#battery cathodes

Professor Paul Braun of Illinois University has come up with a self-assembling three-dimensional nanostructure for battery cathodes(Li-ion and NiMH).The nanostructure allows for faster charging and discharging without forgoing energy storage capacity,and could possibly recharge electric vehicles in less than 2 minutes!The findings were published in the journal Nature Nanotechnology.The batteries in Illinois professor Paul Braun's lab look like any others,but they pack a surprise inside.

Braun's group developed a three-dimensional nanostructure for battery cathodes that allows for dramatically faster charging and discharging without sacrificing energy storage capacity.This new cathode is touted to transmit a magnitude around 400C for lithium battery and 1,000C for NiMH batteries (C stands for charge or discharge rate,where 1C equals a charge in one hour).This means normal lithium-ion batteries could be recharged to 90 percent in just two minutes.The new cathode will also not affect the total capacity of the batteries because of the smaller duration.As Paul Braun says: "...capacitor-like power with battery-like energy."

The performance of typical lithium-ion (Li-ion) or NI-MH rechargeable battery degrades significantly when they are rapidly charged or discharged.Making the active material in the battery a thin film allows for very fast charging and discharging,but reduces the capacity to nearly zero because the active material lacks volume to store energy.But before we put on our happy faces,it should be duly noted that at least now there is no available groundwork for such technology to be utilized.Even so,the exponential rate of charge generated by the system could allow our electric vehicles to be charged from a small source.

Braun is particularly optimistic for the batteries' potential in electric vehicles.Battery life and recharging time are major limitations of electric vehicles.Long-distance road trips can be their own form of start-and-stop driving if the battery only lasts for 100 miles and then requires an hour to recharge.Braun's group wraps a thin film into three-dimensional structure,achieving both high active volume (high capacity) and large current.They have demonstrated battery electrodes that can charge or discharge in a few seconds,10 to 100 times faster than equivalent bulk electrodes,yet can perform normally in existing devices.This kind of performance could lead to phones that charge in seconds or laptops that charge in minutes,as well as high-power lasers and defibrillators that don't need time to power up before or between pulses.