Recessed deposition of TiN into N-doped carbon as a cathode host for superior Li-S batteries performance
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Date
2018-12-01
Authors
Xing, Zhenyu
Li, Gaoran
Sy, Serubbabel
Chen, Zhongwei
Journal Title
Journal ISSN
Volume Title
Publisher
Elsevier
Abstract
In this work, we put forward a novel cathode host for Li-S batteries by loading titanium nitride (TiN) nanoparticles into the pores of N-doped carbon as a proof-of-concept. The selection of TiN arises from its strong binding ability with polysulfide and its exceptionally high conductivity of 5 × 106 S/m. As for N-doped porous carbon, it provides necessary physical adsorption and extra chemical adsorption sites from the N-doping. Besides the above advantages, the most substantial merit endowed to this structure is the pore-loaded TiN design. The carbon pore size confines the TiN precursors to the nanoscale and prevents otherwise subsequent agglomeration of TiN nanoparticles. Moreover, the pore-loaded TiN design, with fully exposed adsorptive surface and highly dispersed adsorptive sites, guards against the blocking of future sulfur infiltration and Li+ diffusion. The advantages of the TiN loaded N-doped carbon are finally confirmed by electrochemical evaluations. The capacity is found up to be 1338 mAh/g at a current density of 0.2 C and 690 mAh/g at a current density of 5 C (where 1 C = 1672 mAh/g). For durability evaluations, the capacity is maintained at 700 mAh/g after 800 cycles with a mere decay of 0.04% per cycle. Lastly, the feasibility of a high mass loading with 7 mg/cm2 is demonstrated.
Description
The final publication is available at Elsevier via https://dx.doi.org/10.1016/j.nanoen.2018.09.034 © 2018. This manuscript version is made available under the CC-BY-NC-ND 4.0 license https://creativecommons.org/licenses/by-nc-nd/4.0/
Keywords
High mass loading, Lithium sulfur batteries, N-doped porous carbon, Polysulfide adsorption, Recessed deposition of TiN