A Robust Ternary Heterostructured Electrocatalyst with Conformal Graphene Chainmail for Expediting Bi‐Directional Sulfur Redox in Li–S Batteries. (31st March 2021)

• Record Type: Journal Article
• Authors: Cai, Jingsheng; Sun, Zhongti; Cai, Wenlong; Wei, Nan; Fan, Yuxin; Liu, Zhongfan; Zhang, Qiang; Sun, Jingyu
• Is Part Of: Advanced functional materials. Volume 31:Number 23(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-03-31
• Subjects: bidirectional conversion reactions -- graphene chainmail -- Li S batteries -- operando X‐ray diffraction -- ternary heterostructure; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adfm.202100586
• Languages: English
• ISSNs: 1616-301X

Abstract

Abstract: Designing high‐performance electrocatalysts for boosting aprotic electrochemistry is of vital importance to drive longevous Li–S batteries. Nevertheless, investigations on probing the electrocatalytic endurance and protecting the catalyst activity yet remain elusive. Here, a ternary graphene‐TiO2 /TiN (G‐TiO2 /TiN) heterostructure affording conformal graphene chainmail is presented as an efficient and robust electrocatalyst for expediting sulfur redox kinetics. The G‐TiO2 /TiN heterostructure synergizes adsorptive TiO2, catalytic TiN, and conductive graphene armor, thus enabling abundant anchoring points for polysulfides and sustained active sites to allow smooth bi‐directional electrocatalysis. Encouragingly, in situ crafted graphene chainmail ensures favorable protection of inner TiO2 /TiN to retain their catalytic robustness towards durable sulfur chemistry. As expected, sulfur cathodes mediated by ternary G‐TiO2 /TiN harvest an impressive rate capability (698.8 mAh g −1 at 5.0 C), favorable cycling stability (a low decay of 0.054% per cycle within 1000 cycles), and satisfactory areal capacity under elevated loading (delivering 8.63 mAh cm −2 at a sulfur loading of 10.4 mg cm −2 ). The ternary heterostructure design offers an in‐depth insight into the electrocatalyst manipulation and protection toward long lifespan Li–S batteries. Abstract : A ternary graphene‐TiO2 /TiN heterostructure affording conformal graphene chainmail with excellent electrical conductivity, attractive polysulfide affinity, remarkable electrocatalysis behavior, and commendable graphitic protection targeting longevous Li–S batteries is presented.