Premium
Layered Molybdenum (Oxy) Pyrophosphate (MoO 2 ) 2 P 2 O 7 as a Cathode Material for Sodium‐Ion Batteries
Author(s) -
Deng Wenwen,
Feng Xuyong,
Xiao Yao,
Li Changming
Publication year - 2018
Publication title -
chemelectrochem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.182
H-Index - 59
ISSN - 2196-0216
DOI - 10.1002/celc.201800005
Subject(s) - amorphous solid , cathode , materials science , molybdenum , decomposition , pyrophosphate , electrode , battery (electricity) , ion , sodium , cycling , sodium ion battery , phase (matter) , crystal (programming language) , analytical chemistry (journal) , inorganic chemistry , crystallography , chemistry , electrochemistry , faraday efficiency , metallurgy , enzyme , biochemistry , power (physics) , chromatography , quantum mechanics , physics , organic chemistry , history , archaeology , computer science , programming language
Layer‐structured (MoO 2 ) 2 P 2 O 7 was prepared through the decomposition of MoO 2 HPO 4 and further used as a cathode material for sodium‐ion batteries. Results reveal that the capacity and cycling stability of the (MoO 2 ) 2 P 2 O 7 /Na battery largely depends on the lower cutoff voltage. When cycling between 4.0 ‐1.5 V, (MoO 2 ) 2 P 2 O 7 delivers a capacity of 180 mAh g −1 in the first cycle, but it drops very fast owing to a phase decomposition of the crystal structure to an amorphous one. The cycling stability is still not good when cycling between 4.0 ‐1.7 V. However, when cycling between 4.0 ‐ 2.0 V, the performance can be significantly improved, which delivers 93 mAh g −1 in the first cycle and, after 50 cycles, the capacity can maintain 55 mAh g −1 . This is mainly attributed to the stable crystal structure of the Na‐intercalated (MoO 2 ) 2 P 2 O 7 electrode. Ex situ X‐ray diffraction examination demonstrates that the volume change of the (MoO 2 ) 2 P 2 O 7 electrode during the first charging process is only 1 %.