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Controllable Heterojunctions with a Semicoherent Phase Boundary Boosting the Potassium Storage of CoSe 2 /FeSe 2
Author(s) -
Shan Hui,
Qin Jian,
Ding Yingchun,
Sari Hirbod Maleki Kheimeh,
Song Xuexia,
Liu Wen,
Hao Youchen,
Wang Jingjing,
Xie Chong,
Zhang Jiujun,
Li Xifei
Publication year - 2021
Publication title -
advanced materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 10.707
H-Index - 527
eISSN - 1521-4095
pISSN - 0935-9648
DOI - 10.1002/adma.202102471
Subject(s) - heterojunction , materials science , potassium , energy storage , anode , metal , lattice (music) , chemical engineering , condensed matter physics , chemical physics , optoelectronics , electrode , chemistry , thermodynamics , metallurgy , power (physics) , physics , engineering , acoustics
Heterostructure construction is an efficient method for reinforcing K + storage of transition metal selenides. The spontaneously developed internal electric fields give a strong boost to charge transport and significantly reduce the activation energy. Nevertheless, perfection of the interfacial region based on the energy level gradient and lattice matching degree is still a great challenge. Herein, rich vacancies and ultrafine CoSe 2 –FeSe 2 heterojunctions with semicoherent phase boundary are simultaneously obtained, which possess unique electronic structures and abundant active sites. When employed as anodes for potassium‐ion batteries (PIBs), CoSe 2 –FeSe 2 @C composites display a reversible potassium storage of 401.1 mAh g −1 at 100 mA g −1 and even 275 mAh g −1 at 2 A g −1 . Theoretical calculation also reveals that the potassium‐ion diffusion can be dramatically promoted by the controllable CoSe 2 –FeSe 2 heterojunction.