The Sintering Temperature Effect on Electrochemical Properties of LiMn₂O₄

Abstract

The effect of sintering temperature on the electrochemical property of LiMn2O4 was investigated. Results showed that the particle size was increased at higher sintering temperatures while the initial capacity was decreased after high temperature sintering. Capacity fading, on the other hand, was suppressed at lower sintering temperatures since the sintering at higher temperatures (≥ 800 o C) increased the Mn ions with a lower oxidation state (Mn +3 ), which induced structural instability during cycling due to dissolution of Mn ions into the electrolyte. In particular, LiMn2O4 sintered above 830 o C showed severe capacity fading (capacity loss was 38% of initial capacity) by lower coulombic efficiency due to the abnormally increased particle size.

Evolution of Solid Electrolyte Interphase during Cycling and Its Effect on Electrochemical Properties of LiMn2O4

“…3), which is consistent to the voltage plateaus reported by other researchers. 3,6,7 Coulombic efficiency at the initial cycle was relatively low (72%) and it rapidly increased at the 2 nd cycle, and stabilized to 98-99% after the 20 th cycle. On the other hand, the capacity retention decreased drastically to 88% during the early 10 cycles and it was maintained at approximately 81∼84% after 20 th cycle.…”

“…Cycling tests were performed with a VMP3 (Bio-Logic) with a current density of 50 μA/cm 2 over a voltage range of 3.5-4.5 V. After the cycling tests, the electrodes were rinsed using DMC and dried at room temperature in an argon-filled glove box to remove residual LiPF 6 on the electrode surface before subsequent AFM analysis. 3 An AFM (XE-100, Park Systems) was used for SEI analysis before and after the cycling test. AFM measurements were carried out with a cantilever with a stiffness of 42 nN/nm.…”

“…In particular, much interest has been given to the study of SEI formation on LiMn 2 O 4 particles, as its SEI is relatively unstable and ineffective in protecting the electrode surface from side reactions with a protic electrolyte, causing capacity fading due to Mn 2+ ion dissolution. [3][4][5] Although LiMn 2 O 4 has been considered as a promising cathode material for lithium ion secondary batteries due to its stability and high discharge voltage, as well as its non-toxicity and low cost, its capacity fading is known to be a part of the reason for its limited commercial application. Many researchers have studied the effect of SEI on electrochemical properties; however, the transient nature of SEI formed during cycling, and their nanoscale dimension made detailed analyses difficult.…”

Physico-Chemical Properties of LiM0.10Mn1.90O4 (M: Co, Ni, Cr) for Potential Cathode Materials

“…For cathode materials studied, LiMn2O4 spinel was considered as a good cathode due to the higher capacity, cycleability and environmentally friendly [3,4]. However, LiMn2O4 electrodes suffers from rapid capacity fade redox during cycling [5,6]. To minimize the capacity fade, replacing Mn 3+ ions by other transition metal ions such as Co, Ni and Cr is one way [7,8].…”