Guozhen Guan

Flexible and Weaveable Capacitor Wire Based on a Carbon Nanocomposite Fiber

A flexible and weaveable electric double-layer capacitor wire is developed by twisting two aligned carbon nanotube/ordered mesoporous carbon composite fibers with remarkable mechanical and electronic properties as electrodes. This capacitor wire exhibits high specific capacitance and long life stability. Compared with the conventional planar structure, the capacitor wire is also lightweight and can be integrated into various textile structures that are particularly promising for portable and wearable electronic devices.

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.

Aligned Carbon Nanotube Sheets for the Electrodes of Organic Solar Cells

Aligned carbon nanotube sheets are developed as a new family of electrodes to fabricate dye-sensitized solar cells. The energy conversion efficiency of the resulting cell is higher than the randomly dispersed carbon nanotube film and comparable with the platinum. Novel and flexible solar cells can be easily made from such carbon nanotube sheets with high potentials.

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).

Smart, Stretchable Supercapacitors

Smart supercapacitors are developed by depositing conducting polymers onto aligned carbon-nanotube sheets. These supercapacitors rapidly and reversibly demonstrate color changes in response to a variation in the level of stored energy and the chromatic transitions can be directly observed by the naked eye.

Self-Healable Electrically Conducting Wires for Wearable Microelectronics†

Electrically conducting wires play a critical role in the advancement of modern electronics and in particular are an important key to the development of next-generation wearable microelectronics. However, the thin conducting wires can easily break during use, and the whole device fails to function as a result. Herein, a new family of high-performance conducting wires that can self-heal after breaking has been developed by wrapping sheets of aligned carbon nanotubes around polymer fibers. The aligned carbon nanotubes offer an effective strategy for the self-healing of the electric conductivity, whereas the polymer fiber recovers its mechanical strength. A self-healable wire-shaped supercapacitor fabricated from a wire electrode of this type maintained a high capacitance after breaking and self-healing.

A Gum‐Like Lithium‐Ion Battery Based on a Novel Arched Structure

Stretchable lithium-ion batteries (LIBs) consisting of an arch structure and a stretchable anode and cathode are developed using a general strategy. The LIB maintains a remarkable and stable electrochemical performance after hundreds of stretching cycles at a strain of 400%. Compared with other stretchable LIBs, which stretch at the device level, but whose components (electrodes) remain rigid, the component-level stretchability is here the design key to the LIBs highly stable performance.

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.

An Aligned and Laminated Nanostructured Carbon Hybrid Cathode for High‐Performance Lithium–Sulfur Batteries

An aligned and laminated sulfur-absorbed mesoporous carbon/carbon nanotube (CNT) hybrid cathode has been developed for lithium-sulfur batteries with high performance. The mesoporous carbon acts as sulfur host and suppresses the diffusion of polysulfide, while the CNT network anchors the sulfur-absorbed mesoporous carbon particles, providing pathways for rapid electron transport, alleviating polysulfide migration and enabling a high flexibility. The resulting lithium-sulfur battery delivers a high capacity of 1226 mAh g(-1) and achieves a capacity retention of 75% after 100 cycles at 0.1 C. Moreover, a high capacity of nearly 900 mAh g(-1) is obtained for 20 mg cm(-2), which is the highest sulfur load to the best of our knowledge. More importantly, the aligned and laminated hybrid cathode endows the battery with high flexibility and its electrochemical performances are well maintained under bending and after being folded for 500 times.