Pseudocapacitive nanostructured silver selenide thin film through room temperature chemical route: First approach towards supercapacitive application

Hierarchical Mn3O4/NiSe2-MnSe2: A Versatile Electrode Material for High-Performance All-Solid-State Hybrid Pseudocapacitors with Supreme Working Durability

As highly efficient electrochemical energy storage devices are in indispensable demand for numerous modern-day technologies, herein sluggish precipitation followed by an anion exchange procedure has been developed to synthesize an oxide-selenide mixed phase (Mn3O4/NiSe2-MnSe2) novel electrode material with high surface area and porosity for high-performance all-solid-state hybrid pseudocapacitors (ASSHPC). Mn3O4/NiSe2-MnSe2 shows a rich Tyndall effect (in H2O) and possesses randomly arranged low-dimensional crystallites of nearly similar size and uniform shape. The electrochemical analyses of Mn3O4/NiSe2-MnSe2 corroborate good electrochemical reversibility during charge transfer, superior pseudocapacitive charge-storage efficiency, and very low charge transfer and series resistance, ion-diffusion resistance, and relaxation time, which endorse the quick pseudocapacitive response of the material. The Mn3O4/NiSe2-MnSe2||N-rGO ASSHPC device demonstrates excellent charge-storage physiognomies suggestive of rich electrochemical and electromicrostructural compatibility between the electrode materials in the fabricated assembly. The Mn3O4/NiSe2-MnSe2||N-rGO ASSHPC device delivers high mass and area specific capacitance/capacity, very low charge-transfer resistance (∼0.74 Ω), total series resistance (∼0.76 Ω), diffusion resistance, and a relaxation time constant, which endorse the quick pseudocapacitive response of the device. The device delivers higher energy and power density (∼34 W h kg-1 at ∼2994 W kg-1), rate efficiency (∼17 W h kg-1 at ∼11,995 W kg-1), and cyclic performance (∼97.2% specific capacity/capacitance retention after 9500 continuous GCD cycles). The superior Ragone and cyclic efficiencies of the ASSHPC device are ascribed to the multiple redox-active Ni and Mn ions which lead to the supplemented number of redox reactions; "electroactive-ion buffering pool"-like physiognomics of Mn3O4/NiSe2-MnSe2, which facilitate the electrolyte ion dissemination to the electroactive sites even at high rate redox condition; and ideal electro-microstructural compatibility between the electrode materials, which leads to assisted charge transfer and absolute ion dissemination during the charge-storage process.

Recent Advancements in Chalcogenides for Electrochemical Energy Storage Applications

Energy storage has become increasingly important as a study area in recent decades. A growing number of academics are focusing their attention on developing and researching innovative materials for use in energy storage systems to promote sustainable development goals. This is due to the finite supply of traditional energy sources, such as oil, coal, and natural gas, and escalating regional tensions. Because of these issues, sustainable renewable energy sources have been touted as an alternative to nonrenewable fuels. Deployment of renewable energy sources requires efficient and reliable energy storage devices due to their intermittent nature. High-performance electrochemical energy storage technologies with high power and energy densities are heralded to be the next-generation storage devices. Transition metal chalcogenides (TMCs) have sparked interest among electrode materials because of their intriguing electrochemical properties. Researchers have revealed a variety of modifications to improve their electrochemical performance in energy storage. However, a stronger link between the type of change and the resulting electrochemical performance is still desired. This review examines the synthesis of chalcogenides for electrochemical energy storage devices, their limitations, and the importance of the modification method, followed by a detailed discussion of several modification procedures and how they have helped to improve their electrochemical performance. We also discussed chalcogenides and their composites in batteries and supercapacitors applications. Furthermore, this review discusses the subject’s current challenges as well as potential future opportunities.