Non-rechargeable batteries, which depend on a reaction between aluminum and oxygen, can store significantly more energy than conventional lithium-ion batteries. The biggest limitation of such aluminum-air batteries is their short shelf life. An improved battery design could help eliminate this limitation. Aluminum and air batteries are based on the property of aluminum to corrode, which is also their weak spot:
4 Al + 3 O2 + 6H2O → 4 Al (OH)3
While an aluminum-air battery is not used, its electrodes corrode causing unwanted discharge. This self-discharge drastically shortens the shelf life of the battery. Brandon Hopkins, of the Massachusetts Institute of Technology in Cambridge, and his colleagues developed an aluminum-air battery that uses a conventional electrolyte during operation. When stored, however, the electrolyte is replaced by oil. Their article was recently published in the journal Science.
The new battery reaches a storage capacity of almost 900 Wh / kg. This makes the prototype comparable to other aluminum-air batteries. In contrast, the new corrosion protection extends the storage time 10,000-fold. The authors suggest that such a battery could be used in long-range drones and grid-independent power generation. At Frontis Energy, we believe that batteries with high storage capacity and durability can be used almost anywhere, for example for sensors and other applications.
(Photo: George Hodan)
Fuel cells are the devices that convert chemical energy directly into electrical energy. The process combines hydrogen and oxygen produce water& electricity as main products. Fuel cells are similar to batteries in that they produce electricity but also different in that a fuel is supplied without a charge-discharge cycle. Like batteries, they are portable and developed by technological experts. The cells can be used with a variety of fuels like ethanol, methanol, methane, and more.
Here are the advantages of hydrogen fuel cells –
- The cells are efficient when compared to the conventional forms of producing energy.
- Hydrogen fuel cells operate silently.
- Fuel cells eliminate pollution by switching from burning of fossil fuels to hydrogen.
- Fuel cells last longer than batteries because they use chemical fuels to produce energy.
- Hydrogen fuel cells are grid-independent and can be used anywhere.
Components of Fuel Cells. A fuel cell converts chemical energy into electrical energy, much like a battery. But unlike batteries, they produce electricity from external supplies of fuels to the anode and oxidants to the cathode. Fuel cells can operate virtually continuously as long as the necessary fuel is supplied. Electrolytes are the major components of the fuel cells and keep that allow ion exchange. Fuel cells also have electrodes that are catalysts of the electrical chemical reaction.
Fuel for Fuel Cells. Fuel cells can operate using a variety of fuels like hydrogen, ethanol, methanol, and methane. Fossil fuels like methane are extracted from underground and converted into a hydrogen rich stream. There is also a huge abundant amount of hydrogen in water which can be used for the hydrogen power supply .For higher voltages, fuel cells can be stacked. Fuel cells can power anything from microchips to buses, boats, and buildings.
Fuel Cell Efficiency. The fuel cells are much more efficient than conventional power generation. This is because conventional power is generated be converting chemical energy into heat, mechanical energy and lastly into electrical energy. Fuel cells are converting energy directly into electrical energy and are much more efficient.
Fuels cells are a promising technology and already a source of electricity for buildings and vehicles. The devices operate best with pure hydrogen. In contrast, fossil fuel reserves are in limited and the energy future of the world needs to include several renewable alternatives to our declining resources. Hydrogen is the most abundant element present in the universe and serves as the fuel for nuclear fusion in the sun. Due to this abundance, hydrogen fuel cells are the best green energy source.
In todays Li-ion batteries, cobalt oxide cathodes improve performance and durability. While, such cobalt cathodes show the same performance as nickel oxide cathodes, they come at a higher price. Nickel cathodes, in turn, crack and dissolve quickly, which reduces their lifespan. Nevertheless, nickel cathodes are very popular because they are so cheap.
Now, the research team led by Jaephil Cho of the Ulsan National Institute of Science and Technology in South Korea has developed a cathode made of more than 80% nickel. The researchers reported in the journal Energy & Environmental Science that a cathode coated with nanocrystals of cobalt aged more slowly than conventional nickel cathodes. After recharging 400 times at room temperature, the battery was able to retain 86% of its original capacity.
The novel nickel cathodes could help meet the growing demand for rechargeable batteries in electric vehicles if cobalt prices rise in the future.