Research progress and future aspects: Metal selenides as effective electrodes

MXene in core–shell structures: research progress and future prospects

“…17,18 Scientic studies of electrode materials such as carbon nanotubes, graphene oxide (GO), metal chalcogenides, metalorganic frameworks (MOFs), metal phosphides, high-entropy alloys, and layered hydroxides, and their progress in transiting towards hybrid materials and oriented structures have been signicant and well investigated throughout the years. [19][20][21][22][23][24][25][26][27] For example, transition metal oxides, [28][29][30][31][32] suldes, [33][34][35][36] porous carbon, 37 GO, 38 and reduced GO (rGO) are well-known 2D materials which have been utilized and evaluated in various applications. [39][40][41] 2D structures are desirable as they can act as protective shells or coatings, and also act as substrates to further grow nanomaterials.…”

Phase-Dependent Energy Storage Performance of the NixSey Polymorphs for Supercapacitor-Battery Hybrid Devices

“…Transition-metal chalcogenides (most often, metal sulfides/selenides/tellurides), notably in the form of nanostructures, have been a hot topic of study in recent years due to their unique multiple oxidation states, reversible Faradaic reactions, and high theoretical specific capacities. − For the elements of the oxygen family, the metallic characteristic increases whereas electronegativity and ionization energy decrease while progressing down the group. , Thus, although transition-metal selenides (TMSe) have physicochemical properties similar to those of metal oxides and sulfides, they exhibit better metallic properties (e.g., a higher electrical conductivity) and so can be used in advanced energy storage devices. The high electrical conductivity of TMSe results from the covalent character of the metal–selenium connections, which is substantially different from the ionic nature of the metal–oxygen bonds in metal oxides. , This property stems from the selenium ions that have d-orbitals of accessible energy, whereas oxygen and sulfur anions do not, and this leads to wide valence bands and, hence, narrower band gaps compared to those of the corresponding oxides/sulfides .…”

Plant- and fungi-inspired hierarchical structures as electrode materials: a review

“…1–14 Due to their extended cycle life, high power density, and Coulombic efficiency, as well as low maintenance requirements, supercapacitors (SCs) are being hailed as promising energy storage systems. 15–21 Higher demands are put on today′s state-of-the-art supercapacitors in the areas of electrochemical performance, fabrication cost, sustainability, environmental friendliness, and intelligent application because they are being seen as a dominant energy-storage technology to sustainably power various portable electronics and large electric vehicles in our modern society. 1,22–26 SC electrode materials are categorized as electrical double layer capacitive- (EDLC), battery-, and pseudocapacitive-type based on the mechanism of energy storage.…”