All-Solid-State Supercapacitor Based on Advanced 2D Vanadium Disulfide/Black Phosphorus Hybrids for Wearable Electronics

Abstract

Vanadium disulfide−black phosphorus (VS 2 −BP) hybrids were synthesized by a one-pot hydrothermal-assisted method to achieve enhanced electrochemical activity for supercapacitor applications. The concentration of BP was optimized to prevent the restacking nature of VS 2 and to enrich the active edges for electrolytic ion intercalation. The charge storage kinetics of the best-performing VS 2 −BP as an active electrode has demonstrated the dominance of the pseudocapacitive nature of the material. Furthermore, by sandwiching with a PVA/K 2 SO 4 gel electrolyte, an all-solid-state (ASS) vanadium disulfide−black phosphorus-50 mg (VS 2 −BP-50) symmetric device was developed on highly conductive carbon paper. The ASS VS 2 −BP-50 symmetric device displays the highest specific areal capacitance of 203.25 mF/cm 2 and exhibits the maximum areal energy density of 28.22 μW h cm −2 at an areal power density of 596.09 mW cm −2 , outperforming the previous literature. To understand the origin of the high quantum capacitance, we used density functional theory (DFT) and found that the charge accumulation region between VS 2 and BP monolayers and the charge transfer are the origin of the improved density of states in the VS 2 −BP hybrid. Moreover, exceptional mobility of K + ions and a higher diffusion rate were observed using the DFT method.

Hierarchal Growth of Integrated n-MoS2/p-Black Phosphorus Heterostructures for All-Solid-State Asymmetric Supercapacitor Electrodes

“…The resulting solution was diluted to 60 mL, placed in a Teflon-lined autoclave, and heated to 200 °C in a hot-air oven for 24 h. After being washed with distilled water and ethanol, the black product was dried overnight in a vacuum oven at 60 °C. 22 2.2. Material Characterization.…”

“…For the first time, Hao et al developed a flexible supercapacitor out of exfoliated BP. 21 Previously, our group demonstrated that forming heterostructures with BP improves the performance of pseudocapacitive 2D materials like VS 2 22 and conducting polymers such as PANI. 23 To exemplify, the addition of BP to VS 2 increased the number of electrochemical active sites, resulting in enhanced surface activity.…”

“…Thus, it can be conveniently applied as the cathode material in the fabrication of ASC, which resulted in magnified performance. 22 Further, considering the significance of BP and MoS 2 , Reddy et al synthesized the MoS 2 /BP photocatalyst by the hydrothermal method, 24 while Liang et al 25 and He et al 26 investigated the HER activity of MoS 2 /BP. In their study, they discovered that MoS 2 /BP heterostructure with numerous active sites and effective interfaces exhibited significant HER catalytic performance.…”

Perspective of Vanadium Disulfide: A Rising Star Finds Plenty of Room in Single and Multielectron Energy Storage

“…The presence of BP can expand the number of active sites and increase the surface activity while avoiding stacking. 196 A charming cocktail effect produced by composite materials has attracted more interests to obtain satisfactory properties in different fields. By compounding with active materials to achieve a stable structure, the problem of volume expansion can be effectively reduced, and the synergistic effect between various materials can effectively increase the diffusion rate of ions.…”

“…Sharma et al combined VS 2 with black phosphorus (BP) to form composite VS 2 /BP, which showed good electrochemical performance for supercapacitors. The presence of BP can expand the number of active sites and increase the surface activity while avoiding stacking …”