Vacuum-Assisted Layer-by-Layer Nanocomposites for Self-Standing 3D Mesoporous Electrodes

Abstract

Electrochemical energy storage devices will play a critical role for efficient storage and reliable on-demand supply to portable electronics, electric and/or plug-in-electric vehicles that entail rapid charging/discharging with long cycle life. The design and assembly of nanoscale materials is critical for developing high performance mesoporous electrodes for energy storage devices that can be scaled-up for manufacturing. To address the challenge of nanostructured electrode development, this work reports a layer-by-layer (LbL) fabrication technique based on electrostatic self-assembly coupled with vacuum assisted filtration. By combining electrostatic interactions with vacuum force, thick electrodes (4–50 μm) of electroactive polyaniline (PANi) nanofibers and oxygen functionalized multiwalled carbon nanotubes (MWNT) are assembled in tens of minutes. The electronic conductivity and mechanical stability are further improved through controlled heat treatment of these electrodes that shows high surface area with interpenetrating networks of nanofibers and nanotubes. Electrochemical measurements reveal high specific capacity of 147 mAh/g originating from the MWNTs and redox active PANi nanofibers that store charges through both electrical double layer and faradaic mechanism with excellent charge/discharge stability over 10,000 cycles. The precise control over the electrode thickness and rapid assembly from this VA-LbL technique show promise for the development of binder-free mesoporous electrodes for next generation electrochemical energy storage devices.

Flexible MXene/Carbon Nanotube Composite Paper with High Volumetric Capacitance

“…Besides, fi lms of several micrometers in thickness could be fabricated in tens of minutes -much faster than in the conventional LbL process. [ 23 ] Our method is thus simpler and faster, yet more effective, compared with LbL, [ 20,23,24 ] even though LbL deposition may lead to more controlled structures and provide further improvements in properties of MXene-based nanocomposites. Spray deposition may also be used to produce similar fi lms in large scale and with a larger thickness.…”

Nanostructured conductive polymers for advanced energy storage

“…Incorporation of carbon nanomaterials can improve the electrical conductivity as well as the mechanical properties of the conductive polymer matrix. Hammond et al 46 adopted a vacuum-assisted layer-by-layer technique to achieve electrodes consisting of PANI nanofibers and multiwall carbon nanotubes (Fig. 7e).…”

Conducting Polymer Paper‐Based Cathodes for High‐Areal‐Capacity Lithium–Organic Batteries

“…[28] Furthermore,o nce the current density was lowered to 0.1 Ag À1 after cycling at successivly increasing current densities (Figure 5e), the specific capacity of 102 mAh g À1 was recovered, thereby demonstratingas table cycling performance. The latter is further supported by the fact that ac apacity of approximately 99 mAh g À1 was found after 150 cycles at ac urrent density of 0.2Ag À 1 (Figure 5f).…”