
Graphene hybrids (left) made from metal organic frameworks (MOF) and graphenic acid make an excellent positive electrode for supercapacitors, which thus achieve an energy density similar to that of nickel-metal hydride batteries.
Image: J. Kolleboyina / IITJ
Powerful graphene hybrid material for highly efficient supercapacitors
Hybrid materials: Nature is the role model
The researchers are betting on a new strategy to overcome the performance limits of standard materials – they utilize hybrid materials. “Nature is full of highly complex, evolutionarily optimized hybrid materials – bones and teeth are examples. Their mechanical properties, such as hardness and elasticity were optimized through the combination of various materials by nature,” says Roland Fischer.
The abstract idea of combining basic materials was transferred to supercapacitors by the research team. As a basis, they used the novel positive electrode of the storage unit with chemically modified graphene and combined it with a nano-structured metal organic framework, a so-called MOF.
Powerful and stable
Decisive for the performance of graphene hybrids are on the one hand a large specific surface and controllable pore sizes and on the other hand a high electrical conductivity. “The high performance capabilities of the material is based on the combination of the microporous MOFs with the conductive graphene acid,” explains first author Jayaramulu Kolleboyina, a former guest scientist working with Roland Fischer.
A large surface is important for good supercapacitors. It allows for the collection of a respectively large number of charge carriers within the material – this is the basic principle for the storage of electrical energy.
Through skillful material design, the researchers achieved the feat of linking the graphene acid with the MOFs. The resulting hybrid MOFs have a very large inner surface of up to 900 square meters per gram and are highly performant as positive electrodes in a supercapacitor.
Long stability
However, that is not the only advantage of the new material. To achieve a chemically stable hybrid, one needs strong chemical bonds between the components. The bonds are apparently the same as those between amino acids in proteins, according to Fischer: “In fact, we have connected the graphene acid with a MOF-amino acid, which creates a type of peptide bond.”
The stable connection between the nano-structured components has huge advantages in terms of long term stability: The more stable the bonds, the more charging and discharging cycles are possible without significant performance impairment.
For comparison: A classic lithium accumulator has a useful life of around 5,000 cycles. The new cell developed by the TUM researchers retains close to 90 percent capacity even after 10,000 cycles.
International network of experts
Fischer emphasizes how important the unfettered international cooperation the researchers controlled themselves was when it came to the development of the new supercapacitor. Accordingly, Jayaramulu Kolleboyina built the team. He was a guest scientist from India invited by the Alexander von Humboldt Foundation and who by now is the head of the chemistry department at the newly established Indian Institute of Technology in Jammu.
“Our team also networked with electro-chemistry and battery research experts in Barcelona as well as graphene derivate experts from the Czech Republic,” reports Fischer. “Furthermore, we have integrated partners from the USA and Australia. This wonderful, international co-operation promises much for the future.”
The Latest Updates from Bing News & Google News
Go deeper with Bing News on:
Supercapacitors
- IISc researchers design tiny supercapacitor capable of storing large amount of electric charge
Researchers at the Indian Institute of Science (IISc) have designed a novel, tiny device capable of storing an enormous amount of electric charge. The ultra-micro supercapacitor is also much smaller a ...
- IISc researchers design supercapacitor capable of storing enormous electric charge
Researchers at the Indian Institute of Science (IISc) have designed a novel, tiny device capable of storing an enormous amount of electric charge. The ultra-micro supercapacitor is also much smaller ...
- A novel ultramicro supercapacitor with ultrahigh charge storage capability
Researchers at the Department of Instrumentation and Applied Physics (IAP), Indian Institute of Science (IISc), have designed a novel ultramicro supercapacitor, a tiny device capable of storing an ...
- Novel supercapacitor for energy storage applications
It is also much smaller and more compact than existing supercapacitors and can potentially be used in many devices ranging from streetlights to consumer electronics, electric cars and medical devices.
- IISc’s tiny new device to store enormous energy has uses from streetlights to e-Cars
BENGALURU: Researchers at IISc’s department of instrumentation and applied physics (IAP) have designed a novel ultra-micro supercapacitor, a tiny device capable of storing an enormous amount of ...
Go deeper with Google Headlines on:
Supercapacitors
[google_news title=”” keyword=”supercapacitors” num_posts=”5″ blurb_length=”0″ show_thumb=”left”]
Go deeper with Bing News on:
Graphene supercapacitors
- IISc researchers design tiny supercapacitor capable of storing large amount of electric charge
Researchers at the Indian Institute of Science (IISc) have designed a novel, tiny device capable of storing an enormous amount of electric charge. The ultra-micro supercapacitor is also much smaller a ...
- IISc researchers design supercapacitor capable of storing enormous electric charge
Researchers at the Indian Institute of Science (IISc) have designed a novel, tiny device capable of storing an enormous amount of electric charge. The ultra-micro supercapacitor is also much smaller ...
- A novel ultramicro supercapacitor with ultrahigh charge storage capability
Researchers at the Department of Instrumentation and Applied Physics (IAP), Indian Institute of Science (IISc), have designed a novel ultramicro supercapacitor, a tiny device capable of storing an ...
- Novel supercapacitor for energy storage applications
and graphene – to increase electron mobility – which are then connected to gold contacts. A solid gel electrolyte is used between the two FET electrodes to build a solid-state supercapacitor. The ...
- Researchers synthesize graphene using intense light
DGIST Professor Yoonkyu Lee's research team used intense light on the surface of a copper wire to synthesize graphene, thereby increasing the production rate and lowering the production cost of the ...
Go deeper with Google Headlines on:
Graphene supercapacitors
[google_news title=”” keyword=”graphene supercapacitors” num_posts=”5″ blurb_length=”0″ show_thumb=”left”]