Boosting Areal Capacitance and Energy Density of a Flexible Supercapacitor Based on High-Mass-Loading Layered Double Hydroxides

Abstract

Flexible electrodes with a high density of active material loading as well as abundant charge transfer channels are crucial for high-performance wearable energy storage devices, and their fabrication also remains a great challenge. In this work, we report a hierarchical binder-free flexible electrode based on carbon nanosheets and a high-mass-loading CoNi-layered double hydroxide (11.8 mg cm–2) core–shell structure on the carbon clothe support (denoted as CC/CNs@CoNi-LDH). The as-synthesized CC/CNs@CoNi-LDH electrode delivers a superior mass energy density of 69.8 W h kg–1, a power density of 4.3 kW kg–1, and excellent stability with a retention of 91.1% of the initial capacitance even after 10,000 cycles. Moreover, ex situ techniques including X-ray photoelectron spectroscopy, X-ray diffraction, and Fourier transform infrared spectroscopy were carried out to identify the structure evolution and the electrochemical reaction mechanism of CC/CNs@CoNi-LDH. This work suggests a facile route to construct a binder-free electrode with a high-mass-loading, which is promising for the development of energy storage systems.

Facile Assembly of Hybrid Micro-Supercapacitors for a Sunlight-Powered Energy Storage System

“…The core-level spectrum of Ni 2p (Figure d) could be curve-fitted with two peaks at 855.9 and 873.5 eV attributed, respectively, to Ni 2p3/2 and Ni 2p1/2 along with two satellite peaks, inferring that the valence state of Ni element is +2 Figure e depicts the core-level spectrum of Co 2p of CoNi LDHs-2@CNTs comprising two main peaks located at 781.3 and 797.1 eV, ascribed to Co 2p3/2 and Co 2p1/2 , respectively, along with two satellite components, signifying the existence of Co­(II) …”

“…33 Figure 3e depicts the core-level spectrum of Co 2p of CoNi LDHs-2@CNTs comprising two main peaks located at 781.3 and 797.1 eV, ascribed to Co 2p3/2 and Co 2p1/2 , respectively, along with two satellite components, signifying the existence of Co(II). 26 Moreover, the morphologies of the negative CNTs and positive CoNi LDHs@CNT electrodes of the as-prepared MSCs were investigated by scanning electron microscopy (SEM). As illustrated in Figure 4a,b, the spacing distance between two electrodes is 500 μm, and the width of one electrode is 1 mm with regular shapes.…”

“…were also applied for the construction of MSCs. Among the battery-type materials, layered double hydroxides (LDHs) are extensively investigated in SC application owing to their beneficial attributes, such as high redox activity, unique two-dimensional layered structure, and environmentally friendly nature. − Therefore, their application potential in MSCs deserves attention to explore the possibility to improve the electrochemical performance of the MSC devices. However, the literature on LDH application for MSC assembly is scarce.…”

Heterostructured Co-NTC@Co3S4 as an anode material for asymmetric pseudocapacitors

“…The synthesis process refers to the published article. 31 In short, 2.18 g Co(NO 3 ) 2 was ultrasonically dispersed in 150 mL of deionized water, and another 150 mL of deionized water containing 4.925 g 2-methylimidazole was quickly mixed with the above solution and stirred for five minutes. The cleaned nickel foam was cut into fragments about 2.4 × 4 cm and then soaked in the mixed solution for 24 hours.…”

Flexible and Alternately Layered High‐Loading Film Electrode based on 3D Carbon Nanocoils and PEDOT:PSS for High‐Energy‐Density Supercapacitor

“…[ 16 ] As the material mass loading increases, the electrochemical properties of the electrode would be improved, but the flexibility would be degraded. [ 17 ] In this regard, how to improve the mass loading of electrode without compromising the flexibility and other electrochemical properties is still of challenge.…”