Heterogeneous MoSe<sub>2</sub>/Nitrogen‐Doped‐Carbon Nanoarrays: Engineering Atomic Interface for Potassium‐Ion Storage
Da Xu, Ling Chen, Xiaozhi Su, Hongliang Jiang, Hongliang Jiang, Cheng Lian, Honglai Liu, Long Chen, Yanjie Hu, Hao Jiang, Hao Jiang, Chunzhong Li
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 MoSe 2 has been identified as a promising anode material for KIBs; however, its electrochemical reversibility remains a big challenge. Herein, heterogenous MoSe 2 /N‐doped carbon nanoarrays demonstrate a brilliant performance as KIBs anode materials. The as‐formed hetero‐interface weakens the KSe bond of discharged products (K 2 Se), the length of KSe bond is stretched by 3.9% with an enlargement of 19.2% in angle compared with pure K 2 Se, greatly promoting the regeneration of MoSe bond during charge. Moreover, the atomically inter‐overlapping feature leads to an expanded MoSe 2 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.