Zhitao Zhang

Novel Electric Double‐Layer Capacitor with a Coaxial Fiber Structure

A coaxial electric double-layer capacitor fiber is developed from the aligned carbon nanotube fiber and sheet, which functions as two electrodes with a polymer gel sandwiched between them. The unique coaxial structure enables a rapid transportation of ions between the two electrodes with a high electrochemical performance. These energy storage fibers are also flexible and stretchable, and can be woven into and widely used for electronic textiles.

Flexible and Stretchable Lithium‐Ion Batteries and Supercapacitors Based on Electrically Conducting Carbon Nanotube Fiber Springs

The construction of lightweight, flexible and stretchable power systems for modern electronic devices without using elastic polymer substrates is critical but remains challenging. We have developed a new and general strategy to produce both freestanding, stretchable, and flexible supercapacitors and lithium-ion batteries with remarkable electrochemical properties by designing novel carbon nanotube fiber springs as electrodes. These springlike electrodes can be stretched by over 300 %. In addition, the supercapacitors and lithium-ion batteries have a flexible fiber shape that enables promising applications in electronic textiles.

Twisted Aligned Carbon Nanotube/Silicon Composite Fiber Anode for Flexible Wire‐Shaped Lithium‐Ion Battery

Twisted, aligned carbon nanotube/silicon composite fibers with remarkable mechanical and electronic properties are designed to develop novel flexible lithium-ion batteries with a high cyclic stability. The core-sheath architecture and the aligned structure of the composite nanotube offer excellent combined properties.

Elastic and Wearable Wire-Shaped Lithium-Ion Battery with High Electrochemical Performance†

A stretchable wire-shaped lithium-ion battery is produced from two aligned multi-walled carbon nanotube/lithium oxide composite yarns as the anode and cathode without extra current collectors and binders. The two composite yarns can be well paired to obtain a safe battery with superior electrochemical properties, such as energy densities of 27 Wh kg(-1) or 17.7 mWh cm(-3) and power densities of 880 W kg(-1) or 0.56 W cm(-3), which are an order of magnitude higher than the densities reported for lithium thin-film batteries. These wire-shaped batteries are flexible and light, and 97 % of their capacity was maintained after 1000 bending cycles. They are also very elastic as they are based on a modified spring structure, and 84 % of the capacity was maintained after stretching for 200 cycles at a strain of 100 %. Furthermore, these novel wire-shaped batteries have been woven into lightweight, flexible, and stretchable battery textiles, which reveals possible large-scale applications.

Electrochromic Fiber‐Shaped Supercapacitors

An electrochromic fiber-shaped super-capacitor is developed by winding aligned carbon nanotube/polyaniline composite sheets on an elastic fiber. The fiber-shaped supercapacitors demonstrate rapid and reversible chromatic transitions under different working states, which can be directly observed by the naked eye. They are also stretchable and flexible, and are woven into textiles to display designed signals in addition to storing energy.

Superelastic Supercapacitors with High Performances during Stretching

A fiber-shaped supercapacitor that can be stretched over 400% is developed by using two aligned carbon nanotube/polyaniline composite sheets as electrodes. A high specific capacitance of approximately 79.4 F g(-1) is well maintained after stretching at a strain of 300% for 5000 cycles or 100.8 F g(-1) after bending for 5000 cycles at a current density of 1 A g(-1). In particular, the high specific capacitance is maintained by 95.8% at a stretching speed as high as 30 mm s(-1).

Super-stretchy lithium-ion battery based on carbon nanotube fiber

Super-stretchy, fiber-shaped lithium-ion batteries with a record strain of 600% are developed by winding two highly aligned carbon nanotube composite fibers. The fiber-shaped battery exhibits high specific capacity, energy density and power density that can be well-maintained under stretching.

A novel “energy fiber” by coaxially integrating dye-sensitized solar cell and electrochemical capacitor

Dye-sensitized solar cell and electrochemical capacitor have been coaxially integrated into a novel “energy fiber” that can simultaneously realize photoelectric conversion and energy storage. A Ti wire substrate modified with perpendicularly aligned titania nanotubes on the surface and horizontally aligned multi-walled carbon nanotube sheet serve as two electrodes in the integrated “energy fiber” device. The “energy fiber” is flexible, and can be woven into various structures such as lightweight textiles to meet the portable facilities in the electronics.

Flexible and stable lithium ion batteries based on three-dimensional aligned carbon nanotube/silicon hybrid electrodes

A three-dimensionally aligned CNT/Si hybrid for flexible and efficient anode has been developed for lithium ion batteries. A delithiation capacity of 2562 mA h g−1 was achieved at a current density of 1 A g−1 with 93% retention after 100 cycles, and the delithiation capacity was retained at 1055 mA h g−1 after 1000 cycles at 5 A g−1. The high specific capacity, cyclic stability and rate performance are ascribed to the aligned CNTs that serve as both conductive pathways and buffer scaffolds to effectively accommodate the volume change of Si in three dimensions. In addition, a stable electrochemical performance is maintained after increasing the areal density of the hybrid anode by over 10 times, indicating great promise for practical applications.

Oriented PEDOT:PSS on aligned carbon nanotubes for efficient dye-sensitized solar cells

Aligned carbon nanotube–oriented poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) composites show an unexpectedly high catalytic activity which greatly exceeds the aligned individual components, the non-aligned composite counterpart, and even conventional platinum. When they are used as counter electrodes in dye-sensitized solar cells, the aligned composites also exhibit a highest energy conversion efficiency of 8.3%. The synergetic interaction between the nanotubes and polymers by aligned organization is the key to this new phenomenon.