With the reliance of potable electronics on battery power, researchers are exploring various approached to increase the power density of materials for batteries. The majority of batteries for applications, like cell phones, computers, other portable devices, are based on incorporating Lithium. More information of the construction of batteries is available in Reference 1 along with other sources available on the web. The issue is that battery life is too short for most applications and requires frequent recharging during the course of one day. It was not too many years ago that a trip through an airport had every available outlet being used to recharge some device. Technology has improved and battery life has lengthened, but the goal is to keep pushing the limits until devices can continue to work for much more than a day without recharging. There has been a significant amount of research in applying forms of nanocarbon to improve the energy efficiency of batteries.
Over a year ago, there were reports of a graphene technology that will double the life of the Samsung phone batteries. [Ref. 2] The design is considering replacing the graphite anode with graphene-coated silicon resulting in almost doubling the energy density. It is expected that it will be several years before the technology finds its way into mainstream products.
Work has been done in improving the efficiency of lithium based batteries to extend the life of devices that rely on portable power. [Ref. 3] Lithium ion storage is dependent on the structure of the composite materials. Graphene enters into the picture based on its good conductivity and mechanical strength. Using carbon nanotubes with the graphene as spacers between layers, resulting in a superior environment for formation of Fe3O4 microshpheres but also maintaining a proper ration and not allowing an overproduction of the microspheres. Work in China has involved composites that could provide improved performance for lithium-ion batteries.
A recent article is suggesting that a single graphene monolayer could be developed as a support for the electrodes reducing the thickness of the material needed to create the battery. [Ref. 4] The details of the article indicate that anode and cathode are created by electro deposition of zinc and copper on the graphene and are packaged in a graphene based cell. [Ref. 5] This method of generating electrical power, albeit not on the nano scale, goes back at least hundreds of years.
There are other developments that are underway to improve energy storage. Work is being done on Lithium-sulfur batteries that could have superior energy density to the current lithium-ion batteries. [Ref. 6] The comparison indicated that the energy density of Lithium-ion batteries is in the range of 130 to 220 Watt-hours per kilogram. In theory, the Lithium-surfer batteries could be a great as 2,600, which is an order of magnitude greater.
There are continuing developments on the application of graphene to improve the power density of batteries. A search on “graphene batteries” will turn up links to a number of developments that are currently in process. This effort is another example of nanotechnology working to improve every day life.