Compositing SrLi2Ti6O14 with chemical deposited silver for enhancing lithium ion storage

One of the main issues for titanium-based anode materials is their poor electronic conductivity and this issue can affect their rate performance. For conquering this drawback, many approaches have been proposed. In this report, SrLi₂Ti₆O₁₄ as one of the titanium-based anode materials is prepared via a facile sol–gel method and subsequently it has been composited with silver to elevate its electronic conductivity. Upon the analysis of electrochemical results, the SrLi₂Ti₆O₁₄/Ag composite with 6?wt% Ag can deliver an initial capacity of 164.9?mAh?g^?1. After 50 cycles, the sample can still retain 154.6?mAh?g^?1 with 93.8% retention of the first cycle. Meanwhile, the SrLi₂Ti₆O₁₄/Ag composite with 6?wt% Ag can also exhibit good rate capacities, even at 300?mA?g^?1, its capacity can be firmly kept at 140.0?mAh?g^?1. In addition, in situ X-ray diffraction characterization shows the structural reversibility of the SrLi₂Ti₆O₁₄/Ag composite with 6?wt% Ag during cycling. All the electrochemical results indicate that the SrLi₂Ti₆O₁₄/Ag composite with 6?wt% Ag can be a promising anode material for lithium ion batteries.     

Preparation of LiNi1/3Co1/3Mn1/3O2/polytriphenylamine cathode composites with enhanced electrochemical performances towards reversible lithium storage

A series of LiNi_1/3Co_1/3Mn_1/3O₂/polytriphenylamine composites were successfully synthesized by ultrasound dispersion method. LiNi_1/3Co_1/3Mn_1/3O₂/polytriphenylamine (5.0?wt%) composite with small and homogeneous particle size exhibited excellent electrochemical performance, which delivered an initial discharge capacity of 223.7?mAh g^?1 with a capacity retention of 84.39% after 100 cycles in the voltage range of 2.5–4.5?V and at a current density of 0.2C. Moreover, an excellent specific discharge capacity of 127.3?mAh g^?1 at a current density 5C indicates a superior rate performance of the LiNi_1/3Co_1/3Mn_1/3O₂/polytriphenylamine (5.0?wt%) composite. The good electrochemical performances of the composite can be attributed to the introduction of polytriphenylamine, which increased electrical conductivity, decreased charge transfer resistance and increased Li⁺ ion diffusion ability. These noteworthy results demonstrated that LiNi_1/3Co_1/3Mn_1/3O₂/polytriphenylamine composites might be potential cathode materials for lithium ion batteries.     

Synthesis and electrochemical properties of mixed-phase αx/β1-x-LiVOPO4/C composites

Mixed-phase α_x/β_1-x-LiVOPO₄/C (x = 0.1, 0.3, 0.5, 0.7, 0.9) composites were synthesized by the solid-phase sintering method. X-ray diffraction (XRD) analyses revealed that a series of composites were comprised of pure triclinic α-LiVOPO₄ and orthorhombic β-LiVOPO₄ components. The mixed-phase materials exhibit better rate performance than whether pure triclinic α-LiVOPO₄/C or orthorhombic β-LiVOPO₄/C. The α_0.5/β_0.5-LiVOPO₄/C (α:β = 1:1) composite exhibit superior high-rate capability. When cycled at 2C and 5C, the initial discharge capacities of the α_0.5/β_0.5-LiVOPO₄/C composite are 81.1 mAh g^?1 and 69.8 mAh g^?1 respectively, which are significantly higher than those of the pure α-LiVOPO₄/C (30.6 mAh g^?1 and 18.6 mAh g^?1, respectively) and β-LiVOPO₄/C (56.8 mAh g^?1 and 36.9 mAh g^?1, respectively). The improved electrochemical performance could be attributed to the mixed phase possess an open framework and stable structure.     

Nanoparticles constructed mesoporous coral-like Mn2O3 as high performance anode for lithium-ion batteries

As well established, the morphology and architecture of electrode materials greatly contribute to the electrochemical properties. Herein, a novel structure of mesoporous coral-like manganese (III) oxide (Mn₂O₃) is synthesized via a facile solvothermal method coupled with the carbonization under air. When fabricated as anode electrode for lithium-ion batteries (LIBs), the as-prepared Mn₂O₃ exhibits good electrochemical properties, showing a high discharge capacity of 1090.4 mAh g^?1 at 0.1 A g^?1, and excellent rate performance of 410.4 mAh g^?1 at 2 A g^?1. Furthermore, it maintains the reversible discharge capacity of 1045 mAh g^?1 at 0.1 A g^?1 after 380 cycles, and 755 mAh g^?1 at 1 A g^?1 after 450 cycles. The durable cycling stability and outstanding rate performance can be attributed to its unique 3D mesoporous structure, which is favorable for increasing active area and shortening Li⁺ diffusion distance.     

Synthesis of 1D-MoS2/graphene nanotubes aided with sodium chloride for reversible lithium storage

A novel negative material consisting of graphene nanotubes and ultrathin MoS₂ is synthesized by a simple one-step hydrothermal method assisted with Sodium chloride. The MoS₂/Graphene electrodes deliver a specific capacity of 1350 mAh g^?1 under 0.1 A g^?1 and high rate capability (retaining 85.5% capacity from 0.1 A g^?1 to 0.8 A g^?1). A high remarkable capacity of 820 mAh g^?1 can still be recovered at 0.5 A g^?1 after 500 cycles, and the average coulombic efficiency was as high as 99.98% during the additional 500 cycles. The excellent Li-ion storage performance of MoS₂/Graphene nanotubes may be attributed to the ultra-thin MoS₂ flakes and curled graphene nanotubes. This structural feature has a strong adsorption capacity for lithium ions, which can provide a broad space for ion storage. A large number of active sites dispersed in the layered molybdenum disulfide promote the kinetics of the electrochemical reaction, empowering the ultra-thin layered molybdenum disulfide to get a higher theoretical capacity. In addition, the existence of the tubular structure alleviates volume expansion and provides a way for the rapid movement of electrons and diffusion of Li⁺ during repeated cycles.     

Agar-assisted sol-gel synthesis and electrochemical characterization of TiNb2O7 anode materials for lithium-ion batteries

TiNb₂O₇ powders are synthesized via a newly developed agar-assisted sol-gel process for the first time. Phase-pure TiNb₂O₇ powders are obtained upon calcination at 800 °C. On contrast, TiNb₂O₇ powders synthesized via the conventional solid-state method require high calcination temperature at 1100 °C for the complete compound formation. The samples synthesized with agar improve the morphology with submicron-sized particles. The formed porous structure is favorable for enhancing the electrochemical kinetics due to the large contact area between the electrode and the electrolyte. Based on the electrochemical active surface area analysis, the electrical double-layer capacitance of TiNb₂O₇ powders synthesized via both the agar-assisted and the solid-state method is 145 mF cm^?2 and 22 mF cm^?2, respectively. The electrochemical active surface area of the sample prepared via the agar-assisted method is higher than that of the sample prepared via the solid-state method. The TiNb₂O₇ sample synthesized via the agar-assisted process yields 284 mAh g^?1 at 0.1 C, whereas the sample synthesized via the conventional solid-state method yields only 265 mAh g^?1 at 0.1 C. The discharge capacities of the agar-assisted synthesized sample are 205 mAh g^?1 and 174 mAh g^?1 at 5 C and 10 C, respectively. Moreover, the sample exhibits high capacity retention of 91% after 100 discharge-charge cycles at 5 C. Based on the obtained results, the agar-assisted sol-gel process is inferred as one of the facile methods for preparing high performance anode materials for lithium-ion batteries.     

Fast Li-ion conductor Li1+yTi2-yAly(PO4)3 modified Li1.2[Mn0.54Ni0.13Co0.13]O2 as high performance cathode material for Li-ion battery

In the material of xLi₂MnO₃ ·(1-x) LiMO₂ (0 < x < 1), the Li₂MnO₃ component is used to stabilize the layered LiMO₂ structure. However, the electrochemical inactive Li₂MnO₃ makes Li-ion diffusion difficult, leading to a sluggish rate capability. In this work, Li_1.3Ti_1.7Al_0.3(PO₄)₃ (LTA0.3), a NASICON-type Li-ion conductor, is applied to modified Li_1.2Mn_0.54Ni_0.13Co_0.13O₂ to overcome the above shortcoming. Additionally, the Li-ion conductivity of LiTi₂(PO₄)₃ can be improved effectively by replacing tetravalent cation Ti⁴⁺ with trivalent Al³⁺ at the optimal ratio. At 1C rate, the LR cathode with 3 wt% LTA0.3 delivers 200 mAh g^?1 after 170 cycles and maintains 140 mAh g^?1 after 500 cycles. Moreover, the modified cathode shows an enhanced rate performance of 169.7 mAh g^?1 at 5C. Enhanced cycle durability and rate capability are aroused by the 3D skeletal framework of LTA0.3, which is suitable for Li-ion diffusion. The LTA0.3 coating layer displays a robust shell which not only avoids the corrosion of electrode materials but also effectively facilitates Li-ion diffusion.     

High capacity ZnFe2O4 anode material for lithium ion batteries

A nanostructured ternary transition metal oxide, ZnFe₂O₄, is synthesized via the simple polymer pyrolysis method. The characteristics of the material are examined by thermogravimetry, Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The electrochemical test results show that this method of ZnFe₂O₄ synthesis produces high specific capacities and good cycling performance, with an initial specific capacity as high as 1419.6 mAh g⁻¹ at first discharge that is maintained at over 800 mAh g⁻¹ even after 50 charge–discharge cycles. The electrode also presents a good rate capability, with a high rate of 4C (1C = 928 mA g⁻¹), a reversible specific capacity that can be as high as 400 mAh g⁻¹. ZnFe₂O₄ is a potential alternative to high-performance nanostructured anode material in lithium ion batteries.     

CNT@TiO2 nanohybrids for high-performance anode of lithium-ion batteries

This work describes a potential anode material for lithium-ion batteries (LIBs), namely, anatase TiO₂ nanoparticle-decorated carbon nanotubes (CNTs@TiO₂). The electrochemical properties of CNTs@TiO₂ were thoroughly investigated using various electrochemical techniques, including cyclic voltammetry, electrochemical impedance spectroscopy, galvanostatic cycling, and rate experiments. It was revealed that compared with pure TiO₂ nanoparticles and CNTs alone, the CNT@TiO₂ nanohybrids offered superior rate capability and achieved better cycling performance when used as anodes of LIBs. The CNT@TiO₂ nanohybrids exhibited a cycling stability with high reversible capacity of about 190 mAh g^-1 after 120 cycles at a current density of 100 mA g^-1 and an excellent rate capability (up to 100 mAh g^-1 at a current density of 1,000 mA g^-1).     

Microwave-assisted one-pot synthesis of SnC2O4/graphene composite anode material for lithium-ion batteries

Currently, SnC₂O₄ is considered as one of the most promising anode materials for high-energy lithium-ion batteries (LIBs) because its charge capacity is higher than that of metal oxides. Herein, a facile microwave-assisted solvothermal method was employed to obtain SnC₂O₄/GO composites within only 30?min, which is time-efficient. The amount of SnC₂O₄ was increased to 95.3?wt% to improve the capacity of the composite. Pure SnC₂O₄ with a high specific surface area of 19.6?m² g^?1 without any other tin compound was used for fabrication. The SnC₂O₄/GO composite exhibited excellent electrochemical performance, with reversible discharge/charge capacity of 657/659?mA?h?g^?1 after 100 cycles at 0.2?A?g^?1. Furthermore, at high current densities of 1.0 and 2.0?A?g^?1, the SnC₂O₄/GO composite anode exhibited high reversible discharge/charge capacities of 553/552 and 418/414?mA?h?g^?1, respectively, after 200 cycles at room temperature. These improvements were likely obtained because SnC₂O₄ was well composited with graphene, which not only offered rapid electron transfer but also released the tension produced by the volumetric effect during repeated lithiation/delithiation. Cyclic voltammetry (CV) was also performed to further study the electrochemical reactions of SnC₂O₄/GO. The facile microwave-assisted solvothermal method used herein is considered as a highly efficient method to fabricate metal oxalate/graphene composites for use as anode materials in LIBs.     

NiSe2 encapsulated in N-doped TiN/carbon nanoparticles intertwined with CNTs for enhanced Na-ion storage by pseudocapacitance

Transitional metal selenides are considered as potential anode candidates for sodium-ion batteries (SIBs) because of their relatively high theoretical capacity and environmental benign. However, the large volume change derived from the conversion reaction and the sluggish kinetics due to the inherent low electrochemical conductivity hinder their practical application. Herein, composite materials of NiSe₂ encapsulated in nitrogen-doped TiN/carbon nanoparticles with carbon nanotubes (CNTs) on the surface (NiSe₂@N-TCP/CNTs) are fabricated via pyrolysis and selenization processes. In this composite, TiN inside the carbon matrix can enhance the conductivity and structural stability. CNTs that are in-situ grown on the surface not only further enhance the conductivity of the composites, but also offer sufficient space to buffer the volume expansion and alleviate serious aggregation of NiSe₂ nanoparticles. Benefit from these merits, the NiSe₂@N-TCP/CNTs showed a lower charge transfer resistance and a faster Na⁺ diffusion rate than materials without growing CNTs. When used as the anode of SIBs, the NiSe₂@N-TCP/CNTs electrode delivered a reversible capacity of 344.0 mAh g^?1 after 1000 cycles at 0.2 A g^?1, and still maintained at 272.7 mAh g^?1 even at a high current density of 2 A g^?1. The remarkable electrochemical performance is mainly attributed to the special designed hierarchical structures and pseudocapacitance sodium storage behavior.     

Design and synthesis of NiCo2O4/NiCoO2/graphene hybrid nanoarrays with enhanced capacitive performance

NiCo₂O₄/NiCoO₂/graphene hybrid nanoarrays on Ni foam have been designed and synthesized through a hydrothermal method and post-annealing treatment. Highly conductive graphene sheets were embedded into or coated onto the NiCo₂O₄/NiCoO₂ arrays, which strongly affect influence the morphology and electrochemical performance of hybrid nanoarrays. Under the effect of graphene, the architecture of the NiCo₂O₄/NiCoO₂ consists of cluster-like arrays that are self-assembled from numerous nanoneedles and provides more electroactive sites for the redox reaction. However, without the assistance of graphene, the pure NiCo₂O₄/NiCoO₂ exhibits the morphology of flake-like arrays on the Ni foam. The NiCo₂O₄/NiCoO₂/graphene arrays show an ultrahigh capacity of 1439 C g^-1 at a current density of 1 mA cm^-2, which is far larger than that of the pure NiCo₂O₄/NiCoO₂ flake-arrays (695 C g^-1). Furthermore, even at a high current density of 60 mA cm^-2, the NiCo₂O₄/NiCoO₂/graphene arrays maintain a high gravimetric capacity of 1172 C g^-1 (capacity retention: 81.4%), which indicates an excellent rate capability. Further, the hybrid capacitor shows a maximum energy density of 34.3 Wh kg^-1. The present study suggests that the NiCo₂O₄/NiCoO₂/graphene hybrid arrays have great application potential as a positive electrode for hybrid supercapacitors.     

Improving the electrochemical performance of Ni-rich cathode materials using a fast ion conductor coating of Li2O–B2O3–LiBr

The high-Ni layered metal oxide, LiNi_0.8Co_0.1Mn_0.1O₂ (LNCM811), has received widespread attention in the energy field because of its high specific capacity, but its large-scale applications are hindered due to severe capacity fading. Herein, a uniform and thin Li₂O–B₂O₃–LiBr-glass (LBBrO-glass) coating was deposited on LNCM811 by a liquid-phase coating and thermal treatment method. The experimental results suggested that the LBBrO-glass coating acted as a protective layer that inhibited transition metal dissolution and side reactions, which helped improve the electrochemical properties of LNCM811. Remarkably, after 200 cycles, the 2 wt% coating (LBBrO@LNCM-2) delivered a superior capacity retention of 88.9%, while only 71.8% was obtained for the pristine material (LNCM811). The discharge capacity of LBBrO@LNCM-2 was 163.5 mAh g^?1 at 5C, while it was only 139 mAh g^?1 for the pristine material.     

ZnIn2S4: A promising anode material with high electrochemical performance for sodium-ion batteries

In this study, ZnIn₂S₄ (B-ZIS) and ZnIn₂S₄/C (S-ZIS) composites anode are synthesized using hydrothermal method and followed by ball-milling process. The initial discharge/charge capacities for bare ZnIn₂S₄ (B-ZIS) are 524 and 378 mAh g⁻¹ under a current density of 1 A g⁻¹, which suffers from gradually capacity fading. To improve its cycle stability, high-energy ball-milling process (HEBM) with carbon black is applied to fabricate S-ZIS spherical particles. The as-obtained composite anode exhibits enhanced electrochemical performances not only on cycle stability, but also reversible capacity. The discharge and charge capacity of S-ZIS approach to 823 and 679 mAh g⁻¹ at the first cycle and retain 468 and 459 mAh g⁻¹ after 500 cycles at the high current density of 1 A g⁻¹. Furthermore, ex situ X-ray diffraction (XRD) and ex situ X-ray photoelectron spectroscopy (XPS) techniques are used to monitor the evaluation of crystal structure of B-ZIS during charge and discharge processes. The results indicate that the metallic Zn and In were observed at low potential voltage during sodiation process and successfully converted back to spinel phase at above 0.5 V. The presence of high reversibility nature of B-ZIS may leads to the superior cycling and excellent rate capability of S-ZIS which makes ZnIn₂S₄ a potential anode material of sodium ion batteries.     

Promoting the Li storage performances of Li2ZnTi3O8@Na2WO4 composite anode for Li-ion battery

In this work, a reasonable strategy for the construction of Li₂ZnTi₃O₈@Na₂WO₄ composite was employed to promote the Li storage performances of Li₂ZnTi₃O₈. The Li₂ZnTi₃O₈@Na₂WO₄ composites (5, 10, and 15 wt%) were then prepared by a solution dispersion method. The introduction of Na₂WO₄ does not change the structures of the samples and they show similar morphologies with particle sizes from 100 to 200 nm. Suitable amount of Na₂WO₄ modification effectively improves the electrochemical performance of Li₂ZnTi₃O₈. Li₂ZnTi₃O₈@Na₂WO₄ composites (0, 5, 10, and 15 wt%) deliver the discharge/charge capacities of 137.4/136.4, 164.2/162.3, 189.2/188.1, and 154.5/153.3 mAh g^?1 at 0.5 A g^?1 after 100 cycles, respectively. Li₂ZnTi₃O₈@Na₂WO₄ composites (10 wt%) has the highest reversible capacities among all samples. The Na₂WO₄ shell with an excellent electronic conductivity can reduce electrode polarization, decrease the charge transfer resistance, enhance the Li-ion diffusion coefficient of Li₂ZnTi₃O₈, and then improve the electrochemical kinetics of composites. In addition, the formation of Ti–O bonds at the interface can be helpful for the stabilization of the composite, being beneficial for the improvement of their cycling stabilities. These results reveal that Na₂WO₄ coating is a facile and effective strategy to promote the Li storage performance of Li₂ZnTi₃O₈.     

Binder-free multilayered SnO2/graphene on Ni foam as a high-performance lithium ion batteries anode

The reasonable structure construction of electrode materials with superior performance is desired for the new generation lithium ion batteries (LIBs). Herein, binder-free multilayered SnO₂/graphene (GN) on Ni foam was fabricated via a dip coating method. SnO₂ nanoparticles and GN were alternatively coated on Ni foam to form a sandwich-like structure. The wrapping of GN can raise the conductivity and keep the structural integrality of the binder-free material, preventing structure collapse arised from the volume expansion of SnO₂. Benefiting from the porous Ni foam framework and sandwich-like structure, the SnO₂/GN composite exhibited good rate performance and excellent cycle stability. High capacities of 708 and 609?mAh?g^?1 were achieved at rates of 1 and 2?A?g^?1. Besides, the SnO₂/GN electrode delivered a high capacity of 757?mAh?g^?1 after 500 cycles at 1?A?g^?1.     

Simple solution-combustion synthesis of Fe2TiO5 nanomaterials with enhanced lithium storage properties

The porous Fe₂TiO₅ particles are successfully synthesized through a facile one step solution combustion method. The Fe₂TiO₅ negative materials exhibit remarkable electrochemical performance with discharge capacities of 371.4?mAh g^?1 at the 100 th cycle, and display promising rate stability with discharge capacities 76.6?mAh·g^?1 at a high current density of 3.2?A?g^?1. In addition, the mechanism of electrochemistry reaction is illustrated by the CV, raman and EIS measurements, the irreversible capacity mainly causes from the irreversible lithium insertion at 1.8?V. The results indicate that the one step solution combustion synthesis of porous Fe₂TiO₅ is a promising strategy for developing low-cost and high-performance Ti-based negative materials.     

A ternary MnO/MnTiO3@C composite anode with greatly enhanced cycle stability for Li-ion batteries

Manganese monoxide (MnO) has been widely studied as a potential anode material of Li-ion batteries because of its high specific capacity and abundant raw materials. However, the poor cycling stability of MnO associating to its large volume change during the repeated conversion reaction with Li⁺ has restricted its practical applications. Herein, ternary MnO/MnTiO₃@C composite anode materials are prepared by in situ capturing TiO₂ nanoparticles into sea urchin-like MnO₂ in a mild hydrothermal reaction, followed by resorcinol-formaldehyde (RF) resin coating and thermal treatment. With the strong stabilization effect of the MnTiO₃ component, the optimized ternary MnO/MnTiO₃@C composite anode exhibits greatly enhanced cycling performance as compared to MnO@C. A reversible capacity of 383 mAh g^?1 is preserved after 500 cycles at 1000 mA g^?1. This improved cycle performance can be originated from the stable TiO crystals and the highly reversible amorphous Li_xMnTiO₃ phase generated in the first lithiation process. The reasonably high specific capacity and robust cycle stability enable the ternary MnO/MnTiO₃@C composites to be promising alternative anode materials to graphite for Li-ion batteries.     

A novel “plane-line-plane” nanostructure of the sandwich-like CNTs@SnO2/Ti3C2Tx 3D nanocomposite as a promising anode for lithium-ion batteries

As one of the novel two-dimensional metal carbides, Ti₃C₂T_x has received intense attention for lithium-ion batteries. However, Ti₃C₂T_x has low intrinsic capacity due to the fact that the surface functionalization of F and OH blocks Li ion transport. Herein a novel “plane-line-plane” three-dimensional (3D) nanostructure is designed and created by introducing the carbon nanotubes (CNTs) and SnO₂ nanoparticles to Ti₃C₂T_x via a simple hydrothermal method. Due to the capacitance contribution of SnO₂ as well as the buffer role of CNTs, the as-fabricated sandwich-like CNTs@SnO₂/Ti₃C₂T_x nanocomposite shows high lithium ion storage capabilities, excellent rate capability and superior cyclic stability. The galvanostatic electrochemical measurements indicate that the nanocomposite exhibits a superior capacity of 604.1 mAh g^?1 at 0.05?A?g^?1, which is higher than that of raw Ti₃C₂T_x (404.9 mAh g^?1). Even at 3?A?g^?1, it retains a stable capacity (91.7 mAh g^?1). This capacity is almost 5.6 times higher than that of Ti₃C₂T_x (16.6 mAh g^?1) and 58 times higher than that of SnO₂/Ti₃C₂T_x (1.6 mAh g^?1). Additionally, the capacity of CNTs@SnO₂/Ti₃C₂T_x for the 50th cycle is 180.1 mAh g^?1 at 0.5?A?g^?1, also higher than that of Ti₃C₂T_x (117.2 mAh g^?1) and SnO₂/Ti₃C₂T_x (65.8 mAh g^?1), respectively.     

Ultrathin N‐doped carbon‐coated TiO2 coaxial nanofibers as anodes for lithium ion batteries

The structural optimization of TiO₂ materials has a significance for improving the electrochemical performance since TiO₂ suffers from poor electronic conductivity. For this purpose, ultrathin N‐doped carbon‐coated TiO₂ coaxial nanofibers have been designed and synthesized by a facile electrospinning approach. Microstructure analysis indicates that the TiO₂ nanofibers can be coated by the ultrathin carbon layers. Electrochemical tests reveal that the rate performance and cycling ability of TiO₂@C nanofibers have been enhanced obviously. The TiO₂@C6 nanofibers carbonized at 600°C exhibit superior features with a specific discharge capacity of 284 mAh g^?1 at a current density of 100 mA g^?1 after 100 cycles. Besides improved rate performance of 117 mAh g^?1 at a high current density of 2000 mA g^?1 and excellent cycling stability with only about 0.008% capacity loss per cycle were also obtained in the sample TiO₂@C6 after 500 cycles at the current density of 1000 mA g^?1. Such remarkable performance may be ascribed to the unique one‐dimensional nanofibers as flexible carbon matrix.