Conventional supercapacitors recharge and discharge faster than most conventional batteries, but the tradeoff is that they lose capacity. This is due to their carbon-based materials that are already difficult to produce.
Using metal-organic frameworks, or MOFs, a team of MIT researchers led by Mircea Dincă has developed a new supercapacitor that outperformed conventional SPs and batteries in both recharge/discharge speed and capacity over time.
Modern electric car batteries use densely packed Li-ion batteries to create bigger and more powerful battery packs capable of powering a car. While such batteries work well, charging them still takes valuable time.
Imagine if an electric car could be recharged in minutes by supercapacitors instead of hours as current Li-ion technology stands. Or, if a cell phone charged in seconds!
Faster, more efficient charging cycles for our most-used electronics would certainly change how we plan (and make excuses for missing calls), but might they also be enough to encourage a mass transition to using electric and hybrid vehicles?
What’s Wrong With Current Supercapacitors?
Supercapacitors charge and recharge at a much faster rate than conventional Li-ion batteries because they use porous carbon as an active electrode (such as activated carbon, nanotubes, or holey graphenes).
The problem, however, is that these carbon-based materials wear out quickly. As a result, energy capacity greatly diminishes after each charge cycle.
In addition, creating the carbon-based electrodes requires expensive chemical solutions and harsh temperatures.
Therefore, although conventional batteries have a slower recharging time, the fact that they maintain their charging capacity over a longer period because makes Li-ion the more efficient choice over carbon-based supercapacitors.
“Results from the team’s research showed that the material lost only 10% charge after 10,000 cycles.”
Moving Away From Carbon-Based Electrodes
MIT Associate professor of Chemistry and lead researcher Mircea Dincă and his team used metal-organic frameworks, or MOFs, to create a supercapacitor with a large surface area.
The new materials are extremely porous and sponge-like. In fact, one gram of the MOF has a surface area equivalent to a football field.
Thus, a supercapacitor made from these ultra-porous materials not only has the potential to store more power, but also recharge and discharge faster without sacrificing capacity.
Results from the team’s research showed that the material lost only 10% charge after 10,000 cycles – an impressive figure competitive with current Li-ion batteries and supercapacitors.