A team at the Rennselaer Polytechnic Institute has announced that they have utilized blemished graphene paper to devise cheap, fast-charging lithium-ion batteries that are dense enough to render supercapacitors unnecessary.
From TG Daily:
"Li-ion battery technology is magnificent, but truly hampered by its limited power density and its inability to quickly accept or discharge large amounts of energy. By using our defect-engineered graphene paper in the battery architecture, I think we can help overcome this limitation," Nikhil Koratkar, a professor of engineering at Rensselaer, said in a statement.
Energy density refers to the amount of energy that is stored per unit mass, while power density is the maximum power that it is possible to supply per unit of mass. Lithium-ion batteries have high energy density and low power density. That’s why it takes so long to charge cell phone or laptop batteries. They also make it impossible for cars to rely on batteries alone, hence necessitating supercapacitators.
Experts like Elon Musk, CEO of Tesla Motors (NASDAQ: TSLA), have theorized that improving the energy density of supercapacitators would make batteries less critical. However, the Rennselaer team’s achievement restores the battery to prominence, since anodes using their graphene material can charge and discharge roughly 10 times faster than conventional anodes in existing Li-ion batteries.
Interestingly enough, the achievement occurred after the graphene paper was damaged (by being exposed to a laser or a camera flash). The heat caused the graphene surface to become riddled with pores and scars. When used as anode material, ions simply used these ‘shortcuts’ to tunnel through the graphene. Thus, the battery’s power density increased vastly.
Rennselaer has already filed for patent protection, while they get to work pairing up the anode material with a high-power cathode material in order to come up with a full battery.