That’s the word out of the Lawrence Berkeley National Laboratory (Berkeley Lab), where researchers say a new polymer they developed has allowed them to make a silicon anode that absorbs several times the lithium of current designs – and, just as importantly, doesn’t lose its energy-capacity advantage despite charging and discharging over the course of a year.
Lithium-ion batteries typically have anodes made out of graphite. Lithium is added to the graphite during charging and removed as the battery is used. Graphite is a conductive and stable material, but it’s a weakling compared to, say, silicon when it comes to storage capacity. So why not use silicon? Researchers have tried, but their efforts have been frustrated by the instability of the silicon anodes and the resulting loss in capacity over time. (Just recently we reported on Clemson University researchers who believe seaweed could be the basis for a new binder material.)
A lot of brain power has been going into finding a good anode architecture using silicon. But as the Berkeley Lab tells it, nothing has worked nearly as well as their new polyfluorene-based conducting polymers (PFs), which can reportedly lead to battery storage capacities 30 percent greater than what we we see today from lithium-ions. And there’s this added benefit: They’re cheap.
“The whole manufacturing process is low cost and compatible with established manufacturing technologies,” Gao Liu of Berkeley Lab’s Environmental Energy Technologies Division. “The commercial value of the polymer has already been recognized by major companies, and its possible applications extend beyond silicon anodes.”