Author Correction: Scalable synthesis of hierarchically structured carbon nanotube–graphene fibres for capacitive energy storage

Seyedin

Qin

et al. 2019

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applications because they can be integrated into textiles or be made elastic if the fiber electrodes are resilient to bending, stretching, and twisting. [7][8][9][10][11][12] To power electronics, FSCs require high electrical conductivity and high energy storage performance from the fiber electrodes. In hybrid fiber electrodes that comprise of at least one active material and a binder, these electrode properties are dependent upon the amount of active material (loading) and how well the two components are mixed. It is also important that the method of production can be made scalable and continuous. To date, however, a continuous and scalable production of fiber electrodes with high electrical conductivity and energy storage performance remains a challenge. One example of fiber fabrication is via a deposition technique that involves coating of active materials onto a conductive fiber substrate. [13][14][15][16][17][18] This method is simple and scalable to achieve FSC electrodes with active material loading of up to ≈30 wt%. [13,14] Another fiber fabrication example is biscrolling technique, which can trap active materials onto the helical corridors of carbon nanotube (CNT) sheets. [19][20][21][22][23][24][25] This method is suitable for making tens of centimeters long fiber electrodes with very high active material loadings (>90 wt%). Wet-spinning is an industrially viable approach to fiber production and has therefore attracted considerable attention for the fabrication of various FSC electrodes, such as graphene fibers, [26][27][28] CNT fibers, [29][30][31] and conducting polymer fibers. [32][33][34] In wet-spinning composite formulations containing an active material and a binder, the two components must be homogeneously dispersed to achieve "spinnablility" into long continuous fibers. Also, the two components must not limit the function of the other component particularly at high active material loading. The high conductivity and electrochemical performance of the active material must be maintained (for use as electrodes) and the binder must provide durability and flexibility (for continuous production).Ti 3 C 2 T x is one of the growing family of 2D early-transition metal carbides/carbonitrides (MXenes), which shows great promise for application in FSC electrodes. [14,35,36] Besides its high conductivity (up to 9880 S cm −1 ), [37] Ti 3 C 2 T x MXene has an exceptionally high capacitance (up to 1500 F cm −3 ) [38] that comes predominantly from the intercalation/deintercalation of H + and surface redox Fiber-shaped supercapacitors (FSCs) are promising energy storage solutions for powering miniaturized or wearable electronics. However, the scalable fabrication of fiber electrodes with high electrical conductivity and excellent energy storage performance for use in FSCs remains a challenge. Here, an easily scalable one-step wet-spinning approach is reported to fabricate highly conductive fibers using hybrid formulations of Ti 3 C 2 T x MXene nanosheets and poly(3,4-ethylenedioxythiophene):polystyrene sulfonate....

Section: Introductionmentioning

confidence: 99%

Highly Conductive Ti₃C₂T_x MXene Hybrid Fibers for Flexible and Elastic Fiber‐Shaped Supercapacitors

Seyedin

Qin

et al. 2019

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“…It is possible to fulfill the demand of practical applications of microelectronic systems by providing an important complement to microbatteries, which are the major power source for the systems nowadays. [ 3–8 ] Compared to traditional supercapacitors that are mainly evaluated based on the weight of the active material, the footprint area of MSCs is the key parameter, making the areal energy density the most important performance metrics. [ 9 ] The low areal energy density of MSCs is the major problem preventing the development.…”

Section: Introductionmentioning

confidence: 99%

Direct Graphene‐Carbon Nanotube Composite Ink Writing All‐Solid‐State Flexible Microsupercapacitors with High Areal Energy Density

Wang

Wang

et al. 2020

Adv Funct Materials

107

The advancement of miniaturized electronic devices requires the development of high-performance microsupercapacitors. The low areal energy density of microsupercapacitors with the interdigitated architecture is the major challenge hindering the application. Here, a simple method for the scalable fabrication of all-solid-state, flexible microsupercapacitors is demonstrated by direct graphene-carbon nanotube composite ink writing technology. The microsupercapacitors demonstrate good electrochemical performance with a high areal energy density of 1.36 µWh cm -2 and power density of 0.25 mW cm -2 , good cycling stability, and excellent mechanical flexibility. The method developed here sheds light on the simple method of preparing high-performance, all-solid-state, flexible microsupercapacitors in a straightforward and scalable process.

“…Here, we have fabricated the cable‐shaped Li‐S batteries based on nitrogen‐doped carbon/carbon nanotube/sulfur (NCNT/S) yarn cathode and further investigated its electrochemical performance. First, CNT has outstanding mechanical and conductive properties and polyaniline (PANI) is a suitable choice as a source of nitrogen doping. The polyaniline/carbon nanotube (PANI/CNT) composite yarns were synthesized by the wet‐spinning approach ( Figure a).…”

mentioning

confidence: 99%

Cable‐Shaped Lithium–Sulfur Batteries Based on Nitrogen‐Doped Carbon/Carbon Nanotube Composite Yarns

Yuan

Yang

et al. 2019

Macro Materials & Eng

investigated carefully due to their strong mechanical properties and comprehensive orientational flexibility of one-dimensional (1D) architecture, [22] and 1D cable type devices can be bent into various shape and applied to electronic fabrics. [23] Cableshaped energy storage devices have been studied mostly due to their importance in electronic fabrics.The current cable-shaped lithium-ion batteries and supercapacitors, [24] however, cannot fully meet the requirements of practical applications due to the low energy density of electrode materials. [25] Lithium-sulfur (Li-S) batteries [26] with a theoretical energy density of 2600 Wh kg −1 and a specific capacity of 1675 mAh g −1 are emerging as a promising secondary battery system. [27] Sulfur as the active material possesses the advantages of low cost, abundant resources, and environmentally friendly behavior. [28,29] Although there are many reports on traditional flexible Li-S batteries, [30] the cable-shaped Li-S batteries with yarn structure cathode have been seldom reported up to date. Recently, typical cable-type Li-S batteries with high areal capacity and good flexibility were reported by Peng group. [31] They fabricated a device using a composite yarn cathode consisted of graphene oxide (GO)/mesoporous carbon (CMK-3)/ sulfur and current collector of carbon nanotube (CNTs) yarns made by chemical vapor deposition (CVD). The preparation of pure CNTs by CVD is complicated and costly. A simple method to fabricate the yarn cathode based on wet-spinning was reported by Kim et al. [22] Despite the better mechanical performance with the reduced graphene oxide/CNT/S cathode, the electrochemical performance of composite yarn cathode still needs to be improved for cable-shaped Li-S batteries. Thus, it is necessary to achieve yarn structure electrode with excellent electrochemical stability by simple approaches to assemble the cable-shaped Li-S batteries.Here, we have fabricated the cable-shaped Li-S batteries based on nitrogen-doped carbon/carbon nanotube/sulfur (NCNT/S) yarn cathode and further investigated its electrochemical performance. First, CNT [32] has outstanding mechanical and conductive properties and polyaniline (PANI) is a suitable choice as a source of nitrogen doping. The polyaniline/carbon nanotube (PANI/CNT) composite yarns were synthesized by the wetspinning approach (Figure 1a). The pure PANI/CNT yarns are shown in Figure 1b. To enhance the conductivity of PANI/CNT Cable-Shaped Batteries The research on flexible and wearable devices has attracted extensive attention in the last few years. Lithium-sulfur (Li-S) batteries are regarded as a promising option because of their high theoretical capacity and energy density. Here, cable-shaped Li-S batteries are developed based on a nitrogendoped carbon/carbon nanotube/sulfur (NCNT/S) composite cathode and lithium metal anode. The carbon nanotube (CNT) yarns with high conductivity and an appropriate amount of doped nitrogen are synthesized by wet-spinning followed by a carbonization process, and further act a...