Editorial Feature

Integrating Twisted Graphene into Energy Storage Devices

Twisted graphene is an intriguing contender for applications in next-generation energy conversion and storage devices due to its intrinsic physical qualities and the high degree of tunability of its electronic properties.

Image Credit: MZinchenko/Shutterstock.com

What is Twisted Graphene?

Twisted graphene, also known as twisted bilayer graphene, is a unique structure that may be created by stacking two layers of graphene at a tiny angle, often somewhere between one and two degrees. Because the hexagonal lattices of the two graphene layers are not entirely aligned, a new unit cell with a larger size and a moiré pattern is produced.

The resulting structure of twisted graphene is particularly fascinating from a scientific point of view due to the fact that it possesses a range of unusual physical and electrical properties that are not found in either single-layer graphene or graphite in its bulk form. These characteristics are the result of interlayer coupling that occurs between the two graphene layers, which is mostly determined by the twist angle of the graphene layers.

Twisted graphene has a flat electronic band structure at particular "magic" twist angles, such as 1.1 degrees and 1.8 degrees, where the energy levels of the electrons are spread out over a large range of momentum space, resulting in a near-zero density of states. This results in a variety of intriguing phenomena, such as Mott insulator behavior, superconductivity, and topological states.

Batteries and Supercapacitors

Energy is stored in batteries as chemical potential energy, which is transformed into electrical energy when needed. To enhance the amount of energy that can be stored, battery electrodes are often comprised of materials having a high surface area, such as activated carbon or metal oxides. Because of the moiré pattern generated by the two layers, twisted graphene has a huge surface area, which improves its ability to store energy. Furthermore, the flat electrical band structure at the magic angles could be used to increase battery and supercapacitor performance.

Supercapacitors, on the other hand, store energy in the form of electrical charges that can be released quickly. To maximize capacitance, supercapacitors' electrodes are often composed of materials with high electrical conductivity and surface area. Due to its unique electronic properties, twisted graphene has a high electrical conductivity, and its enormous surface area can also increase the material's capacitance.

For example, researchers from India's Jawaharlal Nehru Centre for Advanced Scientific Research reported using twisted multilayer graphene to create an ultrafast supercapacitor with an ultrahigh-frequency response in the order of 10,000 Hz, the highest reported for any supercapacitor to date.

Solar Cells

In solar cells, sunlight is transformed into electrical energy by absorbing photons in a material having a bandgap that matches the energy of the photons. The absorbed energy excites the material, which can then be collected as an electrical current. A solar cell's performance is determined by various parameters, including the material's bandgap, electrical conductivity, and light absorption.

The moiré pattern of twisted graphene can behave as a photonic crystal, increasing light absorption and improving solar cell efficiency. Furthermore, the flat electronic band structure at the magic angles may result in better charge carrier mobility, critical for effective charge separation and collection in solar cells.

The photovoltage of a 10° twisted bilayer graphene photodetector demonstrates a sevenfold photovoltage improvement (700%) at the best incident angle, according to researchers from Nankai University in Tianjin.

Fuel Cells

Fuel cells are electrochemical devices that directly transform chemical energy into electrical energy. They are made up of an electrolyte as well as two electrodes: an anode and a cathode. The fuel is oxidized in the anode to produce electrons and protons. Protons move through the electrolyte to the cathode while electrons travel through an external circuit, providing an electrical current. Protons react with oxygen in the cathode to generate water, completing the electrochemical reaction.

Because of its unique electronic properties, twisted graphene has a high electrical conductivity, which can improve the performance of fuel cells. Furthermore, the huge surface area of twisted graphene can increase the surface area of the electrodes and enable reactant adsorption, enhancing fuel cell efficiency.

Water Splitting

Twisted graphene could be used in water-splitting applications due to its large surface area. Twisted graphene's moiré pattern can also serve as a template for forming catalytic nanoparticles, increasing the efficiency of the water-splitting process.

Thermoelectric Materials

Due to its unique electrical characteristics, twisted graphene could be a viable material for thermoelectric applications. The flat electronic band structure at the magic angles may result in a high Seebeck coefficient, which is necessary for converting heat to electricity.

Challenges and Opportunities

The longevity of energy storage can be improved by using twisted graphene due to its mechanical and chemical stability. Compared to other high-performance energy storage materials, the production cost of twisted graphene is significantly lower, making it a promising candidate for widespread use.

However, before twisted graphene is used in a practical energy storage system, numerous hurdles must be cleared. For instance, there is still a technical challenge in the mass production of high-quality twisted graphene. The complexity of the electrical environment generated by twisted graphene's moiré pattern adds another layer of difficulty to the challenge of developing an efficient energy storage device based on this material.

Overall, research on solar cells using twisted graphene is exciting and growing rapidly. To fully understand the potential of this material and to optimize its use in practical applications, more research and development is required.

Continue reading: What is Twisted Graphene?

References and Further Reading

Gupta, N, Mogera, et al. (2022) Ultrafast planar microsupercapacitor based on defect-free twisted multilayer graphene, Materials Research Bulletin. p. 111841 https://www.sciencedirect.com/science/article/abs/pii/S0025540822001143?via%3Dihub

Xin, Wei, et al. (2016) "Photovoltage Enhancement in Twisted‐Bilayer Graphene Using Surface Plasmon Resonance." Advanced Optical Materials. pp. 1703-1710. https://onlinelibrary.wiley.com/doi/10.1002/adom.201600278

Mogera, Umesha, and Giridhar U. Kulkarni. (2020) "A new twist in graphene research: Twisted graphene." Carbon. pp. 470-487. https://www.sciencedirect.com/science/article/abs/pii/S0008622319309625?via%3Dihub

Disclaimer: The views expressed here are those of the author expressed in their private capacity and do not necessarily represent the views of AZoM.com Limited T/A AZoNetwork the owner and operator of this website. This disclaimer forms part of the Terms and conditions of use of this website.

Akanksha Urade

Written by

Akanksha Urade

Akanksha is a Ph.D. research scholar at the Indian Institute of Technology, Roorkee, India. Her research area broadly includes Graphene synthesis by the chemical vapor deposition technique. Akanksha also likes to write science articles regarding the latest research in 2D materials, especially Graphene, and reads relevant papers to understand what is being claimed and try to present it in a simplified way. Her goal is to help every reader understand Graphene Technology, regardless of whether their background is scientific or non-scientific. She believes that everyone can learn - provided it's taught well.

Citations

Please use one of the following formats to cite this article in your essay, paper or report:

  • APA

    Akanksha, Akanksha. (2023, June 19). Integrating Twisted Graphene into Energy Storage Devices. AZoNano. Retrieved on May 21, 2024 from https://www.azonano.com/article.aspx?ArticleID=6472.

  • MLA

    Akanksha, Akanksha. "Integrating Twisted Graphene into Energy Storage Devices". AZoNano. 21 May 2024. <https://www.azonano.com/article.aspx?ArticleID=6472>.

  • Chicago

    Akanksha, Akanksha. "Integrating Twisted Graphene into Energy Storage Devices". AZoNano. https://www.azonano.com/article.aspx?ArticleID=6472. (accessed May 21, 2024).

  • Harvard

    Akanksha, Akanksha. 2023. Integrating Twisted Graphene into Energy Storage Devices. AZoNano, viewed 21 May 2024, https://www.azonano.com/article.aspx?ArticleID=6472.

Tell Us What You Think

Do you have a review, update or anything you would like to add to this article?

Leave your feedback
Your comment type
Submit

While we only use edited and approved content for Azthena answers, it may on occasions provide incorrect responses. Please confirm any data provided with the related suppliers or authors. We do not provide medical advice, if you search for medical information you must always consult a medical professional before acting on any information provided.

Your questions, but not your email details will be shared with OpenAI and retained for 30 days in accordance with their privacy principles.

Please do not ask questions that use sensitive or confidential information.

Read the full Terms & Conditions.