An illustration of the manganese oxide/cobalt manganese oxide supercapacitor. The bottom purple layer is N-doped graphene while the upper purple layer is manganese oxide/cobalt manganese oxide, with a filter paper separator in between. An induced electric field allows charging and discharging (blue lightning) of the capacitor, creating electrons (fish bones) and OH ions (fish). Shocking Tom (cat) represents shockingly fast electron and ion transport. Image: Xiaonan Hu, Penn State.A new supercapacitor based on manganese oxide could combine the storage capacity of batteries with the high power and fast charging of conventional supercapacitors, according to researchers at Penn State and two universities in China.
"Manganese oxide is definitely a promising material," said Huanyu ‘Larry’ Cheng, assistant professor of engineering science and mechanics and faculty member in the Materials Research Institute at Penn State. "By combining with cobalt manganese oxide, it forms a heterostructure in which we are able to tune the interfacial properties."
The group started with simulations to see how manganese oxide's properties change when coupled with other materials. When they coupled it to a semiconductor, they found that it formed a conductive interface with a low resistance to electron and ion transport. This is important because otherwise the material would be slow to charge.
"Exploring manganese oxide with cobalt manganese oxide as a positive electrode and a form of graphene oxide as a negative electrode yields an asymmetric supercapacitor with high energy density, remarkable power density and excellent cycling stability," said Cheng Zhang, who was a visiting scholar in Cheng's group and the lead author of a paper on this work in Electrochimica Acta.
The researchers have compared their supercapacitor with others, and found that theirs has a much higher energy density and power. They believe that by scaling up its lateral dimensions and thickness, their material has the potential to be used in electric vehicles. So far, though, they have not tried to scale it up.
Instead, their next step will be to tune the interface where the semiconducting and conducting layers meet to achieve even better performance. They want to utilize the supercapacitor as an energy supply for already developed flexible, wearable electronics and sensors, or directly as a self-powered sensor.
This story is adapted from material from Penn State, with editorial changes made by Materials Today. The views expressed in this article do not necessarily represent those of Elsevier. Link to original source.