Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7744352 | Solid State Ionics | 2018 | 5 Pages |
Abstract
High-voltage cathode LiMn1.5Ni0.5O4 particles with average size of approximately 2â¯Î¼m were prepared using a two-step process. Low-temperature magnetic measurements indicated them as ferrimagnetic materials with high Neel temperature (146.5â¯K) and high magnetization (107â¯emu/g at 4.5â¯K) that closely approximates the theoretical value of the stoichiometric LiMn1.5Ni0.5O4 compound. Because of their high-purity and high crystallinity, their redox signals were observed only around 4.7â¯V. Their low-rate capacity was sufficiently high (about 140â¯mAh/g at 0.1â¯C). Their capacity retention after the 100th cycle was higher than 95%. In spite of the low specific surface area of the LiMn1.5Ni0.5O4 particles, they exhibited high reversible capacity even at a high-current rate. Additionally, the in-situ X-ray diffraction was conducted to elucidate the reaction process, which indicated that the electrochemical reaction progresses reversibly with two consecutive two-phase reactions. The lattice parameters of three corresponding phases remained almost unchanged on the reactions (0.8165, 0.8087, and 0.8000â¯nm). The presence of the intermediate phase might give the relaxation of the structural variation during the electrochemical reaction.
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Physical Sciences and Engineering
Chemistry
Electrochemistry
Authors
T. Nakamura, M. Tabuchi, T. Konya, Y. Shiramata, Y. Kobayashi,