3D N-doped Li4Ti5O12 nanoribbon networks self-supported on Ti foils as advanced anode for high-performance flexible lithium-ion batteries

Abstract

A novel three dimensional (3D) N-doped Li 4 Ti 5 O 12 (LTO) nanoribbon (N-LTONR) network electrode is synthesized by hydrothermal process and subsequent gas-solid reaction. The presence of self-doped Ti 3+ and oxygen vacancies in LTO lattice further enhances the intrinsic conductivity. The thin nanoribbons (70 nm in width and 20 nm in thickness) are twisted and intertwined to form a 3D conductive network, and can be directly served as flexible electrode for Li ion batteries (LIB) without using any binder and conductive additives. The optimized N-LTONR electrode exhibits excellent high-rate capability, low-temperature performance and cycle stability. It delivers a areal capacity of 0.26 mAh cm −2 at a high current density of 10 mA cm −2 , and has a capacity retention rate of 85.2% after 1000 cycles at 3 mA cm −2 . It also displays excellent low-temperature adaptability and retains 78.3% room temperature-capacity even under − 30 °C, exhibits a low capacity loss (2%) after 100 cycles at 1 mA cm −2 under − 20 °C. In addition, the 3D nanoribbon network electrode possesses good flexibility and has promising potential to be used for flexible and bendable LIBs. • Novel 3D Li 4 Ti 5 O 12 networks consisting of nanoribbons are fabricated on flexible Ti foils. • The as-synthesized 3D Li 4 Ti 5 O 12 nanoribbon networks can be directly used as flexible electrode for high-performance LIBs. • It exhibits much improved high-rate capacity and low-temperature adaptability.