Energy storage systems including supercapacitors and lithium ion batteries typically appear in a rigid plate which is unfavorable for many applications, especially in the fi elds of portable and highly integrated equipments which require small size, light weight, and high fl exibility. [1][2][3] As a result, fl exible supercapacitors and batteries mainly in a fi lm format have been widely investigated, while wire-shaped energy storage devices are rare. [ 4 , 5 ] However, compared with the conventional planar structure, a wire device can be easily woven into textiles or other structures to exhibit unique and promising applications. The limitation is originated from the much stricter requirement for the electrode such as a combined high fl exibility and electrochemical property in wire-shaped devices. [ 6 , 7 ] It remains challenging but becomes highly desired to obtain wire-shaped supercapacitors and batteries with high performances.On the other hand, due to the unique structure and remarkable mechanical and electrical properties, carbon nanotubes (CNTs) have been widely studied as electrode materials in conventional planar energy storage devices. [ 8 , 9 ] However, CNTs are generally made in a network format in which the produced charges had to cross a lot of boundaries with low effi ciencies. It is critically important to improve the charge transport in CNT materials. [8][9][10][11][12][13] Herein, we have developed wire-shaped micro-supercapacitors and micro-batteries with high performances by using aligned multi-walled carbon nanotube (MWCNT) fi bers as electrodes. The micro-supercapacitor wire was fabricated by twisting two aligned MWCNT fi bers and showed a mass specifi c capacitance of 13.31 F/g, area specifi c capacitance of 3.01 mF/cm 2 , or length specifi c capacitance of 0.015 mF/cm at 2 × 10 − 3 mA (1.67 A/g). The wire-shaped battery was produced by twisting an aligned MWCNT fi ber and a lithium wire which functioned as positive and negative electrodes, respectively. The specifi c capacity was calculated as 94.37 mAh/cm 3 or 174.40 mAh/g at 2 × 10 − 3 mA. The energy and power densities in both supercapacitors and batteries could be further greatly improved by incorporation of MnO 2 nanoparticles into MWCNT fi bers. For instance, the charge and discharge energy densities achieved 92.84 and 35.74 mWh/cm 3 while the charge and discharge power densities were 3.87 and 2.43 W/cm 3 at 2 × 10 − 3 mA in the wire-shaped micro-battery.Spinnable MWCNT arrays were fi rst synthesized by chemical vapor deposition, and aligned MWCNT fi bers could then be spun from the array with controlled diameters from 2 to 30 μ m and lengths up to 100 m. Figure S1a shows a typical scanning electron microscopy (SEM) image of MWCNT fi ber with uniform diameter of 20 μ m. Figure 1 a further shows that MWCNTs are highly aligned in the fi ber, which enables high tensile strengths up to 1.3 GPa and high electrical conductivities of 10 3 S/cm. Therefore, the MWCNT fi bers had been further used as electrodes to deposit MnO 2 on the MWCN...

Light my wire: Aligned carbon nanotube (CNT) fibers are wrapped around a TiO2 nanowire that is several centimeters long. Treating the ends of the nanotube wire with a light‐sensitive dye and an electrolyte, creates photoelectric‐conversion and energy‐storage regions in the same device (see scheme). The “wire” shows a high overall photoelectric conversion and storage efficiency of 1.5 %.

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Metal wires suffer from corrosion in fiber-shaped dye-sensitized solar cells (DSSCs). We report herein that stable, ultrastrong, and highly flexible aligned carbon nanotube fibers can be used not only as catalytic counter electrodes but also as conductive materials to support dye-loaded TiO(2) nanoparticles in DSSCs. The power conversion efficiency of this fiber solar cell can achieve 2.94%. These solar power fibers, exhibiting power conversion efficiency independent of incident light angle and cell length, can be woven into textiles via a convenient weaving technology.

Polyaniline composite films incorporated with aligned multi-walled carbon nanotubes (MWCNTs) are synthesized through an easy electrodeposition process. These robust and electrically conductive films are found to function as effective electrodes to fabricate transparent and flexible supercapacitors with a maximum specific capacitance of 233 F/g at a current density of 1 A/g. It is 36 times of bare MWCNT sheet, 23 times of pure polyaniline and 3 times of randomly dispersed MWCNT/polyaniline film under the same conditions. The novel supercapacitors also show a high cyclic stability.

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Bioremediation is a cost-effective and eco-friendly approach to decontaminate soils polluted by petroleum hydrocarbons. However, this technique usually requires a long time due to the slow degradation rate by bacteria. By applying U-tube microbial fuel cells (MFCs) designed here, the degradation rate of petroleum hydrocarbons close to the anode (<1 cm) was enhanced by 120% from 6.9 ± 2.5% to 15.2 ± 0.6% with simultaneous 125 ± 7 C of charge output (0.85 ± 0.05 mW/m(2) , 1 kΩ) in the tested period (25 days). Hydrocarbon fingerprint analysis showed that the degradation rate of both alkanes and polycyclic aromatic hydrocarbons (PAHs) was accelerated. The decrease of initial water content from 33% to 28% and 23% resulted in a decrease on charge output and hydrocarbon degradation rate, which could be attributed to the increase of internal resistance. A salt accumulation was observed in each reactor due to the evaporation of water from the air-cathode, possibly inhibited the activity of exoelectrogenic bacteria (EB) and resulted in the elimination of the current at the end of the tested period. The number of hydrocarbon degradation bacteria (HDB) in soil close to the anode increased by nearly two orders of magnitude in the MFC assisted system (373 ± 56 × 10(3)  CFU/g-soil) than that in the disconnected control (8 ± 2 × 10(3)  CFU/g-soil), providing a solid evidence for in situ biostimulation of HDB growth by colonization of EB in the same system.

Polyaniline composite fibers incorporated with aligned multi-walled carbon nanotubes are first synthesized with high mechanical strength and electrical conductivity through an easy electrodeposition process, and two robust composite fibers have then been twisted to produce microsupercapacitor wires with a specific capacitance of 274 F g À1 or 263 mF cm À1 . These energy storage wires are light-weight, flexible, strong and weavable for promising applications in various fields.