Akademik Veri Yönetim Sistemi
IV. International Conference on Natural Sciences & Technologies, Antalya, Türkiye, 24 Ağustos - 26 Ekim 2022, ss.97
Amorphous iron phosphate has received increasing attention as cathode material for rechargeable lithium-ion batteries due to its being stable, safe, cheap, and having slightly higher theoretical capacity. Due to its possessing poor ionic and electronic conductivity, its practical specific capacity value is lower than the theoretical one [1]. To improve the electrochemical performance of iron phosphate, incorporation of highly conductive carbon additives can be applied [2]. Surface modification is required to increase the interfacial interaction and contact sites between two different materials for improved overall performance. Due to its amphiphilic characteristics, peptide amphiphile (PA) molecules are good candidate for surface modification. Diverse functional groups can be appended to the PA structure for specific purposes.
In this study, short peptide amphiphile (PA) was designed and synthesized for stabilizing and non-covalent surface modification of multiwall-carbon nanotube (MWCNT) and further mineralization of iron phosphate on the MWCNT surface. In the molecular design of the PA, pyrenebutyryl-PPPEK(phosphonoacetyl)-Am, pyrene moiety was used to increase the interaction between MWCNT and PA as a hydrophobic side, while phosphonoacetyl residue was substituted to the periphery of the peptide to provide direct nucleation site and growth of iron phosphate after addition of iron(III) ions. The pyrenebutyryl-PPPEK(phosphonoacetyl)-Am was synthesized via solid-phase peptide synthesize method and characterized via LC-MS. The MWCNTs were first modified non-covalently with pyrenebutyryl-PPPEK-(phosphonoacetyl)-Am. Then, phosphonated-MWCNTs were redispersed in water and iron(III) chloride solution was added at 4°C for the iron dihydrogen phosphate mineralization on MWCNT. After centrifugation, the residue was redispersed and iron(III) chloride and sodium dihydrogen phosphate solutions were added and centrifuged, subsequently. TEM analysis revealed that iron phosphate particles adhered successfully and homogeneously to MWCNTs owing to PA molecules (Figure 1). SEM-EDX analysis indicated the presence of Fe and P atoms on MWCNTs. To produce high-performance battery materials, designed PA can be utilized to produce more advanced battery materials in the future.