%0 Journal Article
%T Epitaxial Welding of Carbon Nanotube Networks for Aqueous Battery Current Collectors
%J -
%D 2018
%R https://doi.org/10.1021/acsnano.7b08584
%X Carbon nanomaterials are desirable candidates for lightweight, highly conductive, and corrosion-resistant current collectors. However, a key obstacle is their weak interconnection between adjacent nanostructures, which renders orders of magnitude lower electrical conductivity and mechanical strength in the bulk assemblies. Here we report an ¡°epitaxial welding¡± strategy to engineer carbon nanotubes (CNTs) into highly crystalline and interconnected structures. Solution-based polyacrylonitrile was conformally coated on CNTs as ¡°nanoglue¡± to physically join CNTs into a network, followed by a rapid high-temperature annealing (>2800 K, overall ¡«30 min) to graphitize the polymer coating into crystalline layers that also bridge the adjacent CNTs to form an interconnected structure. The contact-welded CNTs (W-CNTs) exhibit both a high conductivity (¡«1500 S/cm) and a high tensile strength (¡«120 MPa), which are 5 and 20 times higher than the unwelded CNTs, respectively. In addition, the W-CNTs display chemical and electrochemical stabilities in strong acidic/alkaline electrolytes (>6 mol/L) when potentiostatically stressing at both cathodic and anodic potentials. With these exceptional properties, the W-CNT films are optimal as high-performance current collectors and were demonstrated in the state-of-the-art aqueous battery using a ¡°water-in-salt¡± electrolyte
%U https://pubs.acs.org/doi/10.1021/acsnano.7b08584