Ordered Mesoporous Carbons

Ordered mesoporous carbons have recently been synthesized using ordered mesoporous silica templates. The synthesis procedure involves infiltration of the pores of the template with appropriate carbon precursor, its carbonization, and subsequent template removal. The template needs to exhibit three‐dimensional pore structure in order to be suitable for the ordered mesoporous carbon synthesis, otherwise disordered microporous carbon is formed. MCM‐48, SBA‐1, and SBA‐15 silicas were successfully used to synthesize carbons with cubic or hexagonal frameworks, narrow mesopore size distributions, high nitrogen Brunauer–Emmett–Teller (BET) specific surface areas (up to 1800 m² g^–1), and large pore volumes. Ordered mesoporous carbons are promising in many applications, including adsorption of large molecules, chromatography, and manufacturing of electrochemical double‐layer capacitors.     

Conformal Coating of Co/N‐Doped Carbon Layers into Mesoporous Silica for Highly Efficient Catalytic Dehydrogenation–Hydrogenation Tandem Reactions

To maximize the utilizing efficiency of cobalt (Co) and optimize its catalytic activity and stability, engineering of size and interfacial chemical properties, as well as controllable support are of ultimate importance. Here, the concept of coating uniform thin Co/N‐doped carbon layers into the mesopore surfaces of mesoporous silica is proposed for heterogeneous aqueous catalysis. To approach the target, a one‐step solvent‐free melting‐assisted coating process, i.e., heating a mixture of a cobalt salt, an amino acid (AA), and a mesoporous silica, is developed for the synthesis of mesoporous composites with thin Co/N‐doped carbon layers uniformly coated within mesoporous silica, high surface areas (250–630 m² g⁻¹), ordered mesopores (7.0–8.4 nm), and high water dispersibility. The strong silica/AA adhesive interactions and AA cohesive interactions direct the uniform coating process. The metal/N coordinating, carbon anchoring, and mesopore confining lead to the formation of tiny Co nanoclusters. The carbon intercalation and N coordination optimize the interfacial properties of Co for catalysis. The optimized catalyst exhibits excellent catalytic performance for tandem hydrogenation of nitrobenzene and dehydrogenation of NaBH₄ with well‐matched reaction kinetics, 100% conversion and selectivity, high turnover frequencies, up to ≈6.06 mol_nitrobenzene mol_Co⁻¹ min⁻¹, the highest over transition‐metal catalysts, and excellent stability and magnetic separability.     

High rate capability of ordered mesoporous carbon with platelet graphitic pore walls for lithium ion anodes

An ordered mesoporous carbon (OMC) with controllable molecule crystal and platelet graphitic pore walls, which is directionally grown on the internal pore walls of SBA-15 or anchors at liquid/silica interfaces by molecule engineering, has been investigated as lithium ion anodes. It is found that the OMC exhibits high kinetics, rate and cycling performance. The i₀ and D_Li are almost constant after 50 cycles. OMC shows a high reversible specific capacity of 153.9 mAh g^-1 at the current density as high as 3500 mA g^-1. The excellent electrochemical performance could be attributed to the presence of the porosity and platelet graphitic pore walls.     

One‐Step Synthesis of Monodispersed Mesoporous Carbon Nanospheres for High‐Performance Flexible Quasi‐Solid‐State Micro‐Supercapacitors

Cost‐effective synthesis of carbon nanospheres with a desirable mesoporous network for diversified energy storage applications remains a challenge. Herein, a direct templating strategy is developed to fabricate monodispersed N‐doped mesoporous carbon nanospheres (NMCSs) with an average particle size of 100 nm, a pore diameter of 4 nm, and a specific area of 1093 m² g^?1. Hexadecyl trimethyl ammonium bromide and tetraethyl orthosilicate not only play key roles in the evolution of mesopores but also guide the assembly of phenolic resins to generate carbon nanospheres. Benefiting from the high surface area and optimum mesopore structure, NMCSs deliver a large specific capacitance up to 433 F g^?1 in 1 m H₂SO₄. The NMCS electrodes–based symmetric sandwich supercapacitor has an output voltage of 1.4 V in polyvinyl alcohol/H₂SO₄ gel electrolyte and delivers an energy density of 10.9 Wh kg^?1 at a power density of 14014.5 W kg^?1. Notably, NMCSs can be directly applied through the mask‐assisted casting technique by a doctor blade to fabricate micro‐supercapacitors. The micro‐supercapacitors exhibit excellent mechanical flexibility, long‐term stability, and reliable power output.     

Core‐Cone Structured Monodispersed Mesoporous Silica Nanoparticles with Ultra‐large Cavity for Protein Delivery

A new type of monodispersed mesoporous silica nanoparticles with a core–cone structure (MSN‐CC) has been synthesized. The large cone‐shaped pores are formed by silica lamellae closely packed encircling a spherical core, showing a structure similar to the flower dahlia. MSN‐CC has a large pore size of 45 nm and a high pore volume of 2.59 cm³ g⁻¹. MSN‐CC demonstrates a high loading capacity of large proteins and successfully delivers active β‐galactosidase into cells, showing their potential as efficient nanocarriers for the cellular delivery of proteins with large molecular weights.     

Solvent‐Free Self‐Assembly to the Synthesis of Nitrogen‐Doped Ordered Mesoporous Polymers for Highly Selective Capture and Conversion of CO2

A solvent‐free induced self‐assembly technology for the synthesis of nitrogen‐doped ordered mesoporous polymers (N‐OMPs) is developed, which is realized by mixing polymer precursors with block copolymer templates, curing at 140–180 °C, and calcination to remove the templates. This synthetic strategy represents a significant advancement in the preparation of functional porous polymers through a fast and scalable yet environmentally friendly route, since no solvents or catalysts are used. The synthesized N‐OMPs and their derived catalysts are found to exhibit competitive CO₂ capacities (0.67–0.91 mmol g^?1 at 25 °C and 0.15 bar), extraordinary CO₂/N₂ selectivities (98–205 at 25 °C), and excellent activities for catalyzing conversion of CO₂ into cyclic carbonate (conversion >95% at 100 °C and 1.2 MPa for 1.5 h). The solvent‐free technology developed in this work can also be extended to the synthesis of N‐OMP/SiO₂ nanocomposites, mesoporous SiO₂, crystalline mesoporous TiO₂, and TiPO, demonstrating its wide applicability in porous material synthesis.     

Multilayer Amorphous‐Si‐B‐C‐N/γ‐Al2O3/α‐Al2O3 Membranes for Hydrogen Purification

The hydrogen and carbon monoxide separation is an important step in the hydrogen production process. If H₂ can be selectively removed from the product side during hydrogen production in membrane reactors, then it would be possible to achieve complete CO conversion in a single‐step under high temperature conditions. In the present work, the multilayer amorphous‐Si‐B‐C‐N/γ‐Al₂O₃/α‐Al₂O₃ membranes with gradient porosity have been realized and assessed with respect to the thermal stability, geometry of pore space and H₂/CO permeance. The α‐Al₂O₃ support has a bimodal pore‐size distribution of about 0.64 and 0.045 µm being macroporous and the intermediate γ‐Al₂O₃ layer—deposited from boehmite colloidal dispersion—has an average pore‐size of 8 nm being mesoporous. The results obtained by the N₂‐adsorption method indicate a decrease in the volume of micropores—0.35 vs. 0.75 cm³ g^?1—and a smaller pore size ?6.8 vs. 7.4 Å—in membranes with the intermediate mesoporous γ‐Al₂O₃ layer if compared to those without. The three times Si‐B‐C‐N coated multilayer membranes show higher H₂/CO permselectivities of about 10.5 and the H₂ permeance of about 1.05 × 10^?8 mol m^?2 s^?1 Pa^?1. If compared to the state of the art of microporous membranes, the multilayer Si‐B‐C‐N/γ‐Al₂O₃/α‐Al₂O₃ membranes are appeared to be interesting candidates for hydrogen separation because of their tunable nature and high‐temperature and high‐pressure stability.     

3D Mesoporous Graphene: CVD Self‐Assembly on Porous Oxide Templates and Applications in High‐Stable Li‐S Batteries

A nanostructured carbon with high specific surface area (SSA), tunable pore structure, superior electrical conductivity, mechanically robust framework, and high chemical stability is an important requirement for electrochemical energy storage. Porous graphene fabricated by chemical activation and liquid etching has a high surface area but very limited volume of electrochemically accessible mesopores. Herein, an effective strategy of in situ formation of hierarchically mesoporous oxide templates with small pores induced by Kirkendall diffusion and large pores attributed to evaporation of deliberately introduced volatile metal is proposed for chemical vapor deposition assembly of porous graphene frameworks (PGFs). The PGFs inherit the hierarchical mesoporous structure of the templates. A high SSA of 1448 m² g⁻¹, 91.6% of which is contributed by mesopores, and a mesopore volume of 2.40 cm³ g⁻¹ are attained for PGFs serving as reservoirs of ions or active materials in electrochemical energy storage applications. When the PGFs are applied in lithium‐sulfur batteries, a very high sulfur utilization of 71% and a very low fading rate of ≈0.04% per cycle after the second cycle are achieved at a current rate of 1.0 C. This work provides a general strategy for the rational construction of mesoporous structures induced by a volatile metal, with a view toward the design of hierarchical nanomaterials for advanced energy storage.     

Micro‐Blooming: Hierarchically Porous Nitrogen‐Doped Carbon Flowers Derived from Metal‐Organic Mesocrystals

Synthesis of 3D flower‐like zinc‐nitrilotriacetic acid (ZnNTA) mesocrystals and their conformal transformation to hierarchically porous N‐doped carbon superstructures is reported. During the solvothermal reaction, 2D nanosheet primary building blocks undergo oriented attachment and mesoscale assembly forming stacked layers. The secondary nucleation and growth preferentially occurs at the edges and defects of the layers, leading to formation of 3D flower‐like mesocrystals comprised of interconnected 2D micropetals. By simply varying the pyrolysis temperature (550–1000 °C) and the removal method of in the situ‐generated Zn species, nonporous parent mesocrystals are transformed to hierarchically porous carbon flowers with controllable surface area (970–1605 m² g^?1), nitrogen content (3.4–14.1 at%), pore volume (0.95–2.19 cm³ g^?1), as well as pore diameter and structures. The carbon flowers prepared at 550 °C show high CO₂/N₂ selectivity due to the high nitrogen content and the large fraction of (ultra)micropores, which can greatly increase the CO₂ affinity. The results show that the physicochemical properties of carbons are highly dependent on the thermal transformation and associated pore formation process, rather than directly inherited from parent precursors. The present strategy demonstrates metal‐organic mesocrystals as a facile and versatile means toward 3D hierarchical carbon superstructures that are attractive for a number of potential applications.     

Recent Progress in the Synthesis of Porous Carbon Materials

In this review, the progress made in the last ten years concerning the synthesis of porous carbon materials is summarized. Porous carbon materials with various pore sizes and pore structures have been synthesized using several different routes. Microporous activated carbons have been synthesized through the activation process. Ordered microporous carbon materials have been synthesized using zeolites as templates. Mesoporous carbons with a disordered pore structure have been synthesized using various methods, including catalytic activation using metal species, carbonization of polymer/polymer blends, carbonization of organic aerogels, and template synthesis using silica nanoparticles. Ordered mesoporous carbons with various pore structures have been synthesized using mesoporous silica materials such as MCM‐48, HMS, SBA‐15, MCF, and MSU‐X as templates. Ordered mesoporous carbons with graphitic pore walls have been synthesized using soft‐carbon sources that can be converted to highly ordered graphite at high temperature. Hierarchically ordered mesoporous carbon materials have been synthesized using various designed silica templates. Some of these mesoporous carbon materials have successfully been used as adsorbents for bulky pollutants, as electrodes for supercapacitors and fuel cells, and as hosts for enzyme immobilization. Ordered macroporous carbon materials have been synthesized using colloidal crystals as templates. One‐dimensional carbon nanostructured materials have been fabricated using anodic aluminum oxide (AAO) as a template.     

Mesoporous‐Silica‐Coated Up‐Conversion Fluorescent Nanoparticles for Photodynamic Therapy

Near‐infrared (NIR)‐to‐visible up‐conversion fluorescent nanoparticles have potential to be used for photodynamic therapy (PDT) in deep tissue because NIR light can penetrate thick tissue due to weak absorption in the optical window. Here a uniform layer of mesoporous silica is coated onto NaYF₄ up‐converting nanocrystals, with a large surface area of ≈770 m² g^?1 and an average pore size of 2 nm. A photosensitizer, zinc phthalocyanine, is incorporated into the mesoporous silica. Upon excitation by a NIR laser, the nanocrystals convert NIR light to visible light, which further activates the photosensitizer to release reactive singlet oxygen to kill cancer cells. The photosensitizer encapsulated in mesoporous silica is protected from degradation in the harsh biological environment. It is demonstrated that the photosensitizers loaded into the porous silica shell of the nanoparticles are not released out of the silica while they continuously produce singlet oxygen upon excitation by a NIR laser. The nanoparticles are reusable as the photosensitizers encapsulated in the silica are removed by soaking in ethanol.     

Formation of N‐Doped Carbon‐Coated ZnO/ZnCo2O4/CuCo2O4 Derived from a Polymetallic Metal–Organic Framework: Toward High‐Rate and Long‐Cycle‐Life Lithium Storage

Metal–organic frameworks (MOFs) are very promising self‐sacrificing templates for the large‐scale fabrication of new functional materials owing to their versatile functionalities and tunable porosities. Most conventional metal oxide electrodes derived from MOFs are limited by the low abundance of incorporated metal elements. This study reports a new strategy for the synthesis of multicomponent active metal oxides by the pyrolysis of polymetallic MOF precursors. A hollow N‐doped carbon‐coated ZnO/ZnCo₂O₄/CuCo₂O₄ nanohybrid is prepared by the thermal annealing of a polymetallic MOF with ammonium bicarbonate as a pore‐forming agent. This is the first report on the rational design and preparation of a hybrid composed of three active metal oxide components originating from MOF precursors. Interestingly, as a lithium‐ion battery anode, the developed electrode delivers a reversible capacity of 1742 mAh g^?1 after 500 cycles at a current density of 0.3 mA g^?1. Furthermore, the material shows large storage capacities (1009 and 667 mAh g^?1), even at high current flow (3 and 10 A g^?1). The remarkable high‐rate capability and outstanding long‐life cycling stability of the multidoped metal oxide benefits from the carbon‐coated integrated nanostructure with a hollow interior and the three active metal oxide components.     

Highly Electrochemically‐Reversible Mesoporous Na2FePO4F/C as Cathode Material for High‐Performance Sodium‐Ion Batteries

As promising cathode materials, iron‐based phosphate compounds have attracted wide attention for sodium‐ion batteries due to their low cost and safety. Among them, sodium iron fluorophosphate (Na₂FePO₄F) is widely noted due to its layered structure and high operating voltage compared with NaFePO₄. Here, a mesoporous Na₂FePO₄F@C (M‐NFPF@C) composite derived from mesoporous FePO₄ is synthesized through a facile ball‐milling combined calcination method. Benefiting from the mesoporous structure and highly conductive carbon, the M‐NFPF@C material exhibits a high reversible capacity of 114 mAh g^?1 at 0.1 C, excellent rate capability (42 mAh g^?1 at 10 C), and good cycling performance (55% retention after 600 cycles at 5 C). The high plateau capacity obtained (>90% of total capacity) not only shows high electrochemical reversibility of the as‐prepared M‐NFPF@C but also provides high energy density, which mainly originates from its mesoporous structure derived from the mesoporous FePO₄ precursor. The M‐NFPF@C serves as a promising cathode material with high performance and low cost for sodium‐ion batteries.     

Mechanochemical Synthesis of γ‐Graphyne with Enhanced Lithium Storage Performance

γ‐Graphyne is a new nanostructured carbon material with large theoretical Li⁺ storage due to its unique large conjugate rings, which makes it a potential anode for high‐capacity lithium‐ion batteries (LIBs). In this work, γ‐graphyne‐based high‐capacity LIBs are demonstrated experimentally. γ‐Graphyne is synthesized through mechanochemical and calcination processes by using CaC₂ and C₆Br₆. Brunauer–Emmett–Teller, atomic force microscopy, X‐ray photoelectron spectroscopy, solid‐state ¹³C NMR and Raman spectra are conducted to confirm its morphology and chemical structure. The sample presents 2D mesoporous structure and is exactly composed of sp and sp²‐hybridized carbon atoms as the γ‐graphyne structure. The electrode shows high Li⁺ storage (1104.5 mAh g^?1 at 100 mA g^?1) and rate capability (435.1 mAh g^?1 at 5 A g^?1). The capacity retention can be up to 948.6 (200 mA g^?1 for 350 cycles) and 730.4 mAh g^?1 (1 A g^?1 for 600 cycles), respectively. These excellent electrochemical performances are ascribed to the mesoporous architecture, large conjugate rings, enlarged interplanar distance, and high structural integrity for fast Li⁺ diffusion and improved cycling stability in γ‐graphyne. This work provides an environmentally benign and cost‐effective mechanochemical method to synthesize γ‐graphyne and demonstrates its superior Li⁺ storage experimentally.     

MOF‐Derived Hollow Co9S8 Nanoparticles Embedded in Graphitic Carbon Nanocages with Superior Li‐Ion Storage

Novel electrode materials consisting of hollow cobalt sulfide nanoparticles embedded in graphitic carbon nanocages (HCSP?GCC) are facilely synthesized by a top‐down route applying room‐temperature synthesized Co‐based zeolitic imidazolate framework (ZIF‐67) as the template. Owing to the good mechanical flexibility and pronounced structure stability of carbon nanocages‐encapsulated Co₉S₈, the as‐obtained HCSP?GCC exhibit superior Li‐ion storage. Working in the voltage of 1.0?3.0 V, they display a very high energy density (707 Wh kg^?1), superior rate capability (reversible capabilities of 536, 489, 438, 393, 345, and 278 mA h g^?1 at 0.2, 0.5, 1, 2, 5, and 10C, respectively), and stable cycling performance (≈26% capacity loss after long 150 cycles at 1C with a capacity retention of 365 mA h g^?1). When the work voltage is extended into 0.01–3.0 V, a higher stable capacity of 1600 mA h g^?1 at a current density of 100 mA g^?1 is still achieved.     

Quantitative Control of Pore Size of Mesoporous Carbon Nanospheres through the Self‐Assembly of Diblock Copolymer Micelles in Solution

This paper reports facile synthesis of nitrogen‐doped mesoporous carbon nanospheres (MCNSs) with average diameters of around 300 nm and well‐controlled pore sizes ranging from 8 to 38 nm, by employing polystyrene‐b‐poly(ethylene oxide) (PS‐b‐PEO) diblocks with different PS block lengths as the soft templates and dopamine as the carbon‐rich precursor. For the first time, a linear equation is achieved for the quantitative control of the average pore size of MCNSs by simply adjusting a block length of diblock copolymer. The resultant MCNSs possess high surface areas of up to 450 m² g^?1 and nitrogen doping contents of up to ≈3 wt%. As electrode materials of supercapacitors, the MCNSs exhibit excellent electrochemical performance with high specific capacitances of up to 350 F g^?1 at 0.1 A g^?1, superior rate capability, and cycling stability. Interestingly, the specific capacitance of the MCNSs reduces linearly with increasing pore size, whereas the normalized capacitance by specific surface area remains invariable. This represents a new spectrum of the relationship between electrochemical capacitance and pore size (>5 nm) for porous carbons, which makes a complement to the existing spectra focusing on pore diameters of <5 nm.     

Bimetal‐Organic‐Framework Derivation of Ball‐Cactus‐Like Ni‐Sn‐P@C‐CNT as Long‐Cycle Anode for Lithium Ion Battery

Metal phosphides are a new class of potential high‐capacity anodes for lithium ion batteries, but their short cycle life is the critical problem to hinder its practical application. A unique ball‐cactus‐like microsphere of carbon coated NiP₂/Ni₃Sn₄ with deep‐rooted carbon nanotubes (Ni‐Sn‐P@C‐CNT) is demonstrated in this work to solve this problem. Bimetal‐organic‐frameworks (BMOFs, Ni‐Sn‐BTC, BTC refers to 1,3,5‐benzenetricarboxylic acid) are formed by a two‐step uniform microwave‐assisted irradiation approach and used as the precursor to grow Ni‐Sn@C‐CNT, Ni‐Sn‐P@C‐CNT, yolk–shell Ni‐Sn@C, and Ni‐Sn‐P@C. The uniform carbon overlayer is formed by the decomposition of organic ligands from MOFs and small CNTs are deeply rooted in Ni‐Sn‐P@C microsphere due to the in situ catalysis effect of Ni‐Sn. Among these potential anode materials, the Ni‐Sn‐P@C‐CNT is found to be a promising anode with best electrochemical properties. It exhibits a large reversible capacity of 704 mA h g^?1 after 200 cycles at 100 mA g^?1 and excellent high‐rate cycling performance (a stable capacity of 504 mA h g^?1 retained after 800 cycles at 1 A g^?1). These good electrochemical properties are mainly ascribed to the unique 3D mesoporous structure design along with dual active components showing synergistic electrochemical activity within different voltage windows.     

Modulating Ion Diffusivity and Electrode Conductivity of Carbon Nanotube@Mesoporous Carbon Fibers for High Performance Aluminum–Selenium Batteries

Selenium (Se)‐based rechargeable aluminum batteries (RABs), known as aluminum–selenium (Al–Se) batteries, are an appealing new battery design that holds great promise for addressing the low‐capacity problem of current RAB technology. However, their applications are hindered by mediocre high‐rate capacity (≈100 mAh g^?1 at 0.5 A g^?1) and insufficient cycling life (50 cycles). Herein, the synthesis of mesoporous carbon fibers (MCFs) by coating mesoporous carbon with short‐length mesopores and tunable mesopore sizes (2.7 to 8.9 nm) coaxially on carbon nanotubes (CNT) is reported. When compositing MCFs with Se for Al–Se batteries, a positive correlation between mesopore size and electrolyte ion diffusivity is observed, however when pore size is increased to 8.9 nm, large voids are created at the interface of CNT core and mesoporous carbon shell, leading to decreased electrode conductivity. The trade‐off between ion diffusivity and interfacial connectivity/conductivity determines MCF with pore size of 7.1 nm as the best host material for Al–Se batteries. The composite cathode delivers high specific capacities (366 and 230 mAh g^?1 at 0.5 and 1 A g^?1), good rate performance, and excellent cycling stability (152 mAh g^?1 after 500 cycles at 2 A g^?1), superior over previously reported Se cathodes and other cathodes for RABs.     

Scalable 2D Mesoporous Silicon Nanosheets for High‐Performance Lithium‐Ion Battery Anode

Constructing unique mesoporous 2D Si nanostructures to shorten the lithium‐ion diffusion pathway, facilitate interfacial charge transfer, and enlarge the electrode–electrolyte interface offers exciting opportunities in future high‐performance lithium‐ion batteries. However, simultaneous realization of 2D and mesoporous structures for Si material is quite difficult due to its non‐van der Waals structure. Here, the coexistence of both mesoporous and 2D ultrathin nanosheets in the Si anodes and considerably high surface area (381.6 m² g^?1) are successfully achieved by a scalable and cost‐efficient method. After being encapsulated with the homogeneous carbon layer, the Si/C nanocomposite anodes achieve outstanding reversible capacity, high cycle stability, and excellent rate capability. In particular, the reversible capacity reaches 1072.2 mA h g^?1 at 4 A g^?1 even after 500 cycles. The obvious enhancements can be attributed to the synergistic effect between the unique 2D mesoporous nanostructure and carbon capsulation. Furthermore, full‐cell evaluations indicate that the unique Si/C nanostructures have a great potential in the next‐generation lithium‐ion battery. These findings not only greatly improve the electrochemical performances of Si anode, but also shine some light on designing the unique nanomaterials for various energy devices.     

Mesoporous and Nanostructured TiO2 layer with Ultra‐High Loading on Nitrogen‐Doped Carbon Foams as Flexible and Free‐Standing Electrodes for Lithium‐Ion Batteries

A simple and green method is developed for the preparation of nanostructured TiO₂ supported on nitrogen‐doped carbon foams (NCFs) as a free‐standing and flexible electrode for lithium‐ion batteries (LIBs), in which the TiO₂ with 2.5–4 times higher loading than the conventional TiO₂‐based flexible electrodes acts as the active material. In addition, the NCFs act as a flexible substrate and efficient conductive networks. The nanocrystalline TiO₂ with a uniform size of ≈10 nm form a mesoporous layer covering the wall of the carbon foam. When used directly as a flexible electrode in a LIB, a capacity of 188 mA h g^?1 is achieved at a current density of 200 mA g^?1 for a potential window of 1.0–3.0 V, and a specific capacity of 149 mA h g^?1 after 100 cycles at a current density of 1000 mA g^?1 is maintained. The highly conductive NCF and flexible network, the mesoporous structure and nanocrystalline size of the TiO₂ phase, the firm adhesion of TiO₂ over the wall of the NCFs, the small volume change in the TiO₂ during the charge/discharge processes, and the high cut‐off potential contribute to the excellent capacity, rate capability, and cycling stability of the TiO₂/NCFs flexible electrode.