Improve Batteries with Nanotechnology
Nanotechnology has important contributions to make to the efficiency of energy storage. Note that the types of batteries where nano is making a difference are the ones in cars, laptops, and industrial power backups, rather than the batteries rolling around in your kitchen drawer.
More efficient batteries through nano
So how does nanotechnology help batteries work more efficiently? A key factor in battery efficiency is the power density, or how much electrical power a battery can supply per weight. Of the various types of batteries in use, lithium-ion batteries have the greatest power density, which is why they’re used in laptops and electric cars.
Lithium-ion batteries can store the same amount of power as a nickel-metal hydride battery in a lighter and smaller package. Lithium-ion manufacturers project that their batteries will last about ten years, about four years longer than nickel-metal hydride batteries.
However, lithium-ion batteries are slower to charge and have safety issues. (For example, in one publicized instance a few years ago, lithium-ion batteries in laptop computers caught fire.) Many companies are exploring the use of nanotechnology to change the material used in lithium-ion battery electrodes.
Each company has used its own proprietary material composition, both to reduce the risk of battery fires and to incorporate the capability of a nanostructured surface to increase the surface area on the electrodes. This increase in surface area provides more places for the lithium ions to make contact, allowing greater power density and faster battery discharging and recharging.
We expect the next few steps in nano-based battery improvements to increase power density over conventional lithium-ion batteries by five to ten times. These changes should make laptops lighter, allow them to go a longer time before recharging.
These improvements, however, depend on the manufacturers’ choices. For example, electric cars may be capable of running a few hundred miles between recharges or may contain smaller, less expensive battery packs.
Future nanotechnology improvements to batteries
Using nanotechnology in the manufacture of batteries could increase the power available from a battery through several methods being developed today. For example:
Coating the electrode’s surface with nanoparticles, nanowires, or other nanostructures: Because the anode is where lithium ions are stored when the battery is charged, increasing the number of stored ions increases the stored electrical power.
Various researchers and companies working with lithium-ion batteries have used nanomaterials to develop anodes with a greater density of locations to which lithium ions can attach. This technique increases the surface area of the electrodes, allowing more lithium ions to be stored.
Changing the atoms to which the lithium bonds: Changing these atoms changes the electrochemical reaction, which could give off more energy, increasing the power produced by the battery for any given weight.
These techniques could increase the efficiency of hybrid or electric vehicles by significantly reducing the battery weight or increasing their range.