ChemInform Abstract: Electrochemistry of Manganese Dioxide in Lithium Nonaqueous Cell. Part 1. X‐Ray Diffractional Study on the Reduction of Electrolytic Manganese Dioxide.

Abstract

ChemInform Abstract The XRD data obtained during the electrochemical reduction of heat-treated (250 rc C and 400 rc C, 7 d) electrolytic MnO2 cathodes in a lithium nonaqueous cell indicate that the reaction occurs via electron injection and Li+ insertion to form a LixMnO2 phase without destruction of the core structure. The structural changes occurring during reduction are described in detail assuming a tetragonal sublattice.

Synthesis and Stoichiometric Analysis of a Li-Ion Battery Cathode Material

“…For example, the weighing of the starting materials themselves is a crucial step and if not done carefully can be a serious source of error. Calcination procedures may also produce errors in stoichiometries due to certain processes such as Li vapourization at high temperatures of 850 ˚C and above producing lithium deficient materials (Ohzuku et al 1990). The resulting final product may therefore be slightly different from the calculated values.…”

The Structural Design of Electrode Materials for High Energy Lithium Batteries

“…A Li x Mn 2 O 4 spinel electrode delivers one-half of its capacity at 4 V over the compositional range 0 ≤ x < 1 (Ohzuku et al, 1990;Thackeray et al, 1997), and the other half at ~3 V for 1 ≤ x ≤ 2 (Thackeray et al, 1983). Because there are two manganese ions per spinel formula unit, the 4-V capacity is restricted to 0.5 Li per transition metal ion, like the layered LiMO 2 electrodes (M = Co, Ni) mentioned above in practical cells; the theoretical 4 V capacity of LiMn 2 O 4 is 148 mA·h/g, most of which can be realized in practice.…”

“…With respect to the positive electrode (cathode), the spinel LiMn 2 O 4 (Thackeray et al, 1984a;Ohzuku et al, 1990) and its substituted derivatives , and LiFePO 4 (olivine) (Padhi et al, 1997) have also been commercialized in high-voltage lithium-ion cells. In practice, however, all three materials (LiCoO 2 , LiMn 2 O 4 and LiFePO 4 ) provide a relatively low electrochemical capacity at high potentials (3.5-4 V), thereby limiting the available energy of the lithium-ion cell.…”

A new method of pretreatment of lithium manganese spinels and high-rate electrochemical performance of Li[Li0.033Mn1.967]O4

“…LiMn 2 O 4 belongs to the cubic Fd 3m space group, Z = 8 [4,6]. In this cubic structure, oxygen ions occupy the tetrahedral positions (32e) and form the cubic dense packing.…”