Energy Harvesting & Storage Tech Digest - March 2017

Solid-state battery from lithium-ion battery inventor

A team from the University of Texas headed by John Goodenough, the inventor of the lithium ion battery, has created a solid-state battery cell. The battery is non-combustible and has a long cycle life (1,200 cycles) and fast charge rates (minutes rather than hours). The team also said that their battery’s density is three times that of lithium ion batteries, making it a good candidate for use in electric cars. These advancements are possible by replacing the traditional liquid electrolytes of batteries with a glass electrolyte. This allows for alkali-metal anodes which do not suffer the same gradually debilitating effects as traditional anodes. The battery can operate in temperatures as low as minus 60 degrees Celsius. The team is continuing its work with a view to working with battery makers to test and develop the battery of use in electric vehicles and energy storage devices. 

Sony patent for wireless charging systems

Sony has filed a patent  for an antenna system that would allow wireless  power and data transfer between consumer electronic devices. Multiple antenna systems would be involved. The patent discusses issues of security and how antenna locations would be displayed. Little other information on the fundamental workings of the tech is explained in the patent. 

Turning heat into electricity

Researchers at Virginia Tech have constructed a device that can convert wasted heat into electricity. The thermo-magneto-electric generator uses soft magnets made of gadolinium. This is attached to a flexible plastic cantilever which allows the soft magnet to attach to a hard magnet attached to a heat source such as a computer’s CPU. When the magnet reaches a certain temperature, the soft magnet demagnetises and detaches from the hard magnet through the action of the cantilever. When the soft magnet has cooled, it will again magnetise and attach to the hard magnet creating a circular process. The piezoelectric cantilever converts the up down motion of the magnet into usable electricity. The system can produce electricity with magnet temperatures of 50 to 60 Celsius. The scientists see the small device being used to power networks of sensors in smart-homes. 

Reducing platinum could make for cheaper electrolysers

The expensive metal platinum is widely used as a catalyst in electrolysers that store electrical energy as hydrogen bond energy. A team of researchers from Finnish Aalto University has developed a method for manufacturing electrolysers which they say uses one-hundredth the amount of platinum, so their method would significantly reduce the price of electrocatalysis. The team emphasise that this is simply a proof of concept and that further tests need to be carried out to see if it would work outside the lab in the higher temperatures required in industrial use cases.

Thin film electrode could help with storing solar power

Researchers at RMIT University in Australia have developed a graphene-based prototype flexible thin film electrode which it claims could increase the capacity of existing integrated storage technologies by up to 3000 percent. The electrode has been made to work with supercapacitors which have potential for use in solar harvesting but lack capacity. The researchers created fractal patterns on the electrodes to make full use of the available space for more efficient energy storage. The scientists say that as the prototype uses a thin film design it has many applications including an on chip energy harvesting and storage solution, or for use in windows, smart phones or smart watches.  

Nanoparticles could improve solar harvesting technology

Scientists at Imperial College London (ICL) have been investigating the use of metal (silver) nanoparticles to act as photocatalysts in chemical reactions such as artificial photosynthesis. The nanoparticles have been shown to act as good light transporters to provide energy to an artificial chemical reaction. In tests the team noticed areas of a nanomaterial surface where chemical reactions were occurring. These locations were considered suitable places for transferring energy to chemical reactions as suggested by the movement of gold nanoparticles (acting as markers) across the surface of the material. The team sees this finding as having possible applications in improving solar panels’ harvesting potential, or even to be used to help breakdown pollutants such as pesticides in water.

Thin battery

Scientists from NASA and the University of Miami have created a solid-state battery prototype, the thinness of which – 2-3 millimetres – would make it suitable for use in Cubesats, small secondary payloads on rockets. The scientists say their battery would take up just a third of the space of currently used batteries. Their new batteries are made of compressed and fired carbon fibre layers, between which a solid-state electrolyte is placed. The team sees this being added to walls in buildings during construction to act as a secondary power source. 

Cool batteries

Scientists at ETH Zurich and IBM Research Zurich have developed a redox flow battery that can keep itself from overheating. The miniature battery they created keeps a chip cool by pumping two liquid electrolytes into the battery through 3D printed nano-channels. The battery can generate 1.4 watts per square centimetre, using 0.4 watts to power the pump. The ratio of heat produced to heat lost is low meaning the chip keeps cool.

Getting electricity from plants

Plant-e, a Dutch company harvesting electricity from plants, is using its system to power 300 LED streetlights at two locations in the Netherlands. The energy harvesting technology works by utilizing the electrons produced during the breakdown by bacteria of excreted waste sugars in soil. Installing electrodes into the soil allows for electrical conduction. The product Plant-e is providing for the trial is a specially manufactured plant pot that is able to tap into this electrical potential in the soil. The company is also developing a kit to be used in wetlands.

New method to manufacture perovskite thin film

Scientists at the U.S. Department of Energy's (DOE) National Renewable Energy Laboratory (NREL) have developed a type of perovskite ink that enables the production of perovskite thin films for high-efficiency solar cells. The ink enlarges the critical window during perovskite thin film manufacture when an antisolvent must be added to extract precursor materials. Without extraction, these materials negatively affect crystal quality. The window in current manufacture is only open for a few seconds; the scientists’ window was able to stay open for as long as eight minutes. It was also able to reduce the time required to heat treat the perovskite. The team used their method to make a 12.6 square centimetre four-cell perovskite module. 11.1 square centimetres were active in converting sunlight to energy and showed efficiency of 13.3 percent. The scientists hope that this could make the manufacture of perovskite thin film solar cells more attractive to large-scale manufacturers. 

Add this: