The ability to store energy in lithium batteries is, in many ways, the key to renewable energy sources such as wind and solar power. If scientists can devise a lithium battery that can charge faster, run longer and more safely, the implications for the burgeoning renewables industry would be profound. Increased storage capacity of lithium batteries, for instance, would increase the range of electric vehicles as well as making the energy storage systems of wind and solar generators much more efficient.
Now, two teams of scientists at the Oak Ridge National Laboratory (ORNL) and Lawrence Berkeley National Laboratory (Berkeley Lab) report that they are making significant progress on the next generation of battery technology, focused on a key battery component, the anode, where electricity comes out. Most current commercial lithium batteries have anodes made of graphite, a form of carbon. However, scientists at ORNL incorporated a special form of the compound titanium dioxide into the anode instead, and they found significant improvements. At the same level of current, it takes the new ORNL battery just six minutes to be 50 percent charged. Even better news? Scientists at ORNL believe that if titanium dioxide proves scalable in batteries, they could be on the market within five years.
The scientists at Berkeley Lab are studying a new anode made from a tailored polymer – a material made of millions of repeating units – that conducts electricity. It also embeds silicon particles, which in turn bind to a lot of lithium ions (much more than graphite anodes can). These improvements give the battery a much greater capacity – the ability to store much more energy – than current designs. Berkley’s new batteries will maintain that increased capacity after hundreds of charge-discharge cycles.
The battery research at ORNL was supported by the Energy Department’s Office of Science and ORNL’s Laboratory Directed Research and Development program. The work at Berkeley Lab was supported by the Department’s Office of Energy Efficiency and Renewable Energy, with additional research and facilities support from the Energy Department’s Office of Science.