Highly stable binary composite of nickel silver sulfide ( NiAg ₂ S ) synthesized using the hydrothermal approach for high‐performance supercapattery applications

Abstract

Summary A supercapattery is a device that combines the benefits of supercapacitors' superior power density and cycle stability with the advantages of batteries' higher energy density. We used a simple hydrothermal method to synthesize nickel sulfide (NiS), silver sulfide (Ag2S), and nickel silver sulfide (NiAg2S). The NiS and Ag2S were combined in the best 50/50 weight ratio and found that the specific capacity for NiAg2S is 571.2 C/g which is higher as compared to individual NiS and Ag2S 305.2 C/g and 364 C/g, respectively. Even at 2 A/g, more than 69% of the specific capacity is retained. For asymmetric device fabrication (NiAg2S//AC), the activated carbon was selected as a negative electrode, while NiAg2S was chosen as a positive electrode. A specific capacity of 130.4 C/g was achieved with this device. Energy density for NiAg2S was observed to be 28.97 Wh/kg having a power density of 640 W/kg. To investigate stability, a durability test was performed by subjecting this device to 1000 charging/discharging cycles, which maintain 86% of the initial capacity. Our findings suggest that a mixture of nickel and silver sulfide having a 50/50 weight ratio functioning as an electrode material for supercapattery applications may be more appropriate.

Enhanced the electrochemical performance and stability of supercapattery device with carbon nanotube/cobalt‐manganese sulfide‐based composite electrode material

“…For supercapattery, the b-values exists between 0.5 and 0.8. 55 As can be observed in Figure 6A, the computed b-values are within the supercapattery range. As a result, both faradic processes, as well as charge adsorption/desorption, are responsible for the charge stored throughout this device.…”

“…The nature of the electrode is supercapacitor, if the b ‐value is 0.8 to 1.0. For supercapattery, the b ‐values exists between 0.5 and 0.8 55 . As can be observed in Figure 6A, the computed b ‐values are within the supercapattery range.…”

MnNbS/Polyaniline Composite‐Based Electrode Material for High‐Performance Energy Storage Hybrid Supercapacitor Device

“…Supercapattery has b‐values ranging from 0.5 to 0.8. [ 46 ] As shown in Figure 6a, the calculated b‐values fall inside the supercapattery zone. As an outcome, the charge retained through this device is due to both Faradic reactions and diffusion control processes.…”

A bimetallic Fe–Mg MOF with a dual role as an electrode in asymmetric supercapacitors and an efficient electrocatalyst for hydrogen evolution reaction (HER)

“…Supercapacitors (SCs) have emerged as an up-and-coming alternative owing to their exceptional qualities, encompassing high power density, extended lifespan, and rapid charging capabilities. [1][2][3][4] These advantageous characteristics make them an attractive choice for various applications in energy storage. Still, supercapacitors' relatively low energy density presents a hurdle to their extensive utilization in areas that simultaneously full high energy and power requirements.…”