Structures, electrochemical properties, and phase evolution behaviors of LiNi1-xMnxO2-δ (0 ≤ x ≤ 1/2) as cathode materials for secondary lithium batteries

Jeong A. Gu, Su An Choi, Yong Joong Lee, Hyun Chul Choi, Yeon Uk Jeong

Research output: Contribution to journalArticlepeer-review

3 Scopus citations

Abstract

In an attempt to get Co-free layered materials for cathode of secondary lithium batteries, LiNi1-xMnxO2-δ (0 ≤ x ≤ 1/2) samples were synthesized by co-precipitation reactions followed by heating in an O2 atmosphere. The optimum heating temperature to get a single-phase hexagonal layered structure increased with Mn contents in the compound. Oxygen vacancies could be gradually reduced with Mn-substitutions. While the lattice constants, M-O distance, and MO2 slab thickness increased with Mn contents, Li-O and inter-slab distances decreased. Electrical conductivities decreased with Mn contents because of the decreased carrier mobility that resulted from smaller primary particle sizes as well as lager amounts of cation mixing. Samples of x = 1/12 and 1/9 in LiNi1-xMnxO2-δ exhibited 0.1 C-rate discharge capacities of 216.2 and 208.9 mAh g−1 and first cycle efficiencies of 93.3 and 94.0%, respectively. The sample of x = 1/9 in LiNi1-xMnxO2-δ exhibited the highest rate capability. From the systematically investigated phase evolution behaviors, a higher activation energy as well as a slower rate of phase transition reaction for higher Mn contents phase were observed.

Original languageEnglish
Pages (from-to)A1280-A1285
JournalJournal of the Electrochemical Society
Volume163
Issue number7
DOIs
StatePublished - 2016

Fingerprint

Dive into the research topics of 'Structures, electrochemical properties, and phase evolution behaviors of LiNi1-xMnxO2-δ (0 ≤ x ≤ 1/2) as cathode materials for secondary lithium batteries'. Together they form a unique fingerprint.

Cite this