Lithium Storage in Ordered Mesoporous Carbon (CMK‐3) with High Reversible Specific Energy Capacity and Good Cycling PerformanceCarbonaceous materials with high specific energy capacity are prime candidates for applications in rechargeable lithium batteries. The authors report the synthesis and characterization of ordered mesoporous carbon (CMK‐3), synthesized using ordered silica as a template, with high reversible specific capacity and good charge–discharge cycle characteristics. The performance of CMK‐3 is compared with that of carbon nanotubes, and its superiority is suggested to be related to the three‐dimensional ordered structure of CMK‐3.
Graphene Platelets and Their Polymer Composites: Fabrication, Structure, Properties, and ApplicationsGe Shi, Sherif Araby, Christopher T. Gibson et al.|Advanced Functional Materials|2018 Abstract Graphene oxide is extensively compounded with polymers toward a wide variety of applications. Less studied are few‐layer or multi‐layer highly crystalline graphene, both of which are herein named as graphene platelets. This article aims to provide the most recent advancements of graphene platelets and their polymer composites. A first focus lies on cost‐effective fabrication strategies of graphene platelets – intercalation and exfoliation – which work in a relative mass scale, e.g., 5.3 g h −1 . As no heavy oxidization is involved, the platelets have high crystalline integrity, e.g., C:O ratio over 8.0, with thicknesses 2–4 nm and lateral dimension up to a few micrometers. Through carefully selecting the solvent for dispersion and the molecules for surface modification, graphene platelets can be liquid‐processable, enabling them to be printed, coated, or compounded with various polymers. A purpose‐designed experiment is undertaken to unravel the effect of reasonable ultrasonication time on the platelet thickness. Typical polymer/graphene platelet composites are critically examined for their preparation, structure, and applications such as thermal management and flexible/stretchable electronic devices. Perspectives on the limitations, current challenges, and future prospects for graphene platelets and their polymer composites are provided.
Synthesis of MnO<sub>2</sub> Nanoparticles Confined in Ordered Mesoporous Carbon Using a Sonochemical MethodShenmin Zhu, Haoshen Zhou, Mitsuhiro Hibino et al.|Advanced Functional Materials|2004 Abstract A sonochemical method has been successfully used in order to incorporate MnO 2 nanoparticles inside the pore channels of CMK‐3 ordered mesoporous carbon. Modification of the intrachannel surfaces of CMK‐3 to make them hydrophilic enables KMnO 4 to readily penetrate the pore channels. At the same time, the modification changes the surface reactivity, enabling the formation of MnO 2 nanoparticles inside the pores of CMK‐3 by the sonochemical reduction of metal ions. The resultant structures were characterized by X‐ray diffraction (XRD), nitrogen adsorption, and transmission electron microscopy (TEM). CMK‐3 with 20 wt.‐% loading of MnO 2 inside CMK‐3 delivered an improved discharge performance of 223 mA h g –1 at a relatively high rate of 1 A g –1 . Almost no decrease in specific capacity is observed for the second cycle, and a discharge capacity of more than 165 mA h g –1 is retained after 100 cycles. This is attributed to the nanometer‐sized MnO 2 formed inside CMK‐3 and the high surface area of the mesopores (3.1 nm) in which the MnO 2 nanoparticles are formed.