Non‐Thermal Plasma Assisted Fabrication of Ultrathin NiCoO_x Nanosheets for High‐Performance Supercapacitor

Abstract

Transition metal based layered double hydroxides (TMLDHs) are potential candidates for supercapacitors; however, their structural staking often limits their energy density, one of the major pending obstacles in the sector. Simple, fast, and safe modification strategies such as exfoliation of jammed layers into single sheets can be a viable option to overcome those challenges. This work reports fabrication of an ultrathin nanosheets from bulk TMLDHs using superficial non-thermal Arplasma exfoliation strategy. Electrochemical characterizations have confirmed that capacitive performance of pristine NiCoO x nanosheets has improved because of Ar-plasma induced exfoliation. A remarkable of 5.7 F cm À 2 areal capacitance was achieved at a current density of 5 mA cm À 2 for ultrathin Ar-NiCoO x nanosheets. The material also exhibited excellent cyclic stability with over 88 % capacitance retention after 5000 cycles. The electrode material assembled into symmetric supercapacitor device delivering an energy density of 85.9 μWh cm À 2 at a power density of 500 μW cm À 2 .The higher supercapacitive performance is attributed to increased electrochemical surface area and improved capability of electron and ion transport induced by Ar-plasma exfoliation, demonstrating an opportunity for further use of TMLDHs in the energy conversion and storage sector.

Oxygen Vacancy Generation and Stabilization in Layered NiFeCo Double Hydroxide Nanosheets for a Highly Efficient Oxygen Evolution Reaction

“…37 To enhance the catalytic activity of b-NiFeCo LDHs, it is imperative to undertake the exfoliation of the sizable lateral dimensions and thickness of the bulk material, thereby yielding stable monolayer nanosheets characterized by an increased availability of exposed active sites. 38 In pursuit of this objective, b-NiFeCo LDH was subjected to high-energy Ar-plasma treatment to accomplish the exfoliation of the bulk LDH into ultrathin nanosheets while simultaneously introducing oxygen vacancies (Vo). Subsequent to a 30 min Ar-plasma exfoliation process (herein referred to as Vo-NiFeCo LDHs), thinner, aslant laying, and open network nanosheet morphologies are formed, as depicted in Figure 1e.…”

“…For bulk NiFeCo LDHs (denoted as b-NiFeCo LDHs), uniformly grown and interconnected nanosheet arrays are vertically aligned on nickel foam (NF), forming a wall-like structure (Figure b), i.e., a typical morphology for LDHs . To enhance the catalytic activity of b-NiFeCo LDHs, it is imperative to undertake the exfoliation of the sizable lateral dimensions and thickness of the bulk material, thereby yielding stable monolayer nanosheets characterized by an increased availability of exposed active sites . In pursuit of this objective, b-NiFeCo LDH was subjected to high-energy Ar-plasma treatment to accomplish the exfoliation of the bulk LDH into ultrathin nanosheets while simultaneously introducing oxygen vacancies (Vo).…”

Ni-based ultrathin nanostructures for overall electrochemical water splitting

“…78 Their unique qualities are derived from their ultrathin thickness, and these appealing properties lead to more exposed active sites and enhanced mass or ion movement, which are useful for improving the electrocatalytic performance. 39 Many synthesis methods of the Ni-utNSs have been reported, and they mainly include the solvothermal (hydrothermal) method, 79,80 coprecipitation method, 81 electrochemical deposition method, 82 and sol-gel methods. 83 To further understand the influence of the synthesis methods on the structure and composition of the Ni-utNSs, we introduce some common synthesis methods and exfoliation methods in detail in the following part.…”

Advances in All-Solid-State Lithium–Sulfur Batteries for Commercialization

“…Amidst the established strategies, a transition away from fossil fuels to low-carbon solutions is imperative for industries with high carbon emissions, specifically the transportation industry [3][4][5]. To enable this transition, it is crucial to develop technological advancements in the form of energy storage and conversion systems that can effectively store surplus renewable energy during periods of low consumption and supply it during periods of high consumption [6,7].…”