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Dial the Mechanism Switch of VN from Conversion to Intercalation toward Long Cycling Sodium‐Ion Battery
Author(s) -
Wei Shiqiang,
Wang Changda,
Chen Shuangming,
Zhang Pengjun,
Zhu Kefu,
Wu Chuanqiang,
Song Pin,
Wen Wen,
Song Li
Publication year - 2020
Publication title -
advanced energy materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 10.08
H-Index - 220
eISSN - 1614-6840
pISSN - 1614-6832
DOI - 10.1002/aenm.201903712
Subject(s) - materials science , pseudocapacitance , intercalation (chemistry) , vanadium nitride , energy storage , vanadium , cathode , battery (electricity) , chemical engineering , power density , nitride , absorption (acoustics) , nanotechnology , electrode , supercapacitor , inorganic chemistry , layer (electronics) , composite material , power (physics) , thermodynamics , metallurgy , capacitance , electrical engineering , chemistry , physics , engineering
Transition metal nitrides are promising energy storage materials in regard to good metallic conductivity and high theoretical specific capacity, but their cycling stability is impeded by the huge volume change caused by the conversion reaction mechanism. Here, a simple strategy to produce an intercalation pseudocapacitive‐type vanadium nitride (VN) by one‐step ammonification of V 2 C MXene for sodium‐ion batteries is reported. Profiting from a distinctive layered structure pillared by Al atoms in the layer spacing, it delivers a high capacity of 372 mA h g −1 at 50 mA g −1 and a desirable rate performance. More importantly, it shows remarkably long cycling stability over 7500 cycles without capacity attenuation at 500 mA g −1 . As expected, it is found that the intercalation pseudocapacitance plays an important role in the excellent performance, by using in situ X‐ray diffraction and ex situ X‐ray absorption structure characterization. Even more remarkable, are the high energy and power density of the sodium‐ion capacitor after coupling with a carbon‐based cathode. The hybrid device possesses an energy density of 78.43 Wh kg −1 at power density of 260 W kg −1 . The results clearly show that such a unique‐layered VN with outstanding Na storage capability is an excellent new material for energy storage systems.