TY - JOUR
T1 - Electrochemical properties of 0.3Li 2MnO 3·0. 7LiNi 0.5Mn 0.5O 2 composite cathode powders prepared by large-scale spray pyrolysis
AU - Hong, Young Jun
AU - Kim, Jung Hyun
AU - Kim, Min Ho
AU - Kang, Yun Chan
N1 - Funding Information:
This study was supported by the Converging Research Center Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology ( 2011-50210 ). This study was also supported by a grant ( M2009010025 ) from the Fundamental R&D Program for Core Technology of Materials funded by the Ministry of Knowledge Economy (MKE) , Republic of Korea. This study was also supported by Seoul R&BD Program ( WR090671 ).
PY - 2012/8
Y1 - 2012/8
N2 - 0.3Li 2MnO 3·0.7LiNi 0.5Mn 0.5O 2 composite cathode powders with a mixed-layer crystal structure comprising Li 2MnO 3 and LiNi 0.5Mn 0.5O 2 phases are prepared by spray pyrolysis. The composition of the cathode powders is found to be Li 1.19Ni 0.39Mn 0.61O 2 by ICP analysis. At a constant current density of 30 mA g -1, the initial discharge capacities of the composite cathode powders post-treated at 700, 750, 800, and 850°C are 177, 202, 215, and 212 mAh g -1, respectively. The discharge capacity of the composite cathode powders post-treated at 800°C decreases from 215 mAh g -1 to 205 mAh g -1 by the 40th cycle, in which the capacity retention is 95%. The first cycle has a low Coulombic efficiency of 75%. However, in the subsequent cycles, the Coulombic efficiency is retained at nearly 100%. The dQ/dV curves show that Mn exists as Mn 4+ in the sample. The Mn 4+ ions in the cathode powders become increasingly active as the cycle number increases and participate in the electrochemical reaction.
AB - 0.3Li 2MnO 3·0.7LiNi 0.5Mn 0.5O 2 composite cathode powders with a mixed-layer crystal structure comprising Li 2MnO 3 and LiNi 0.5Mn 0.5O 2 phases are prepared by spray pyrolysis. The composition of the cathode powders is found to be Li 1.19Ni 0.39Mn 0.61O 2 by ICP analysis. At a constant current density of 30 mA g -1, the initial discharge capacities of the composite cathode powders post-treated at 700, 750, 800, and 850°C are 177, 202, 215, and 212 mAh g -1, respectively. The discharge capacity of the composite cathode powders post-treated at 800°C decreases from 215 mAh g -1 to 205 mAh g -1 by the 40th cycle, in which the capacity retention is 95%. The first cycle has a low Coulombic efficiency of 75%. However, in the subsequent cycles, the Coulombic efficiency is retained at nearly 100%. The dQ/dV curves show that Mn exists as Mn 4+ in the sample. The Mn 4+ ions in the cathode powders become increasingly active as the cycle number increases and participate in the electrochemical reaction.
KW - A. Layered compounds
KW - B. Chemical synthesis
KW - C. Electrochemical measurements
KW - D. Energy storage
UR - http://www.scopus.com/inward/record.url?scp=84861611920&partnerID=8YFLogxK
U2 - 10.1016/j.materresbull.2012.04.008
DO - 10.1016/j.materresbull.2012.04.008
M3 - Article
AN - SCOPUS:84861611920
SN - 0025-5408
VL - 47
SP - 2022
EP - 2026
JO - Materials Research Bulletin
JF - Materials Research Bulletin
IS - 8
ER -