Ti³⁺ Self‐Doped Li₄Ti₅O₁₂ Anchored on N‐Doped Carbon Nanofiber Arrays for Ultrafast Lithium‐Ion Storage

Abstract

The ORCID identification number(s) for the author(s) of this article can be found under https://doi.org/10.1002/smll.201905296. Omnibearing acceleration of charge/ion transfer in Li 4 Ti 5 O 12 (LTO) electrodes is of great significance to achieve advanced high-rate anodes in lithium-ion batteries. Here, a synergistic combination of hydrogenated LTO nanoparticles (H-LTO) and N-doped carbon fibers (NCFs) prepared by an electrodepositionatomic layer deposition method is reported. Binder-free conductive NCFs skeletons are used as strong support for H-LTO, in which Ti 3+ is self-doped along with oxygen vacancies in LTO lattice to realize enhanced intrinsic conductivity. Positive advantages including large surface area, boosted conductivity, and structural stability are obtained in the designed H-LTO@NCF electrode, which is demonstrated with preeminent high-rate capability (128 mAh g −1 at 50 C) and long cycling life up to 10 000 cycles. The full battery assembled by H-LTO@NCFs anode and LiFePO 4 cathode also exhibits outstanding electrochemical performance revealing an encouraging application prospect. This work further demonstrates the effectiveness of self-doping of metal ions on reinforcing the high-rate charge/discharge capability of batteries. www.advancedsciencenews.com

Fabrication of porous lithium titanate self-supporting anode for high performance lithium-ion capacitor

“…Although the active material appears to have a certain degree of agglomeration, it is still fully attached to the CNT substrate ( Fig. S10) [33] . In addition, the XRD result reveals that the crystal structure of p LTO has not changed (Fig.…”

Fast Charging Anode Materials for Lithium‐Ion Batteries: Current Status and Perspectives

“…Doping: Ion doping can enhance the intrinsic electron conductivity and Li + diffusion rate of LTO by introducing defects or vacancies. Many anions and cations, such as Mg 2+ , [140] Ca 2+ , [141] Cu 2+ , [142] Ti 3+ , [143] Zr 4+ , [144] F [145] and Br -, [146] can be doped into the crystal structure of Li 4 Ti 5 O 12 by substituting Li, Ti, or O positions to form various phase structures and improve the pristine properties. For instance, Zr 4+ is doped into LTO via one-step hydrothermal method by Hou and co-workers, [144] which improves the crystallinity and electronic conductivity without changing the basic crystal structure.…”

Designing strategies of advanced electrode materials for high-rate rechargeable batteries

“…Foreign heteroatoms could also affect the electronic conductivity. 112,113 Tu et al synthesized hydrogenated Ti 3+ self-doped Li 4 Ti 5 O 12 nanoparticles with N-doped carbon fibers (H-LTO@NCFs) arrays with the high-rate capacity of 128 mA h g −1 at 50C (Fig. 4b).…”