Tag Archives: supercapacitor

Used cigarette buds could provide energy storage sollution

A group of South Korean researchers has transformed used cigarette buds into a high-performing energy storing material which could be integrated into computers, handheld devices, electrical vehicles and wind turbines.

Cigarette buds may provide cheap and efficient energy storage.

Interestingly enough, the new material significantly outperformed commercially available carbon, graphene and carbon nanotubes. When you consider the 5.6 trillion used-cigarettes, or 766,571 metric tons that are deposited into the environment worldwide every year, the advantages of such a material become even more evident. Basically, you take a pollution problem and turn it into an advantage.

Co-author of the study Professor Jongheop Yi, from Seoul National University, said:

“Our study has shown that used-cigarette filters can be transformed into a high-performing carbon-based material using a simple one step process, which simultaneously offers a green solution to meeting the energy demands of society. Numerous countries are developing strict regulations to avoid the trillions of toxic and non-biodegradable used-cigarette filters that are disposed of into the environment each year — our method is just one way of achieving this.”

Carbon is the most used element in supercapacitors, due to its relatively low cost, high surface area, high electrical conductivity and long term stability. Now, scientists are focused on improving the capacities of carbon supercapacitors, while also reducing production costs. In this study, they have shown that cellulose acetate fibres (the main component in cigarette filters) could be transformed into a carbon-based material using pyrolysis – a simple burning technique. Following the burning process, the resulting material has with many tiny pores which increase performance as a supercapacitive material.

“A high-performing supercapacitor material should have a large surface area, which can be achieved by incorporating a large number of small pores into the material,” continued Professor Yi. A combination of different pore sizes ensures that the material has high power densities, which is an essential property in a supercapacitor for the fast charging and discharging.”

After composing their theory and creating the material, they set out to test iti n a three-electrode system to see how well it stores energy. The results were remarkable – the material stored a higher amount of electrical energy than commercially available carbon and even had a higher amount of storage compared to graphene and carbon nanotubes, as reported in previous studies. So not only did it outperform commercially available products, it also outperformed other prototypes with much fancier materials.

Scientific Reference: Minzae Lee, Gil-Pyo Kim, Hyeon Don Song, Soomin Park, Jongheop Yi. Preparation of energy storage material derived from a used cigarette filter for a supercapacitor electrode. Nanotechnology, 2014; 25 (34): 345601 DOI: 10.1088/0957-4484/25/34/345601

Cellulose to carbon electrode

Trees could be used for high tech energy storage devices

When you think of timber technology, the first things that come to mind may be constructing homes, wooden tools and, of course, paper. Oregon State University researchers have found, however, that trees could be employed in a process that produces building blocks for supercapacitors – high tech energy storage devices that are considered paramount for the future’s energy needs and applications.

Cellulose to carbon electrode

Photo: Oregon State University

Scientists found that cellulose , which is the most abundant polymer on Earth found in high concentration in trees, can be heated in a furnace in an anaerobic environment (no oxygen – this process is called pyrolysis) with ammonia present, to produce nitrogen-doped, nanoporous carbon membranes – the electrodes of a supercapacitor. The method is quick, low cost and environmentally benign. The only byproduct is methane, which can be then used as a fuel, either in a fuel cell for less carbon emission, or directly burned alone in a heat engine.

What’s truly remarkable is the simplicity of the thermochemical process. The team involved was really stoked to find that nobody else had reported this fundamental chemical reaction. Wood is extremely cheap and readily available, but few could think of any way to make it into a high tech material.

Supercapacitors are extremely important for filling the world’s energy demands of the future. Like a battery, supercapacitors can store vasts amount of energy, only they can charge and discharge incredibly fast, making them particularly useful  in computers and consumer electronics, such as the flash in a digital camera. Where they truly can fill their potential is in heavy industry applications. A wind farm produces enormous quantities of energy, but this supply tends to be intermittent and unreliable. Using huge supercapacitors, megawatt or gigawatt sized wind turbines could be stabilized and ensure base-load.

We could go on forever about the potential applications of supercapacitors, but what brings them down is cost. The Oregon State University researchers demonstrated how to build a key component for supercapacitors easily, cheaply and fast. If supercapacitor cost can be brought down considerably, as a result of findings such as the high tech tree solution, then society might reap great benefits.

The findings were reported in the journal Nano Letters.