Sustainable Anode Design for High-Rate and Flexible Lithium-Ion Batteries

Abstract

Lithium-ion batteries are a widely used class of rechargeable batteries, commonly employed in everyday applications. Beyond their well-established role as a replacement for traditional internal combustion engines in the automotive industry, lithium-ion batteries have garnered significant attention for emerging applications in wearable devices, biomedical equipment, and flexible electronics. Although widely used, conventional lithium-ion batteries are inherently rigid and unable to accommodate mechanical deformations such as bending or folding, which are essential for flexible electronic applications. Beyond structural limitations, they also pose environmental challenges, as the conventional slurry-casting method for electrode fabrication typically relies on toxic solvents. To overcome these limitations, this thesis aimed to design flexible, fast charging, and high-performance anodes while also addressing environmental concerns. The first study demonstrated the integration of niobium oxide as a fast-charging anode material for lithium-ion batteries using a sustainable solvent-free electrode processing technique, achieving mechanical durability and high mass loading, while delivering excellent electrochemical performance even under high-rate charging and discharging conditions. For the second study, hydrothermal/solvothermal synthesis were employed to directly grow titanium dioxide on flexible carbon fiber substrates for the fabrication of a freestanding anode. Given their shared objectives, both studies highlight environmentally friendly aspects while simultaneously enabling flexibility and fast-charging capabilities. In summary, this research seeks to contribute to the advancement of technologies in the expanding rechargeable battery sector.