Nanoscience & Nanotechnology-Asia - Volume 5, Issue 2, 2015

Driven by the great need for improved energy storage solutions, several research groups have investigated a variety of materials with the goal of developing the next generation of electrochemical energy storage device. In this review, we focus on candidate materials for the development of high energy density anodes. We critically summarize the most recent advances in the use of silicon, tin, and few metal oxides as electrode materials in lithium ion batteries. Because of its abundance and its high specific capacity, silicon is the most attractive candidate material, despite presenting great challenges with respect to its structural stability and transport properties. After several year of intense investigation, which resulted in a huge range of nanostructures being tested and characterized, we can now identify few important contributions that confirm that it is possible to successfully integrate silicon in anode that achieves satisfactory charge/discharge cycle lifetime. Additional work is needed to demonstrate device stability in active layers with density and weight loading comparable to those of real-life devices. In addition, further investigations need to focus on the processing science of siliconcontaining nanostructured materials, with the goal of developing a route that is competitive with the production volume of current anode materials.

This review article discusses about various aspects that make graphene and graphene nanosheets/binary transition metal oxide (GNS/BTMO) composites apt for their use as anode materials in lithium ion batteries (LIB). GNS/BTMO composites are categorized into three types based on the type of local contact between GNS and BTMO in the composites. These three types are zero-dimensional, one-dimensional and two-dimensional contact composites which are elaborately explained in this article. Amongst the three type, the two dimensional contact composites show superior electrochemical properties (suitable for consideration as anode materials in LIB) than the other two types of contact composites owing to the presence of highly conducting graphene and enhanced local interaction between GNS and BTMO which constrains the restacking of GNS and aggregation of BTMO.

The vanadium redox flow battery (VRB) has received considerable attention due to potential for large-scale energy storage systems suitable for a wide range of renewable energy applications. The key constituent of VRB is an ion exchange membrane that separates two electrolyte solutions, while allowing the conduction of ions. This review summarizes efforts in developing nanostructured membranes with reduced vanadium ion permeability and improved proton conductivity in order to achieve high performance and long life of VRB systems. An overview of the VRB systems and membrane requirements is first introduced. Recent studies on a broad range of nanostructured membranes are then presented, focusing on their properties and performance of VRB employing them. Nafion hybrid membranes containing various nanofillers are discussed mainly in terms of their proton permselectivity. As alternatives to Nafion membrane, nanostructured membranes based on sulfonated hydrocarbon polymers and nonionic materials are also reviewed. The discussion will cover organic-inorganic nanocomposite, amphoteric membranes, and nanofiltration membranes.

Hybrid type supercapacitors store electrical energy through a combination of double layer charging and Faradic processes. The active electrode material plays a pivotal role on the performance of these supercapacitors. In this article, the use of different metal oxide- carbon nanomaterial-conducting polymer ternary nanocomposites as working electrode materials in hybrid supercapacitors is presented.

Developments of new energy sources to surpass conventional fossil fuel have become a serious issue. In the present article, deuterium fusion in hydrogen storage metallic alloys was studied by theoretical calculations. Palladium was selected for the present analysis, and possibility of continuous tetrahedral symmetric condensation of deuterium clusters in the palladium crystal was discussed from the view point of atomic diffusion and reaction time.