Lithium titanium oxide materials for hybrid supercapacitor applications
Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
The objective of this thesis was to investigate the suitability of some different Li4Ti5O12 materials as a negative electrode in hybrid supercapacitors. A hybrid supercapacitor is a combination of a battery and an electric double-layer capacitor that uses both a battery material and a capacitor material in the same device. The target for these combination devices is to bridge the performance gap between batteries and capacitors and enable both high energy and power density. To achieve this, materials with high capacity as well as high rate capability are needed. To improve the rate of the commonly slow battery materials nanosizing has been found to be an effective solution.
This study shows that Li4Ti5O12 has a significantly higher experimental capacity than the most common capacitor material, activated carbon. The capacity remained high even at high discharge rates due to a successful nanostructuring that increased the accessibility of the material and shortened the diffusion distance for the ions, leading to a much improved power performance compared with the bulk material. The use of a nanostructured Li4Ti5O12 material in a hybrid device together with activated carbon was estimated to double the energy density compared to an electric double-layer capacitor and maintain the same good power performance. To further increase the energy density also improved materials for the positive electrode should be investigated.
Place, publisher, year, edition, pages
2016. , 59 p.
UPTEC Q, ISSN 1401-5773 ; 16017
Nanomaterials, LTO, energy storage, supercapacitors
Materials Chemistry Composite Science and Engineering
IdentifiersURN: urn:nbn:se:uu:diva-301977OAI: oai:DiVA.org:uu-301977DiVA: diva2:955939
Tokyo University of Agriculture and Technology
Master Programme in Materials Engineering
Jang, Hwamyung, Dr.Iwama, Etsuro, Dr.Naoi, Katsuhiko, Prof.
Kassman Rudolphi, ÅsaBrandell, Daniel