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Synergy of Nyquist and Bode Electrochemical Impedance Spectroscopy Studies to Assess the Effect of Morphology on the Electrochemical Properties of Li‐Ni‐Mn‐Al‐O Materials
Author(s) -
Lin Hongxu,
Liang Chenghao,
Liu Chaojun,
Dai Changsong,
Xiong Yueping
Publication year - 2017
Publication title -
chemistryselect
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.437
H-Index - 34
ISSN - 2365-6549
DOI - 10.1002/slct.201700936
Subject(s) - nyquist plot , materials science , bode plot , dielectric spectroscopy , electrochemistry , current density , specific surface area , scanning electron microscope , cathode , analytical chemistry (journal) , chemical engineering , morphology (biology) , nanotechnology , composite material , electrode , chemistry , chromatography , physics , electrical engineering , organic chemistry , transfer function , quantum mechanics , engineering , catalysis , biology , genetics
The agglomerated and sheet Li 1.2 Ni 0.3 Mn 0.6 Al 0.1 O 2.2 materials were synthesized by hydrothermal method (HT‐NMA) and sol‐gel method (SG‐NMA) respectively. Compared with sheet particles, agglomerated particles had better mutual contact. The specific surface area calculated by Brunauer–Emmett–Teller (BET) method was 8.92 m 2 /g for HT‐NMA and 5.90 m 2 /g for SG‐NMA. Larger specific surface area achieved better connections between cathode material and conductive agent. Better electron transitivity contributed to better electrochemical performance of HT‐NMA, at the potential range of 2.0 V–4.8 V, the retention of capacity was 86 % at the current density of 20 mA/g after 31 cycles and the discharge capacity was 108mAh/g at the current density of 1000 mA/g. Both Nyquist and Bode plots were used to deeply investigate the reason for better performance of HT‐NMA, the results showed that agglomerated particles had better electron migration capacity both before and after cycle.