Implantable devices like pace makers or neurostimulators are powered by lithium batteries whose service life is as low as 10 years. Hence, many patients must undergo a major surgery to check the battery performance and replace the batteries as necessary. A team in Japan has now reported an interesting strategy that would keep using batteries but provides a mechanism for remotely recharging them from outside the body by converting laser light into thermal energy and subsequently to electricity. The main purpose of this study was to show that it is possible to remotely control electrical energy generation by laser light that can be transmitted through living tissue in order to target various bionic applications implanted in the body.
Ultra- or supercapacitors are emerging as a key enabling storage technology for use in fuel-efficient transport as well as in renewable energy. These devices combine the advantages of conventional capacitors - they can rapidly deliver high current densities on demand - and batteries - they can store a large amount of electrical energy. Supercapacitors offer a low-cost alternative source of energy to replace rechargeable batteries. Although the energy density of capacitors is quite low compared to batteries, their power density is much higher, allowing them to provide bursts of electric energy. Researchers have now fabricated novel high-performance sponge supercapacitors using a simple and scalable method. Their results shows that three-dimensional electrodes potentially have a huge advantage over conventional mixed electrode materials.
Many batteries still contain heavy metals such as mercury, lead, cadmium, and nickel, which can contaminate the environment and pose a potential threat to human health when batteries are improperly disposed of. Not only do the billions upon billions of batteries in landfills pose an environmental problem, they also are a complete waste of a potential and cheap raw material. Unfortunately, current recycling methods for many battery types, especially the small consumer type ones, don't make sense from an economical point of view since the recycling costs exceed the recoverable metals value. Researchers in India have carried out research to address the recycling of consumer-type batteries. They report the recovery of pure zinc oxide nanoparticles from spent Zn-Mn dry alkaline batteries.
Lithium-ion batteries have been widely used in many electronic devices that are important to our daily life. However, after a steady improvement of some 10-15% during the last two decades, the energy density of lithium-ion batteries is now approaching its theoretical limit set by the energies of cathode and anode materials used in these batteries. Therefore, in recent years, the pursuit of the next generation of energy storage systems has been intense globally. Among various electrochemical energy storage systems explored to date, the lithium-air (Li-air) battery is one of the most promising technologies, with a theoretical energy density nearly ten times that of conventional lithium-ion batteries. A novel air electrode consisting of an unusual hierarchical arrangement of functionalized graphene sheets delivers an exceptionally high capacity.
The catalytic conversion of chemical to mechanical energy, which is ubiquitous in biological systems, also is the basis for many of the engine systems that nanotechnology researchers are developing. Catalytic 'engines' will be key components of active micron- and sub-micron scale systems for controlled movement, particle assembly, and separations. So far, most of these catalytic micro- and nanomotors use hydrogen peroxide as the fuel. The major problem associated with this is that the produced oxygen bubbles make the observation and detailed study of these motors difficult. Researchers at the Pennsylvania State University have now introduced a new bubble-free, high efficient nanomotor system that involves the operation of a miniaturized copper-platinum nanobattery.
Harvesting unexploited energy in the living environment to power small electronic devices and systems is increasingly attracting the attention of research groups around the world. As device sizes shrink to the micro- and even nanoscale, power consumption also decreases to ever lower levels, i.e. microwatts to milliwatts range. And as research findings have shown over the past few years, it is entirely possible to drive such minuscule devices by directly scavenging energy from their working environment. A recent example is the integration of nanogenerators into the inner surface of tires, demonstrating the possibility of energy harvesting from the motion of automobiles.
Clean and affordable energy generation and storage is one of the most significant challenges that our world is facing in the 21st century. Materials are going to play a crucial role in generation and storage of renewable energy. While searching for new materials for electrical energy storage, materials scientists have discovered a new family of two-dimensional compounds proposed to have unique properties that may lead to ground-breaking advances in energy storage technology. Researchers transformed three dimensional titanium-aluminum carbide into a two dimensional structure with greatly different properties. This work opens the door for a wide range of metal carbide and/or nitride compositions in form of 2-D sheets.
Surface energy is ubiquitous in nature and it plays an important role in many scientific areas such as for instance surface physics, biophysics, surface chemistry, or catalysis. Prior to the area of nanotechnology it has been impractical to consider utilizing surface energy as an energy source because there are few molecules or atoms involved in the surface interaction and the density of surface energy is low. Now, however, due to the lower power consumption requirements of nanoscale devices and the higher specific surface area for nanomaterials it appears attractive to use surface energy at the nanoscale. In new work, researchers have investigated how the flow of water over surfaces coated with graphene could generate small amounts of electricity.