Controlling and optimizing the morphology and microstructure of 3D interconnected activated carbons for high performance supercapacitors

Abstract

For an active electrode material, the morphology, microstructure and the effective specific surface area derived from them, have a dominant effect for the high performance supercapacitors. In this study, 3D interconnected activated carbons with controlled and optimized morphologies and porous structures were prepared from accessible carbon source and graphene oxide by a hydrothermal carbonization and following an activation method. Through optimizing the ratios of the precursors and reaction conditions, an electrode material with excellent specific surface area of 2318 m2 g−1, meso-/macro-pore ratio of 63.2% (meso-/macro-pore volume reached to 0.83 cm3 g−1), as well as an outstanding electrical conductivity of 46.6 S m−1, was obtained. The materials exhibit superior double-layer capacitive performances on a symmetric supercapacitor, delivering superior specific capacitance of 157 F g−1 in organic electrolyte system at current density of 0.5 A g−1, excellent energy density of 37.6 W h kg−1 with a power density of 7.1 kW kg−1 and good cycling stability of capacitance retention of 94% over 7000 cycles. These results offer a practical method to prepare the desired carbon electrode materials with controlled morphology and structure for high efficiency electrochemical energy storage devices.

Room temperature control of grain orientation via directionally modulated current pulses

“…Controlling the microstructure to tailor the properties of materials has always been a highly desired capability in materials science and engineering. The customization of materials properties caters to specific performance needs and has led to innovative advancements in various industries [1,2]. Typically, microstructure control means manipulating grain size, crystal orientation, low-angle grain boundaries (LAGBs) density, etc, which can enhance mechanical and electrical properties such as strength, toughness, and electrical conductivity [3,4].…”

Enhancing the energy storage performances of metal–organic frameworks by controlling microstructure

“…17,18 While signicant work has examined the impact of pore structure on the capacitive performances of porous carbon materials and other families of electrically conductive MOFs, little work has been performed to understand how morphology impacts the performances of layered MOFs in supercapacitors. [19][20][21][22] This has hindered the development of layered MOFs for energy storage applications, with potential performance gains to be had from optimising the microstructure. One notable exception is the work of Dincȃ et al, which studied the inuence of sample microstructure on the capacitive performance of Ni 3 (HITP) 2 (HITP ¼ 2,3,6,7,10,11hexaiminotriphenylene) in three-electrode cells with 1 M KOH in water electrolyte.…”