Review on Nanoarchitectured Current Collectors for Pseudocapacitors

Abstract

Supercapacitors are of high importance as electrochemical energy storage devices attributing to their outstanding power performance, excellent reversibility and long cycle life. But meanwhile, they suffer from low energy when compared with batteries. Pseudocapacitive materials with a high theoretical capacitance hold a great promise in boosting the energy storage capability for supercapacitors. The emergence of nanoarchitectured current collectors aims to reach their full potentials in charge storage by addressing the challenging issues such as the intrinsically low electrical conductivity, and the sluggish charging–discharging behavior of most pseudocapacitive materials. This review pays particular attention to the advances of nanoarchitectured current collectors for pseudocapacitors. It first gives an introductory background on the design philosophy for nanoarchitectured current collectors based on the charge storage mechanism in pseudocapacitors and also outlines the consequent design considerations, then summarizes the recent achievements in design, fabrication, and utilization of nanoarchitectured current collectors for pseudocapacitors with representative results presented. A comprehensive overview of the strengths and weaknesses of nanoarchitectured current collectors for pseudocapacitors is also highlighted. At the end, future trends and opportunities associated with nanoarchitectured current collectors for pseudocapacitors are discussed.

3D Interdigitated Microsupercapacitors with Record Areal Cell Capacitance

“…The development of microsupercapacitor electrodes with 3D architectures has received increasing interest in recent years due the impressive results using this 3D paradigm shift. Such electrodes rely on the deposition of pseudocapacitive materials, known for their prodigious specific capacitance, onto a high‐surface‐area conductive support . The areal capacitance is improved from one to three orders of magnitude compared to the planar geometry .…”

Advances on three‐dimensional electrodes for micro‐supercapacitors: A mini‐review

“…In the fabrication approach, ordered nanoarchitectures of electrode materials are either self‐assembled spontaneously through an elaborate gas/liquid phase reaction or fabricated by a sophisticated rigid or dynamic template method . Another particularly promising avenue is to fabricate the bulky current collector into nanostructured one first and then conformally deposit a thin layer of pseudocapacitive materials that have high theoretical specific capacitance but low electrical conductivity on it to form heterogeneous electrode (Figure C) . In this fabrication system, the design core lies in the nanostructure of the conductive substrate, which can refer to the preparation techniques of the 3D homogeneous electrode just mentioned.…”

“…As shown in Table , most heterogeneous electrodes are comprised of pseudocapacitive materials shell and 3D conductive scaffold core. Among them, the 3D conductive scaffold facilitating electron transport and meanwhile supporting pseudocapacitive materials is the key in shaping the ultimate electrodes prototype and determining the overall performance of MSCs . For instance, an in‐plane MSC with bicontinuous nanoporous Au architecture (Au NPs) as current collectors and MnO 2 as pseudocapacitive material was reported by Li et al Through further regulating the crystallographic structures of MnO 2 , the internal resistance of the MSC device will be significantly reduced.…”

“…[40][41][42] Another particularly promising avenue is to fabricate the bulky current collector into nanostructured one first and then conformally deposit a thin layer of pseudocapacitive materials that have high theoretical specific capacitance but low electrical conductivity on it to form heterogeneous electrode ( Figure 2C). 43 In this fabrication system, the design core lies in the nanostructure of the conductive substrate, which can refer to the preparation techniques of the 3D homogeneous electrode just mentioned. It is noted that the conductive scaffolds employed in MSCs are not restricted to metallic or carbonaceous materials, but could be silica-based or any other conductive oxides, sulfides, carbides, and nitrides (MXenes) [44][45][46] materials and so forth.…”

3D Exfoliated Carbon Paper toward Highly Loaded Aqueous Energy Storage Applications

“…Apparently, if the specific capacity/ capacitance of a device is normalized including the mass of the passive components, the values would be pretty low for most laboratory devices with low mass loadings. [10,13] To realize the practical applications of an active electrode material, its mass loading should be higher than 10 mg cm À2 . However, highly loaded electrodes with thicker active materials usually suffer from the prolonged charge (ion/ electron) transfer distance, [14] and only a part of the active materials participate in the charge storage.…”