Facile synthesis and simulation of MnO2 nanoflakes on vertically aligned carbon nanotubes, as a high-performance electrode for Li-ion battery and supercapacitor

Overview of recent developments in carbon-based nanocomposites for supercapacitor applications

Energy storage devices are recognized as environmentally friendly technologies. Supercapacitors, known for their high cycle stability, have been proposed as potential alternatives to fossil fuels. Recent studies have focused on selecting suitable electrode materials to achieve energy storage systems with high stability, high specific capacity, and biocompatibility. In particular, carbon-based electrode materials, such as graphene oxide, activated carbon, carbon nanotubes, and carbon-based quantum dots, have attracted considerable attention due to their intrinsic properties, such as high conductivity and stability. However, carbon materials alone exhibit limitations, such as low energy density and low specific capacitance. To address this limitation, the synergistic effect of carbon materials has been combined with other electroactive materials to develop electrode materials with enhanced supercapacitor properties. The present study also investigates the supercapacitor performance of carbon-based nanocomposites. It examines the effect of each carbon material (AC, CNT, GO, rGO) on improving the performance of other electroactive materials, including metal oxides, metal sulfides, MXenes, MOFs, and conductive polymers. This study provides valuable insights for further studies on carbon-based electrode materials for supercapacitor applications.

Overview of the oxygen vacancy effect in bimetallic spinel and perovskite oxide electrode materials for high-performance supercapacitors

Bimetallic spinel and perovskite metal oxide materials are advanced electrode materials for supercapacitor (SC) applications because of their low-cost, distinct crystal structures, eco-friendly nature, and high conductivity. However, they suffer from the disadvantages of poor ion-diffusion kinetics and pulverization issues during cyclability tests. Along with a deeper understanding of redox chemistry, the role of oxygen vacancies (OVs) in electrode materials to support the reaction kinetics for excellence in SCs must be clarified. In this review, we highlight for the first time the importance of OVs and summarize various design strategies for the preparation of advanced bimetallic spinel oxides and perovskites with improved electrochemical performances for SC applications. With new insights, we envision that the SC research community would endeavor to utilize the benefits of OVs effectively for the development of high-performance SCs.

Nano and Battery Anode: A Review

Improving the anode properties, including increasing its capacity, is one of the basic necessities to improve battery performance. In this paper, high-capacity anodes with alloy performance are introduced, then the problem of fragmentation of these anodes and its effect during the cyclic life is stated. Then, the effect of reducing the size to the nanoscale in solving the problem of fragmentation and improving the properties is discussed, and finally the various forms of nanomaterials are examined. In this paper, electrode reduction in the anode, which is a nanoscale phenomenon, is described. The negative effects of this phenomenon on alloy anodes are expressed and how to eliminate these negative effects by preparing suitable nanostructures will be discussed. Also, the anodes of the titanium oxide family are introduced and the effects of Nano on the performance improvement of these anodes are expressed, and finally, the quasi-capacitive behavior, which is specific to Nano, will be introduced. Finally, the third type of anodes, exchange anodes, is introduced and their function is expressed. The effect of Nano on the reversibility of these anodes is mentioned. The advantages of nanotechnology for these electrodes are described. In this paper, it is found that nanotechnology, in addition to the common effects such as reducing the penetration distance and modulating the stress, also creates other interesting effects in this type of anode, such as capacitive quasi-capacitance, changing storage mechanism and lower volume change.