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Abstract: The synthesis of graphene oxide (GO) sheets with controlled size on a large scale was developed using chemical exfoliation by simply controlling the oxidation and exfoliation procedure. The GO samples prepared under different conditions, which all have excellent water dispersion, are characterized by thermal gravimetric analysis, Ultraviolet–visible spectroscopy, X-ray diffraction and atomic force microscopy. It is found that as longer oxidation times and more oxidants are used, the mean size of the GO sheets, which has a Gaussian distribution, decreases from ∼59,000 to ∼550nm2. [Copyright &y& Elsevier]

• 3D porous and highly conductive thick electrodes were designed by 3D printing. • 3D-printed thick electrodes were constructed by using nanocomponents-based hybrid ink. • 3D-printed electrodes show both high areal capacity and rate performance. • This strategy represents a simple process for the preparation of thick electrodes. The development of robust performing lithium-ion batteries (LIBs) with high areal capacity is a challenge that persists to date. One commonly used strategy to increase areal capacity is increasing the thickness of the battery electrodes. However, the practical application of these thick electrodes is hindered thanks to the fundamental issues of incomplete electrolyte infiltration, poor mechanical properties, and slow charge and ion transport. Herein, a new method is presented wherein a thick electrode is constructed by 3D printing a highly-conductive and hierarchical network of silver nanowires (AgNWs), graphene and Li 4 Ti 5 O 12 together as a mixed functional ink. The amalgamation of highly conductive AgNW network, interconnected 3D graphene scaffold, and hierarchical porous structure can allow the 3D-printed electrode to demonstrate much improved charge and ion transport, and to alleviate internal stresses during the charging and discharging process even under ultrahigh thickness state. As a result, the LIBs utilizing these thick electrodes have a rate capability of 121 mAh g−1 at 10C, high areal capacities up to 4.74 mAh cm−2, and stable cycling performance (capacity retention of ~95.5% after 100 cycles). These performance metrics provide a route for a new design strategy using thick electrodes for high-performance energy storage devices. [ABSTRACT FROM AUTHOR]

Strong terahertz‐response material which exhibits both excellent terahertz shielding and stealth performance is promising in practical applications of terahertz technology. Here, ultralight graphene foam (GF) and multiwalled carbon nanotubes/multiwalled graphene foam (MGF) have been first demonstrated to achieve both superior terahertz shielding and stealth performance due to the dominant absorption loss with negligible reflection. The terahertz shielding effectiveness values of GF and MGF, both 3 mm thick, reach up to 74 and 61 dB. Meanwhile, their average terahertz reflection loss values are achieved up to 23 and 30 dB, respectively, which are the best results in existing broadband terahertz shielding/stealth materials. Importantly, their qualified absorption bandwidths (reflection loss value larger than 10 dB) cover the entire measured frequency band of 0.1–1.6 THz. Furthermore, the quantitative relationships between the terahertz shielding effectiveness, reflection loss, and material parameters are accurately established, which should facilitate the material design for terahertz shielding and stealth. Comprehensively considering the important indicators of density, bandwidth, and intensity, the specific average terahertz shielding coefficient and the specific average terahertz absorption performance are achieved up to 1.1 × 105 and 3.6 × 104 dB cm3 g−1, respectively, which is over thousands of times larger than other kinds of materials reported previously. Graphene‐based composites combining both outstanding terahertz shielding and stealth performance are first demonstrated. The composites present maximum average shielding effectiveness of 74 dB and reflection loss value of 30 dB in the whole measured band due to the dominant absorption loss with negligible reflection (<0.05 dB). Quantitative relationships between terahertz shielding/stealth properties and material parameters are also accurately established. [ABSTRACT FROM AUTHOR]