Browsing by Subject "Template-directed materials"

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Open Access
One-dimensional peptide nanostructure templated growth of iron phosphate nanostructures for lithium-ion battery cathodes
(American Chemical Society, 2016-06) Susapto, H. H.; Kudu, O. U.; Garifullin, R.; Yllmaz, E.; Güler, Mustafa O.
Template-directed synthesis of nanomaterials can provide benefits such as small crystalline size, high surface area, large surface-to-volume ratio, and structural stability. These properties are important for shorter distance in ion/electron movement and better electrode surface/electrolyte contact for energy storage applications. Here nanostructured FePO4 cathode materials were synthesized by using peptide nanostructures as a template inspired by biomineralization process. The amorphous, high surface area FePO4 nanostructures were utilized as a cathode for lithium-ion batteries. Discharge capacity of 155 mAh/g was achieved at C/20 current rate. The superior properties of biotemplated and nanostructured amorphous FePO4 are shown compared to template-free crystalline FePO4.
Open Access
Peptide nanostructure templated growth of iron phosphate nanostrustures for energy storage applications
(2015-12) Susapto, Hepi Hari
The use of primary cells has been replaced with rechargeable batteries due to environmental concerns. Li-ion batteries are examples of the rechargeable batteries that have replaced other types of rechargeable batteries from market due to high capacity, high electrochemical potential, superior energy density, durability, as well as the flexibility in design. Compared to other cathode materials used in Li-ion batteries, the iron oxide (FePO4) is less toxic, environmentally friendly, and less expensive. Inorganic materials can be fabricated by template-directed mineralization to enable control over size and morphology. One-Dimensional (1-D) nanostructures can be used for template directed mineralization method. The nanostructures are particularly interesting as electrode materials due to their high surface area, large surface-to-volume ratio, and favorable structural stability. They provide fast ion/electron transfer by sufficient contact between the active materials and electrolyte. In this thesis, 1-D nanostructures of FePO4 materials with high surface area were synthesized to enhance the efficiency of Li-ion batteries. The synthesis of iron phosphate nanostructures was performed by using peptide amphiphile nanostructures. Iron (III) chloride (FeCl3) was used to trigger the self-assembly of the peptide amphiphile molecules forming nanostructures, which can nucleate FePO4 formation. The electrochemical performance of these nanostructures for Li-ion battery was analyzed. In conclusion, the template directed electrode materials revealed fast ion/electron transfer and sufficient contact between materials and electrolyte. They also exhibited enhanced flexibility leading to higher capacity than the electrode material synthesized without the template.