Hydrothermal Growth of MnO2 at 95 oC as an Anode Material

The hydrothermal growth of manganese dioxide was carried out on indium tin dioxide coated glass substrates using potassium permanganate at 95 oC for 24 h and adjusting the pH solution to 3 and 4 through nitric acid. The best capacitive response was observed from the hexagonal ε-manganese dioxide at pH 4 having a specific charge of 129 ± 1 A g-1 and specific discharge capacity of 943 mAh g-1 with capacitance retention of 98 % after 500 scans at 4 A g-1 presenting high rate performance and good stability. The importance of achieving crystalline electrodes with high specific surface area towards the improvement of their capacitive performance for power devices is highlighted

V2O5 as magnesium cathode material with extended cyclic stability

In this work, the electrochemical performance of aerosol-assisted chemical vapour deposited vanadium pentoxide cathodes at 600 °C, is presented. The as-grown oxides indicate specific discharge capacity of 300 mA h g-1 with capacity retention of 92 % after 10000 scans, coulombic efficiency of 100 %, noble structural stability and high reversibility. The present study shows the possibility to grow large-area magnesium cathode material with extended cycle stability via utilization of an aqueous electrolyte under a corrosive environment. This enhanced performance may be a combination of electrode morphology and adherence, when compared to previous work employing electrode growth temperature at 500 °C

Towards High Performance Chemical Vapour Deposition V2O5 Cathodes for Batteries Employing Aqueous Media

The need for clean and efficient energy storage has become the center of attention due to the eminent global energy crisis and growing ecological concerns. A key component in this effort is the ultra-high performance battery, which will play a major role in the energy industry. To meet the demands in portable electronic devices, electric vehicles, and large-scale energy storage systems, it is necessary to prepare advanced batteries with high safety, fast charge ratios, and discharge capabilities at a low cost. Cathode materials play a significant role in determining the performance of batteries. Among the possible electrode materials is vanadium pentoxide, which will be discussed in this review, due to its low cost and high theoretical capacity. Additionally, aqueous electrolytes, which are environmentally safe, provide an alternative approach compared to organic media for safe, cost-effective, and scalable energy storage. In this review, we will reveal the industrial potential of competitive methods to grow cathodes with excellent stability and enhanced electrochemical performance in aqueous media and lay the foundation for the large-scale production of electrode materials

Aerosol-assisted chemical vapor deposition of V2O5 cathodes with high rate capabilities for magnesium-ion batteries

The growth of orthorhombic vanadium pentoxide nanostructures was accomplished using an aerosol-assisted chemical vapor deposition process. These materials showed excellent electrochemical performance for magnesium-ion storage in an aqueous electrolyte; showing specific discharge capacities of up to 427 mAh g−1 with a capacity retention of 82% after 2000 scans under a high specific current of 5.9 A g−1. The high rate capability suggested good structural stability and high reversibility. We believe the development of low-cost and large-area coating methods, such as the technique used herein, will be essential for the upscalable fabrication of next-generation rechargeable battery technologies

A new standard method to calculate electrochromic switching time

The switching time is one of the key parameters used to assess the performance of an electrochromic material or device. In spite of its importance, there is currently no standard for how this parameter is defined, and as a result, it is difficult to compare switching time data between different research groups, and to quantify and assess reported improvements. We propose a standard method for reporting electrochromic switching times, based on straightforward experimental fittings resulting in an analytical expression that can directly correlate obtainable optical contrast values with their corresponding switching times. This analytical expression makes it possible to unambiguously define the performance of an electrochromic material or device using two parameters: a full-switch contrast and a time constant