Ultra‐Densified TiO₂(B) Anode With Fluid‐Like Compressibility: Enhancing Volumetric Capacity for High‐Performance Supercapacitors

This study develops a highly densified bronze-type TiO₂ (TiO₂(B)) anode to enhance the volumetric energy and power density of supercapacitors. By integrating ultracentrifugation with strategic carbon reduction via annealing, a TiO₂(B) anode with fluid-like lubrication, high compressibility, and improved electrode density is synthesized. The annealing process facilitated a hierarchical nanoporous TiO₂(B) network while preventing agglomeration, achieving an electrode density of 2.24 g cm⁻³, surpassing conventional values. The densified electrode exhibited an exceptional volumetric capacity of 400 mAh cm⁻³, maintaining high-rate performance at 120C. This approach effectively links mechanical and physicochemical properties to electrochemical performance, offering a scalable strategy for optimizing TiO₂(B) anodes. The findings highlight the potential of highly densified TiO₂(B) for hybrid supercapacitors, particularly in applications requiring maximum energy and power density within compact volumes. These advancements hold promise for electric mobility, portable electronics, and renewable energy storage, where efficiency and performance are critical. By demonstrating a method for achieving high-density energy storage, this study provides a framework for next-generation supercapacitor materials. Addressing the growing demands of modern technologies, this research advances high-performance, space-efficient energy storage solutions crucial for future energy applications.