A research team from Colorado State University has devised a lithium-ion battery prototype with features oriented in three dimensions that they say recharges in about 12 minutes compared to the two hours that conventional Li-ion batteries need.
The 3D prototype is about the size of a cell phone battery. It also can be discharged over twice as many times as a conventional lithium ion battery at high discharge rates, researchers say.
Conventional Li-ions are typically composed of a graphite anode (negative electrode) and a lithium compound serves as the cathode (positive electrode). An electrolyte separates the electrodes. The electrodes are stacked in multiple, thin layers. The batteries tend to recharge slowly, have a limited life (about two years), and need special built-in circuits to prevent overheating.
Researchers replaced the graphite anode with nanowires of copper antimonide, a metallic material composed of copper and antimony. The nanowires have an enormous surface area and can store twice as many lithium ions as the same amount of graphite per unit volume. The nanowires also are more chemically stable than graphite and also more heat resistant.
Researchers arranged the nanowires into a tightly-packed, three-dimensional structure resembling the bristles of a hair brush. For the final configuration, the nanowires will be coated with a thin layer of electrolyte and surrounded with conventional cathode material made of lithium.
Researchers think commercial versions of the battery would be thinner and lighter than equivalent Li-ion batteries, because the 3-D version holds more lithium per unit volume.
Chief researcher Amy Prieto co-founded Prieto Battery to commercialize the technology and says that the first 3-D batteries could be available to consumers in as little as two years.
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