Ultrafine Titanium Nitride Sheath Decorated Carbon Nanofiber Network Enabling Stable Lithium Metal Anodes

• Published in: Advanced functional materials Vol. 29; no. 46
• Main Authors: Lin, Kui, Qin, Xianying, Liu, Ming, Xu, Xiaofu, Liang, Gemeng, Wu, Junxiong, Kang, Feiyu, Chen, Guohua, Li, Baohua
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc 01-11-2019
• Subjects: Anode effect; Carbon fibers; carbon nanofiber; Charge transfer; Dendritic structure; Diffusion barriers; Electric fields; Electrochemical analysis; Lithium; lithium metal anode; Materials science; Nanofibers; Nanoparticles; Nucleation; Plating; pseudocapacitive behavior; Reaction kinetics; Sheaths; Titanium nitride; Ultrafines; uniform lithium plating
• ISSN: 1616-301X; 1616-3028
• DOI: 10.1002/adfm.201903229

Nonuniform local electric field and few nucleation sites on the reactive interface tend to cause detrimental lithium (Li) dendrites, which incur severe safety hazards and hamper the practical application of Li metal anodes in batteries. Herein, a carbon nanofiber (CNF) mat decorated with ultrafine titanium nitride (TiN) nanoparticles (CNF‐TiN) as both current collector and host material is reported for Li metal anodes. Uniform Li deposition is achieved by a synergetic effect of lithiophilic TiN and 3D CNF configuration with a highly conductive network. Theoretical calculations reveal that Li prefers to be adsorbed onto the TiN sheath with a low diffusion energy barrier, leading to controllable nucleation sites and dendrite‐free Li deposits. Moreover, the pseudocapacitive behavior of TiN identified through kinetics analysis is favorable for ultrafast Li+ storage and the charge transfer process, especially under a high plating/stripping rate. The CNF‐TiN‐modified Li anodes deliver lower nucleation overpotential for Li plating and superior electrochemical performance under a large current density (200 cycles at 3 mA cm−2) and high capacity (100 cycles with 6 mAh cm−2), as well as a long‐running lifespan (>600 h). The CNF‐TiN‐based full cells using lithium iron phosphate and sulfur cathodes exhibit excellent cycling stability.
Carbon nanofiber (CNF) mats decorated with ultrafine titanium nitride (TiN) (CNF‐TiN) are constructed serving as both current collector and host for Li metal anode. Uniform Li deposition is achieved by a synergetic effect of lithiophilic TiN and 3D CNF configuration. CNF‐TiN‐based Li anodes exhibit excellent cycling stability and rate capability in both half and full cells.