Energy Harvesting & Storage Tech Digest - February 2017

Nature’s energy

Scientists at the Iowa State University have developed a tree that could be used to harvest energy from the wind. The system works on piezoelectric principles: as the artificial leaves bend and twist in the wind, piezoelectric materials inside the leaves generate an electric charge. The researchers predict that if the system were the size of a cottonwood tree with 500,000 leaves and subject to ten miles per hour wind it would generate 80W of power. 
Linköping University scientists have turned a rose into a battery. They injected a rose with a material that is then distributed through the rose by natural means and polymerises inside it. This creates a rechargeable battery. The team reports having charged the battery hundreds of times without  any loss of performance. The level of storage achieved is similar to that seen in supercapacitors. The team believes that as it currently is, the device could be used to power ion pumps or certain types of sensors. 

Urea battery

Scientists at Stanford University have created a battery that uses a urea-based aluminium ion electrolyte. The scientists believe it could be used to provide a low-cost solar power storage system. The battery’s electrodes are made from aluminium and graphite. In lab tests the battery went through 1,500 charges with a 45-minute charge time. 

Ingestible that uses gastric acid as power source

Brigham and Women's Hospital and the Massachusetts Institute of Technology have jointly developed an ingestible device which harvests energy from stomach acid and even from the less acidic small intestines. The device can wirelessly send temperature monitoring data (one data packet every 12 seconds) to an external device, for up to a week in tests on large animals. The battery’s electrodes are made of zinc and copper. The team are now working on further increasing the battery life and efficiency. 

Solar power without the panels

Researchers at the University of Minnesota and the University of Milano-Bicocca have embedded silicon nanoparticles in luminescent solar concentrators (LSCs). LSCs work by capturing the useful frequencies of light. The light can then be concentrated to the edges of a window where it can be captured by solar cells.   This work has the potential to be used in the creation of photovoltaic windows and other energy harvesting devices. The team is currently working on incorporating this into real-world semi-transparent photovoltaic windows, with the aim to have a prototype installed by the end of 2017. 

Sodium-ion battery’s anode makeover

A team of Chinese scientists have developed an anode material for a sodium-ion battery that enables it to work at high capacity over hundreds of cycles, overcoming some of the problems that sodium-ion batteries face. The short life of sodium-ion battery anodes is a result of the large size of the sodium ions. The team discovered that by using an antimony-based mineral on a sulphur doped graphene sheet, a sodium-ion battery equipped with the anode could perform at 83% capacity over 900 cycles. 

Nanoflakes for anode

Researchers from Tohoku University and Osaka University have discovered a way to use waste silicon sawdust as a lithium-ion battery anode. They ground the silicon sawdust  into silicon nanoflakes (about 16 nanometres thick), after which they coated the flakes in carbon, and then added the resultant material to the battery anode. The test battery has so far achieved a capacity of 12 mAh/g over 800 cycles. The team thinks this process could be easily used in mass production, and could produce a low-cost lithium-ion battery anode material. 

GM, Honda hydrogen fuel cell factory

General Motors (GM) and Honda announced that they will be opening a manufacturing plant for hydrogen fuel cells, called Fuel Cell System Manufacturing. The companies began work on designing cheap, mass producible hydrogen fuel cells three years ago, and this is the next step towards mass production, Honda claims. The factory is expected to start production in 2020. 

Add this: