N‐doped carbon nanotube sponges and their excellent lithium storage performances

Abstract

Preparation, analysis and lithium storage performance of a series of nitrogen‐doped carbon nanotube sponges (CNX) is presented in this work. The synthesis was performed using an aerosol‐assisted chemical vapor deposition (AACVD) in a bi‐sprayer system by using various carbon and nitrogen precursors made of mixtures of benzylamine with toluene, urea, pyridine and 1,2‐dichlorbenzene, with ferrocene as catalyst. A series of physico‐chemical analysis techniques are used to characterize the composition and the morphology of the obtained materials, and a correlation of these with the lithium storage performances is attempted. The samples reveal an interconnected core‐shell CNX fiber morphology with a CNT‐core surrounded by an amorphous carbon shell. Appealing lithium storage performances are attained, while also considering aspects of safety, low potential, and long‐term cycling stability. The best performing sponges display a high specific capacity (223 mAh g−1) when cycled in a practically relevant voltage window (0.01–1V vs. Li), high first cycle (90%) and long‐term cycling (99.3%) coulombic efficiencies and excellent capacity retention after 1500 cycles. This study further analyses the interplay between the morphology and the physico‐chemistry of nitrogen‐doped carbon nanotube materials for Lithium storage and provides guidelines for future developments.

Covalent Organic Frameworks as Emerging Battery Materials

“…[4] The carbon dioxide produced by COF materials in the process of organic material extraction and preparation, battery assembly and recycling can be absorbed and utilized by plants, reflecting excellent recyclability and renewability. [5] Since the report of COF-1, the research of COF materials has been carried out rapidly and exciting progress has been made worldwide. [6] COFs are porous organic crystalline materials connected by covalent bonds.…”

Magnetic field induced alignment of macroradical epoxy for enhanced electrical properties

“…1 However, its conductivity can be increased when mixed with certain ionic liquids 2 or by grafting with carbon nanoparticles. 3,4 The inherent molecular design that resulted in the highest reported conductivity for poly(4-glycidyloxy-2,2,6,6-tetramethylpiperidine-1-oxyl) (PTEO) required a dilution of the radical sites relative to many other radicals in the polymer, in order to achieve charge transfer efficiently. In such a material, the hopping transport of electronic carriers was presumably assisted by segmental motion, 5 even though PTEO required specific treatment and the domain size was smaller than 1 micron.…”

“…Their potential for charge storage applications drove studies on redox-active polymers capable of self-reorganization to produce highly anisotropic structures. 4,13 A mature yet simple amino-epoxide chemistry was recently employed to prepare a non-conjugated radical thermoset in a rigid, 3D motif. 14 This novel macroradical epoxy exhibited a p-type conductivity with hole mobility (m h ) in the 10 À6 cm 2 V À1 s À1 range, which is already in the realm of traditional conjugated semiconducting polymers.…”

“…Their potential for charge storage applications drove studies on redox-active polymers capable of self-reorganization to produce highly anisotropic structures. 4,13…”

Direct synthesis of nitrogen-doped narrow-diameter carbon nanotubes through floating-catalyst chemical vapor deposition with high hydrogen flow rate

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