The B2B platform for full-electric and plug-in hybrid electric vehicles: Industry News

Researchers are continuously looking into improving safety, performance and costs of lithium-ion batteries. Part I of our Batteries Special tells you what could be next on the battery market by introducing the most promising developments Lithium-Air, Lithium-Sulfur and Zinc-Air batteries, as well as a virus that can grow Lithium-Ion batteries.

Since the current lithium-ion battery technology offers still huge potential for improvement many companies and governments spent a lot of money on research to find the “holy grail” of battery chemistries. Researchers claim that they can develop safer materials, with a higher energy density at lower costs. Most recent developments that might get manufacturers close to their ultimate goal of building the battery that would win the race in the electric car industry, however, have also drawbacks.

Lithium-Air batteries

The U.S. technology giant IBM is focusing on lithium-air batteries that have, theoretically, the promise of delivering about 10 times the energy density of lithium-ion batteries by exposing metal and an electrolyte to oxygen to release energy. Some researchers even believe that lithium-air batteries using ambient air could achieve energy densities equivalent to that of gasoline. To develop this technology IBM and its partners are planning to invest around 10 million dollars (7.042 million euros) in the project during the next three years.

Potential problems can be seen in its practical application, since it is only a theoretical concept yet and lithium-air batteries might be considered a “generation after next” technology. Another obstacle is the difficulty to reverse the reaction that provides power, making recharging a challenge. And last but not least, these batteries may also require three to four times as much lithium as current batteries.

Lithium-Sulfur Batteries

The researchers of the University of California Berkeley propose another advanced lithium technology – lithium-sulfur batteries. According to Elton Cairns, a chemical engineering professor at Berkeley, the lithium-sulfur batteries could offer a next step forward. Lithium-sulfur cells have a theoretical potential to deliver about 2,600 watt-hours per kilogram, versus lithium-ion's potential of 585 watt-hours per kilogram, he said.

Research so far has shown better energy densities than lithium-ion chemistries and with 57 cents per kilogram, the material has the additional advantage to be cheap. However, the technology is still in its infancy and cycle life has to be increased as well as the utilisation within the battery. Moreover, lithium-sulfur batteries tend to operate at high temperatures.

Zinc-Air Batteries

A spin-off from Norway’s largest independent research institute in Scandinavia SINTEF is developing innovative zinc-air batteries that are rechargeable and supposed to deliver more than twice the energy of conventional rechargeable designs such as lithium-ion. The technology company, called ReVolt Technology, LLC, has its headquarters in Oregon and is now applying for 30 million dollars in grants from US Department of Energy (DOE) under the American Reinvestment and Recovery Act to accelerate the commercialisation of its large format zinc-air batteries for energy storage and electric vehicle applications.

Zinc batteries are already used in computers and mobiles and the major advantage of zinc is that it is naturally abundant. Zinc batteries have low manufacturing costs and degrade into environmentally safe substances when exhausted, cutting pollution risks and the need for costly battery waste capture programs.

The disadvantages of such batteries are that they rely on ambient conditions, they dry out once exposed to outside air, they have flooding potential as well as limited output, and their active life is short.

Viruses that grow lithium-ion batteries

Another very interesting technology might solve some of the problems that come with lithium-ion batteries from a different angle. Engineers at Massachusetts Institute of Technology (MIT) have manipulated viruses to build both the positively and negatively charged ends of a lithium-ion battery.

This could result in a production of lithium-ion batteries in a test tube. The new batteries produced by a virus would have the same energy capacity and power performance as state-of-the-art rechargeable devices being considered for automotive applications. According to the MIT engineers the technology has additional advantages, since the new batteries could be manufactured with a cheap and environmentally friendly process. Of course, the viruses are a common bacteriophage, which infect bacteria but are harmless to humans.

The technology is far from being ready for the market, however, the research group sees a high potential and intends to pursue research into better batteries using materials with higher voltage and capacitance, such as manganese phosphate and nickel phosphate. Once that next generation is ready, the technology could go into commercial production, they say.