Preparation of a NbN/graphene nanocomposite by solution impregnation and its application in high-performance Li-ion hybrid capacitors

Abstract

Lithium-ion hybrid capacitors (LIHCs) have received a mushrooming amount of attention due to their high power density and energy density. However, the imbalanced dynamics between positive and negative electrodes limit their practical applications. Thus, in order to develop a kind of anode material with high power, we report a simple synthesis technology of a NbN nanoparticles/graphene nanosheets (NbN/ GNSs) nanocomposite with fast Li insertion/extraction properties. Through a facile solution impregnation followed by annealing treatment, we get a freestanding layer-stacked structure combining 2D graphene nanosheets and 0D NbN nanoparticles. It shows a high reversible capacity of z 450 mA h g À1 at 0.1 A g À1 , moreover, as a result of the fast pseudocapacitive performance, it also shows a remarkable rate capability and cycle stability (90% capacity retention at 5 A g À1 after 10 000 cycles). Meanwhile, the LIHC with a NbN/GNSs anode and activated polyaniline derived carbon (APDC) cathode delivers the maximum energy density of 136 W h kg À1, and the highest power density of 25 kW kg À1 as well as a stable cycle life in the potential range of 1.0-4.0 V.

Supercapatteries as High-Performance Electrochemical Energy Storage Devices

“…To address this, various hybrid EES devices have been proposed and preliminarily demonstrated in which such hybrid devices can combine the merits of supercapacitors with those of rechargeable batteries into one device. However, a unified generic term was lacking for these devices and researchers have generally referred to them using different nomenclatures such as 'redox capacitors' [2,3], 'Li-ion capacitors' [4][5][6][7][8], 'Naion capacitors' [8][9][10], 'hybrid electrochemical capacitors' [11][12][13][14], battery-supercapacitor hybrids [15] or 'pseudocapacitors' [16][17][18] corresponding to electrode material and device design and engineering. As a result, a generic term 'supercapattery' (= supercapacitor + battery) was proposed to represent these EES hybrid devices that are different from either supercapacitors or rechargeable batteries in terms of fundamental principles and technological prospects.…”

Tunable Synthesis of 3D Niobium Oxynitride Nanosheets for Lithium-Ion Hybrid Capacitors with High Energy/Power Density

“…The reduction peak at around 0.68 V in the initial cycle disappeared in subsequent cycles, indicating the formation of an SEI film. 49 The CV curves of the second and later cycles are completely coincident, demonstrating that the NbON-1.5 h electrode exhibits excellent reversibility for Li + insertion/extraction. Meanwhile, there are several broad cathodic peaks at 2.07, 1.38, and 0.01 V and anodic peaks at 0.16, 1.22, and 1.88 V in the discharging/charging curves.…”

“…The first five continuous CV cycles at a scan rate of 0.1 mV s –1 were performed to analyze lithium-ion insertion/extraction reactions to/from NbON-1.5 h, as shown Figure a. The reduction peak at around 0.68 V in the initial cycle disappeared in subsequent cycles, indicating the formation of an SEI film . The CV curves of the second and later cycles are completely coincident, demonstrating that the NbON-1.5 h electrode exhibits excellent reversibility for Li + insertion/extraction.…”

“…Meanwhile, there are several broad cathodic peaks at 2.07, 1.38, and 0.01 V and anodic peaks at 0.16, 1.22, and 1.88 V in the discharging/charging curves. The presence of multi-peaks indicates a complicated electrochemical behavior in the discharging/charging process, which can be described using the following equation derived from previous reports , where z is the number of lithium ions inserted into NbO x N y and its value is from 0.01 to 5. To better understand the kinetics, CV profiles of NbON-1.5 h at various scan rates (Figure b,c) were measured.…”

Performance and future directions of transition metal sulfide‐based electrode materials towards supercapacitor/supercapattery

“…Recently, a new terminology supercapattery has gained ample attention in terms of their power and energy dissipation by combining the synergistic effect of both battery-type non-capacitive faradic mechanisms along with supercapacitor electrodes following capacitive non-faradic/faradic mechanisms (Guan et al, 2016;Xia et al, 2017). Supercapattery is considered to be a more cohesive generic term proposed to represent different nomenclatures anticipated such as battery-supercapacitor hybrid capacitors (Zuo et al, 2017), lithium, sodium ion-based capacitors (Chen et al, 2017;Wang, Zhu, et al, 2017), hybrid, and so on (Cherusseri et al, 2019;Rafai et al, 2019). Several lately reported studies to point toward competent electrode development and material design for real field applicability and classify them accordingly.…”