Chitosan and Phthaloylated Chitosan in Electrochemical Devices

Chitin and chitosan are widely found in nature. Chitin can be obtained from fungi and in the lower animals. Chitosan can be derived from chitin. The process of chitosan derivation from chitin is called deacetylation. Chitosan is non-toxic, odourless, biocompatible in animal tissues and enzymatically biodegradable. It has found many applications in the fields of cosmetics, wound healing, dietetics and waste-water treatment. Chitosan holds many promising potentials, but its inability to dissolve in many of the common solvents has restricted its application. Hence, chitosan has been modified, and there are now many derivatives of chitosan. In the current chapter, we discuss chitosan and only the phthaloyl chitosan derivative. Their applications in several electrochemical devices are also discussed

Annealing effect on structural and electrochemical performance of Ti-doped LiNi1/3Mn1/3Co1/3O2 cathode materials

NMC 111 cathode materials exhibit engaging properties in high energy density and low cost, making it great potential for the next generation of high-energy lithium-ion batteries. However, it still faces challenges such as fast capacity fade, especially at high C rates. Herein, we implement the novel Ti-doped cathode material, LiNi0.3Mn0.3Co0.3Ti0.1O2 (NMCT) synthesized via the combustion method. It was discovered that NMCT can effectively improve capacity delivery at high C rates. The T80 material demonstrated superior electrochemical annealed at 800 ˚C for 72 h, with an exceptional specific discharge capacity of 148.6 mAh g-1 and excellent cycle stability (capacity retention 96.8 %) after 30th cycles at 3 C. The results demonstrated that Ti-doped NMC had superior advantages for LiNi1/3Mn1/3Co1/3O2 (NMC 111) material at the optimum temperature of 800 °C for 72 h. It is one of the potential cathode materials for Li-ion batteries

Impacts of Denial-of-Service Attack on Energy Efficiency Pulse Coupled Oscillator

The Pulse Coupled Oscillator (PCO) has attracted substantial attention and widely used in wireless sensor networks (WSNs), where it utilizes firefly synchronization to attract mating partners, similar to artificial occurrences that mimic natural phenomena. However, the PCO model might not be applicable for simultaneous transmission and data reception because of energy constraints. Thus, an energy-efficient pulse coupled oscillator (EEPCO) has been proposed, which employs the self-organizing method by combining biologically and non-biologically inspired network systems and has proven to reduce the transmission delay and energy consumption of sensor nodes. However, the EEPCO method has only been experimented in attack-free networks without considering the security elements which may cause malfunctioning and cyber-attacks. This study extended the experiments by testing the method in the presence of denial-of-service (DoS) attacks to investigate the efficiency of EEPCO in attack-based networks. The result shows EEPCO has poor performance in the presence of DoS attacks in terms of data gathering and energy efficiency, which then concludes that the EEPCO is vulnerable in attack-based networks

Studies on the properties of silicone resin blend materials for corrosion protection

Purpose - Corrosion protection is one of the important performance properties of organic coatings. The purpose of this paper is to develop a paint system for the protection of steel substrates from corrosion at high temperature atmospheres using silicone resin blend materials. Design/methodology/approach - An anti-corrosion paint system for high temperature atmosphere has been developed using silicone polyester resins. Silicone resin has been chosen due to its good resistance for corrosion in all kinds of environments. The paint system was prepared from the best performing binder system with the addition of inorganic pigments. Heat stability was studied according to ASTM D2485 standards. Adhesion, impact resistance, film formation, thermal stability and electrochemical properties of the prepared coatings were evaluated by cross hatch adhesion method, tubular impact testing, scanning electron microscopy, differential scanning calorimetry (DSC), and electrochemical impedance spectroscopy (ELS), respectively. Findings - The paint system possessed good adhesion properties and had high-impact resistance. The SEM graphs showed the uniform formation of the film surface. From thermal analyses, the prepared paint system withstood temperatures up to 400 degrees C. The heat-treated specimen has also been evaluated for corrosion protection by EIS, which showed high resistance after 30 days of immersion in 3 percent NaCl solution. Originality/value - In this work, an attempt has been made to develop a good paint system using silicone resin and polyester resin blend materials. This research will be useful for the application for high temperature atmosphere and it can give a valuable guidance to the students who are interested in pursuing research in organic coatings

Synthesis and characterization of Ti-doped MgMn2O4 cathode material for magnesium ion batteries

Magnesium batteries demonstrate potential candidate for next-generation energy storage devices because of their high energy density and low raw-materials costs. In comparison with lithium, magnesium is inherently much safer due to its air stable and environmental friendly. In the present work, magnesium manganese oxide (MgMn 2 O 4 ) with Ti-doped was synthesized by a self-propagating combustion method using citric acid as a reducing agent. The precursors of MgMn 2 O 4 and MgMn (2-x) Ti x O 4 , (x = 0.1) were annealed at 700 °C for 24 h. The prepared samples were further characterized by using Simultaneous Thermal Analysis (STA), X-ray diffraction (XRD), and Field Emission Scanning Electron Microscopy (FESEM). Then, the optimized sample was used as cathode in magnesium ion battery using polymer-based electrolyte. The charge-discharge profile of the fabricated battery was discussed

Silver Nanoparticles Embedded on Reduced Graphene Oxide@Copper Oxide Nanocomposite for High Performance Supercapacitor Applications

In this work, silver (Ag) decorated reduced graphene oxide (rGO) coated with ultrafine CuO nanosheets (Ag-rGO@CuO) was prepared by the combination of a microwave-assisted hydrothermal route and a chemical methodology. The prepared Ag-rGO@CuO was characterized for its morphological features by field emission scanning electron microscopy and transmission electron microscopy while the structural characterization was performed by X-ray diffraction and Raman spectroscopy. Energy-dispersive X-ray analysis was undertaken to confirm the elemental composition. The electrochemical performance of prepared samples was studied by cyclic voltammetry and galvanostatic charge-discharge in a 2M KOH electrolyte solution. The CuO nanosheets provided excellent electrical conductivity and the rGO sheets provided a large surface area with good mesoporosity that increases electron and ion mobility during the redox process. Furthermore, the highly conductive Ag nanoparticles upon the rGO@CuO surface further enhanced electrochemical performance by providing extra channels for charge conduction. The ternary Ag-rGO@CuO nanocomposite shows a very high specific capacitance of 612.5 to 210 Fg−1 compared against rGO@CuO which has a specific capacitance of 375 to 87.5 Fg−1 and the CuO nanosheets with a specific capacitance of 113.75 to 87.5 Fg−1 at current densities 0.5 and 7 Ag−1, respectively

Silver Nanoparticle Decorated on Reduced Graphene Oxide-Wrapped Manganese Oxide Nanorods as Electrode Materials for High-Performance Electrochemical Devices

In this work, silver nanoparticles decorated on reduced graphene oxide (rGO) wrapped manganese oxide nanorods (Ag-rGO@MnO2) were synthesized for an active electrode material. MnO2 nanorods were synthesized via a hydrothermal route, and their coating with GO and subsequent reduction at a higher temperature resulted in rGO@MnO2. A further addition of Ag on rGO@MnO2 was performed by dispersing rGO@MnO2 in AgNO3 solution and its subsequent reduction by NaBH4. X-ray diffraction (XRD) analysis showed peaks corresponding to MnO2 and Ag, and the absence of a peak at 2θ = 26° confirmed a few layered coatings of rGO and the absence of any graphitic impurities. Morphological analysis showed Ag nanoparticles anchored on rGO coated MnO2 nanorods. Apart from this, all other characterization techniques also confirmed the successful fabrication of Ag-rGO@MnO2. The electrochemical performance examined by cyclic voltammetry and the galvanic charge–discharge technique showed that Ag-rGO@MnO2 has a superior capacitive value (675 Fg−1) as compared to the specific capacitance value of rGO@MnO2 (306.25 Fg−1) and MnO2 (293.75 Fg−1). Furthermore, the electrode based on Ag-rGO@MnO2 nanocomposite showed an excellent capacity retention of 95% after 3000 cycles. The above results showed that Ag-rGO@MnO2 nanocomposites can be considered an active electrode material for future applications in electrochemical devices

Silver Nanoparticle Decorated on Reduced Graphene Oxide-Wrapped Manganese Oxide Nanorods as Electrode Materials for High-Performance Electrochemical Devices

In this work, silver nanoparticles decorated on reduced graphene oxide (rGO) wrapped manganese oxide nanorods (Ag-rGO@MnO2) were synthesized for an active electrode material. MnO2 nanorods were synthesized via a hydrothermal route, and their coating with GO and subsequent reduction at a higher temperature resulted in rGO@MnO2. A further addition of Ag on rGO@MnO2 was performed by dispersing rGO@MnO2 in AgNO3 solution and its subsequent reduction by NaBH4. X-ray diffraction (XRD) analysis showed peaks corresponding to MnO2 and Ag, and the absence of a peak at 2θ = 26° confirmed a few layered coatings of rGO and the absence of any graphitic impurities. Morphological analysis showed Ag nanoparticles anchored on rGO coated MnO2 nanorods. Apart from this, all other characterization techniques also confirmed the successful fabrication of Ag-rGO@MnO2. The electrochemical performance examined by cyclic voltammetry and the galvanic charge–discharge technique showed that Ag-rGO@MnO2 has a superior capacitive value (675 Fg−1) as compared to the specific capacitance value of rGO@MnO2 (306.25 Fg−1) and MnO2 (293.75 Fg−1). Furthermore, the electrode based on Ag-rGO@MnO2 nanocomposite showed an excellent capacity retention of 95% after 3000 cycles. The above results showed that Ag-rGO@MnO2 nanocomposites can be considered an active electrode material for future applications in electrochemical devices

Li2SnO3 Anode Synthesized via Simplified Hydrothermal Route Using Eco-Compatible Chemicals for Lithium-Ion Battery

Low cost group IV element (Sn) based-materials can provide high capacity substitute for lithium-ion batteries (LIBs). Tin based oxide Li2SnO3 was successfully synthesized via low temperature hydrothermal route without further calcination and used as anode materials in LIBs. In this work, eco-compatible chemicals Tin (IV) oxide, SnO2 and lithium hydroxide monohydrate, LiOH.H2O were used as starting reagents. XRD results show that the monoclinic crystal structure Li2SnO3 is of high purity. This finding agrees with TEM micrographs that display nano-sized particle with interplanar spacing corresponding to (110) and (101) lattice planes. The narrow particle size distribution of 50-60 nm predicts the outstanding performance of LIBs. The first cycle discharge capacity is 2582 mAhg-1. However, the cycling performance only maintain in between 180-290 mAhg-1 up to 50 cycles. The mechanism of Li reactivity in Li2SnO3 is through Li-Sn alloying/de-alloying process. The diffusion coefficient of Li+ ion is calculated as 2.144 × 10-13 cm2 s-1. Impedance studies of LIB cells proof the formation of SEI at the first cycle and explains the poor stability of the cells