firstly prepared via a sol-gel transcription method, using self-assembled chiral gelator as the template and organic bridged-siloxane as the precursor. After immersing them in ion liquid electrolyte till absorption saturation, two self-standing ionogel electrolyte membranes (EB-IE and EE-IE) were obtained. Significant findingsElectrochemical test showed that they exhibited good thermal stability (up to 327°C and 293 °C, respectively), wide electrochemical window (4.8 V and 5.6 V, respectively) and ideal room temperature ionic conductivity (up to 0.55 and 2.10 mS cm−1, respectively), which was related to their special organic-inorganic hybrid composition and hierarchical porous nanostructure. When they were applied as electrolyte as well as separator in a LiFePO4/Li cell, they performed excellent cycle stability and superior rate performance, which proved the practicability and feasibility of design and application of nanostructured hybrid polymer as quasi-solid state electrolyte scaffold for safe lithium batteries.

High magnetic field-engineered high mass loading sulfides with well-ordered hierarchical nanostructures for all-solid-state supercapacitors

Low energy density is becoming the largest sore point of supercapacitors. Constructing all-solid-state asymmetric supercapacitors (AASCs) with high mass loading and high utilization of electrochemically active materials can largely remedy the drawback. Herein, well-ordered hierarchical porous NiCo2S4 pine needles on carbon cloth (CC) with a loading mass as high as 10.76 mg cm−2 (NCS-12 T) were fabricated by low-temperature topotactic vulcanization of the high-mass-loading (Ni, Co)(CO3)0.5(OH)·0·.11H2O precursor (NCCH-12 T) yielded under 12 T high magnetic field (HMF). The loading mass on each CC tends towards equivalence and increases remarkably with the rise of HMF by guaranteeing sufficient ion supply. Impressively, a high overall capacitance of 10.46F cm−2 at 5 mA cm−2 was achieved without sacrificing the specific capacitance and rate capability that are slightly superior to those of the low mass loading NiCo2S4 electrodes instead. The striking electrochemical performances are ascribed to the available ion and electron transport in the whole electrode, which results from the construction of three-dimensional hierarchical porous nanostructures and HMF-derived well-ordered and uniform deposition via boosting ion transport. Finally, the NCS-12 T-based AASCs with high mass loading exhibit a high energy density of 280 μWh cm−2 at the power density of 1.71 mW cm−2, exceeding most state-of-the-art supercapacitors.