High performance lithium-sulfur batteries with facile titanium nitride particles modified separator

• Published in: Materials letters 2018-03, Vol.215, p.91-94
• Main Authors: He, Xuan, Shuai, Yi, Na, Li, Chen, Kanghua, Zhang, Youqiang, Zhang, Zeping, Gan, Fangyu
• Format: Article
• Language: English
• Subjects: Batteries; Conductivity; Decay rate; Design modifications; Discharge; Energy storage; High content sulfur; Lithium; Lithium sulfur batteries; Low conductivity; Materials science; Modified separator; Polysulfides; Potential energy; Rechargeable batteries; Stability; Storage batteries; Strong interactions (field theory); Sulfur; Titanium nitride; Titanium nitride particles
• ISSN: 0167-577X; 1873-4979
• DOI: 10.1016/j.matlet.2017.12.069

[Display omitted] •Micro size Titanium nitride particles were synthesized through a low cost and facile way.•TiN was first applied into the modified separator without any addition of conductive agent.•The TiN modified separator electrode has high discharge capacity (1296 mAh/g). Rechargeable lithium-sulfur (Li-S) batteries are considered as one of the most potential energy storage devices owing to their high theoretical capacity, environmental friendliness and low cost. However, the practical applications of Li-S batteries are restricted by the low conductivity of sulfur, serious dissolution of intermediate polysulfides and fast capacity degradation. Herein, we design a titanium nitride (TiN) modified separator to improve the long-term cycle stability and discharge capacity of Li-S batteries. Strong interaction between the TiN particles and polysulfides can greatly restrain the “shuttle effect” and benefit the cycle stability. With this modified separator, cathodes with a sulfur loading of 78.1% could deliver a high initial discharge capacity of 1296 mAh/g and demonstrate a decay rate of 0.17% per cycle under a high current density of 0.5C. Such superior electrochemical performances ascribe to the high conductivity of TiN and strong affinity between TiN particles and polysulfides.