Mono-Dispersed Ultra-Long Single-Walled Carbon Nanotubes Enable the Tough, Binder-Free, and Self-Supporting TiNb2O7 Thick Electrode for High-Rate Li-Ion Battery

TiNb2O7 (TNO) is widely regarded as one of the most promising anode materials, owing to its excellent performance; however, its application is impeded by its relatively poor electrical conductivity. In this study, single-walled carbon nanotubes (SWCNTs) are monodispersed in N-methylpyrrolidone (NMP) via surface modification, leveraging the spatial site-barrier effect of dispersant molecules and electrostatic repulsion. The monodispersed SWCNTs form a three-dimensional conductive network, significantly enhancing TNO's conductivity. Binder-free and self-supporting active electrodes are achievable due to the mechanical properties of SWCNTs. Moreover, V3+-doped mesoporous microsphere TNO exhibits a larger specific surface area and an increased number of oxygen vacancies, resulting in a substantial improvement in electrical conductivity. The binder-free electrode maintains a specific capacity of 243.99 mAh g-1 at 5C after 2000 cycles. The LFP-SS//3V-SWCNT5-SS full cell demonstrates a specific capacity of 115.36 mAh g-1 at 0.5C after 180 cycles, and the capacity remains 196.75 mAh g-1 at 2C after 200 cycles. The assembled LFP-SS//3V-SWCNT5-SS full cell delivers a specific capacity of 115.36 mAh g-1 at 0.5C following 180 cycles. In summary, this study presents a method to enhance the material conductivity through the integration of both internal and external modifications, thereby facilitating the application of lithium-ion batteries (LIBs) in wearable electronics.