Heterogeneous MoSe2/Nitrogen‐Doped‐Carbon Nanoarrays: Engineering Atomic Interface for Potassium‐Ion Storage. (9th November 2021)

• Record Type: Journal Article
• Authors: Xu, Da; Chen, Ling; Su, Xiaozhi; Jiang, Hongliang; Lian, Cheng; Liu, Honglai; Chen, Long; Hu, Yanjie; Jiang, Hao; Li, Chunzhong
• Is Part Of: Advanced functional materials. Volume 32:Number 8(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-11-09
• Subjects: electrochemical reversibility -- geometric structures -- heterogenous interfaces -- K‐ion batteries -- MoSe 2; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adfm.202110223
• Languages: English
• ISSNs: 1616-301X

Abstract

Abstract: Owing to the lower price and higher safety, developing high‐performance K‐ion batteries (KIBs) is of great significance as an alternative to Li‐ion batteries. High‐energy‐density MoSe2 has been identified as a promising anode material for KIBs; however, its electrochemical reversibility remains a big challenge. Herein, heterogenous MoSe2 /N‐doped carbon nanoarrays demonstrate a brilliant performance as KIBs anode materials. The as‐formed hetero‐interface weakens the KSe bond of discharged products (K2 Se), the length of KSe bond is stretched by 3.9% with an enlargement of 19.2% in angle compared with pure K2 Se, greatly promoting the regeneration of MoSe bond during charge. Moreover, the atomically inter‐overlapping feature leads to an expanded MoSe2 interlayer distance of 1.20 nm that enables a much faster K‐ion diffusion. Consequently, this nanoarray delivers an unprecedented K‐ion storage performance, that is, a capacity of 402 mAh g −1 at 0.2 A g −1 over 200 cycles, and a long cycle life over 1000 cycles at 1.0 A g −1 with 307 mAh g −1 capacity retention. Abstract : The heterogenous MoSe2 /N‐doped carbon nanoarrays demonstrate a brilliant performance as K‐ion batteries anode materials with greatly enhanced reversibility. The as‐formed heterointerface greatly weakens the KSe bond of the discharge product (K2 Se) by optimizing its geometric structure, leading to the easy regeneration of the MoSe bond. The K‐ion storage mechanism and structure‐performance relationship are further clarified during de‐/potassiation.