Thermal plasma synthesis and electrochemical properties of high-voltage LiNi0.5Mn1.5O4 nanoparticles

被引：3

作者：

Sone, Hirotaka ^{[1
]}

Yoshida, Shuhei ^{[1
]}

Tanaka, Manabu ^{[1
]}

Watanabe, Takayuki ^{[1
]}

机构：

[1] Kyushu Univ, Dept Chem Engn, Fukuoka 8190395, Japan

来源：

MATERIALS RESEARCH EXPRESS | 2020年 / 7卷 / 01期

关键词：

thermal plasma; Li-Ni-Mn-oxide nanoparticles; crystal structure; Gibbs free energy; thermodynamics of Li-Ni-Mn-oxide; CATHODE MATERIALS; HOMOGENEOUS NUCLEATION; CAPACITY LOSS; PERFORMANCE; PROGRESS;

D O I：

10.1088/2053-1591/ab5f2e

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

The synthesis of LiNi0.5Mn1.5O4 has been reported to change the crystal structure with the oxygen partial pressure and affect the battery characteristics. LiNi0.5Mn1.5O4 involves the formation of impurities, such as LixNi1-xO, LixMn3-xO4, and Li2CO3, at a high temperature range exceeding 700 degrees C because oxygen loss occurs during synthesis. LiNi0.5Mn1.5O4 electrochemically contains Mn4+, however, Mn3+ is formed because of oxygen deficiency. The Li-Ni-Mn-oxide causes a disproportionation of Mn3+ in an oxygen-deficient state. The synthesized Li-Ni-Mn-oxide nanoparticles at 10,000 K by induction thermal plasma formed spinel-type LiNi0.5Mn1.5O4 (space group Fd3m) of Mn4+. The crystal structure of the cubic-spinel nanoparticles approached a LiNi0.5Mn1.5O4 single phase as the flow rate of O-2 increased from 2.5 to 51 min(-1). The formation of LiNi0.5Mn1.5O4 was shown to be accelerated by increasing the O-2 gas flow rate. The measured current-voltage characteristics of LiNi0.5Mn1.5O4 nanoparticles appeared at around 4.7-4.8 V as the reaction peak of Ni2+/Ni3+ and Ni3+/Ni4+. In contrast, the Mn of the Li-Ni-Mn-oxide nanoparticles synthesized in the oxygen-deficient state was less than trivalent, which caused disproportionation of Mn. The measured current-voltage characteristics showed peak of an oxygen desorption at near 4.6 V. This study investigated the factors affecting the crystal structure formation and electrochemical properties of high-voltage LiNi0.5Mn1.5O4 nanoparticles formed in thermal plasma.

引用

页数：13

共 26 条

[1] Synthesis of Ni2B nanoparticles by RF thermal plasma for fuel cell catalyst [J].