Electrochemical characterization of a new high capacity cathode

Abstract

This paper reports on the electrochemistry of a new series of layered manganese oxide cathodes for lithium-ion cells. The layered structure is stabilized by the partial substitution of the manganese by chromium and lithium atoms and by the partial or complete oxidation of the manganese to the 4 oxidation state. The series covers the range of compositions Li x Cr y Mn 2Ày O 4z for which 2:2 < x < 4, 0 < y < 2 and z ! 0.

Direct evidence of oxygen evolution from Li1+x (Ni1/3Mn1/3Co1/3)1−x O2 at high potentials

“…Two representative NMC compounds with nominal values of overlithiation degree x = 0 and x = 0.1 were therefore synthesized and compared. We confirmed the differences between the two compounds in the charge/ discharge curves at high potentials, as reported in the literature [7][8][9][10][11]. The high voltage region was then examined for both NMC compounds with Differential Electrochemical Mass Spectrometry (DEMS), an on-line analytic method detecting gaseous and volatile reaction products.…”

Lithium ion cells using a new high capacity cathode

“…Li x Cr y Mn 2Ày O 4z samples for this study were prepared by a procedure described in a previous work [1]. These samples were cast into electrode sheets by a doctor blade technique and tested in coin cells.…”

“…For cathodes based on ®rst row transition metal oxides, this typically requires a layered oxide structure that remains intact during cycling. Recently, we have succeeded in preparing a series of new cathode materials displaying competitive capacities with reasonably good cycling stability at moderate current densities [1]. These materials appear to be possible alternatives to LiCoO 2 , LiMn 2 O 4 and LiNi 0.8 Co 0.2 O 2 for lithium ion cell cathodes.…”

A comparative study of the thermal stability of Li1−xCoO2 and Li3−xCrMnO5 in the presence of 1 M LiPF6 in 3:7 EC/DEC electrolyte using accelerating rate calorimetry

“…This paper reports on the results obtained from a comparative accelerating rate calorimetry study on a proposed alternative cathode material, Li 3 CrMnO 5 [1] versus the current most commonly used material, LiCoO 2 . The experimental procedures for using accelerating rate calorimetry for the analysis of the thermal stability of lithium ion battery materials were developed by researchers at MoliEnergy Ltd. (1990) [2] and later refined for smaller samples by Richard and Dahn [3].…”