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Flexible energy storage devices have received tremendous attention with the rapid development of wearable electronics. Commercial lithium‐ion batteries are gradually reaching their theoretical capacity, which is still unable to meet the requirements of flexible electronics for high energy density. Lithium–sulfur batteries with a high theoretical capacity of 1675 mA h g−1 are regarded as the most promising next‐generation high‐energy‐density power source. Herein, the various recent efforts in the development of lithium–sulfur batteries based on carbonaceous and polymer materials are summarized, with an emphasis on flexible systems. Flexible lithium–sulfur batteries based on carbonaceous materials such as carbon nanotubes, graphene, and carbonized polymer or biomass, polymers, and solid‐state electrolytes are reviewed. Finally, the challenges and further improvements of lithium–sulfur batteries are summarized and prospected.

Inspired by rich physics and functionalities of graphenes, scientists have taken an intensive interest in two-dimensional (2D) crystals of h-BN (analogue of graphite, so-called “white” graphite). Recent calculations have predicted the exciting potentials of BN nanoribbons in spintronics due to tunable magnetic and electrical properties; however no experimental evidence has been provided since fabrication of such ribbons remains a challenge. Here, we show that few- and single-layered BN nanoribbons, mostly terminated with zigzag edges, can be produced under unwrapping multiwalled BN nanotubes through plasma etching. The interesting stepwise unwrapping and intermediate states were observed and analyzed. Opposed to insulating primal tubes, the nanoribbons become semiconducting due to doping-like conducting edge states and vacancy defects, as revealed by structural analyses and ab initio simulations. This study paves the way for BN nanoribbon production and usage as functional semiconductors with a wide range of applications in optoelectronics and spintronics. [ABSTRACT FROM AUTHOR]

Herein the recent experiments performed by the authors on fabricated multi-walled BN nanotubes and monoatomic BN graphene-like nanosheets are reviewed. The results are presented in several sections, namely: (i) method for high-yield synthesis of thin, defect-free BN nanotubes of only a few-layers, with external diameters below 10 nm; (ii) verification of BN nanotube piezoelectrical behavior and its electrically-induced thermal decomposition under combined resistive heating and electrical charging in a transmission electron microscope; (iii) the first direct measurements of the true tensile strength and Young's modulus of BN nanotubes, using newly developed nanotensile tests inside an electron microscope; the measured values were found to be ∼30 GPa and ∼900 GPa, respectively; and (iv) diverse kinetic processes taking place within the prepared monoatomic BN sheets (so-called 'white graphenes') affiliated with intensive knock-on B and N atom displacements under high energy electron beam irradiation in an aberration-corrected medium-voltage high-resolution transmission electron microscope. [ABSTRACT FROM AUTHOR]