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For carbon nanotube-based electronics to achieve their full performance potential, it is imperative to minimize the contact resistance between macroscale metal contacts and the carbon nanotube (CNT) nanoelectrodes. We have developed a three-dimensional electrode platform that consists of carbon nanofibers (CNFs) that are directly grown on a metal contact, such as copper (Cu). Carbon nanofiber morphology can be tailored by adjusting the annealing time of a thin electrochemically deposited nickel catalyst layer on copper. We demonstrate that increasing the annealing time increases the amount of copper infused into the nickel catalyst layer. This reduces the carbon deposition rate, and consequently a more well-defined CNF 3D architecture can be fabricated. This direct growth of CNFs on a Cu substrate yields an excellent electron transfer pathway, with contact resistance between CNFs and Cu being comparable to that of a Cu-Cu interface. Furthermore, the excellent bonding strength between CNFs and Cu can be maintained over prolonged periods of ultrasonication. The porous 3D platform affixed with intertwined CNFs allows facile surface functionalization. Using a simple solution soaking procedure, the CNF surface has been successfully functionalized with iron(II) phthalocyanine (FePc). FePc functionalized CNFs exhibit excellent oxygen reduction capability, equivalent to platinum-carbon electrodes. This result demonstrates the technological promise of this new 3D electrode platform that can be exploited in other applications that include sensing, battery, and supercapacitors.

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A unique way of robustly integrating an elastomer film onto a graphitic anode and then post process it into a solid‐state electrolyte for lithium‐ion battery applications is reported. The mutual solvability of the elastomer and the binder of the graphitic anode (carboxymethyl cellulose, (CMC)) in dimethylformamide facilitates the fusion of the two heterogeneous layers. Dimensional dynamics evolved during the integrated elastomer conversion into a solid electrolyte by liquid electrolyte uptake reveal a notable preferential uniaxial elongation along the normal plane. In contrast, the non‐integrated counterpart elongates along the transversal axis. These elastomer exhibits high ionic conductance (≈10–2 S cm−1). Half‐cells constructed with our electrolyte integrated electrode exhibit magnificent reduction and oxidation (REDOX) behavior. The efficient charge transfer across the snugly confined semi‐solid electrolyte/electrode interface layer leads to a high rate capability of 0.31 mAh cm−2 (41 mAh g−1) at 2 C which is double that of a graphitic conventional half‐cell. Unlike regular graphitic electrodes which degrade over time, this electrode remains robust, thanks to its propensity to retain its inherent elasticity. This work demonstrates a facile and scalable paradigm, in fabrication of flexible electrolytes that can easily be integrated to 3D devices and opens opportunities for developing, structurally conformable batteries of varied geometries.

Processability remains a fundamental issue for the implementation of conducting polymer technology. A simple synthetic route towards processable precursors to conducting polymers (main chain and side chain) was developed using commercially available materials. These soluble precursor systems were converted to conjugated polymers electrochemically in aqueous media, offering a cheaper and greener method of processing. Oxidative conversion in aqueous and organic media each produced equivalent electrochromics. The precursor method enhances the yield of the electrochromic polymer obtained over that of electrodeposition, and it relies on a less corruptible electrolyte bath. However, electrochemical conversion of the precursor polymers often relies on organic salts and solvents. The ability to achieve oxidative conversion in brine offers a less costly and a more environmentally friendly processing step. It is also beneficial for biological applications. The electrochromics obtained herein were evaluated for electronic, spectral, and morphological properties.