Oxygen release from high-energy xLi2MnO3·(1−x)LiMO2 (M=Mn, Ni, Co): Electrochemical, differential electrochemical mass spectrometric, in situ pressure, and in situ temperature characterization

• Published in: Electrochimica acta Vol. 93; pp. 114 - 119
• Main Authors: Lanz, Patrick, Sommer, Heino, Schulz-Dobrick, Martin, Novák, Petr
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 30.03.2013
• Subjects: Differential electrochemical mass spectrometry; In situ pressure and temperature measurement; Li-ion batteries; NCM positive electrode material; Oxygen release; Oxygen release; Differential electrochemical mass spectrometry; Li-ion batteries; In situ pressure and temperature measurement; NCM positive electrode material
• ISSN: 0013-4686; 1873-3859
• DOI: 10.1016/j.electacta.2013.01.105

As a positive electrode material for Li-ion batteries, xLi2MnO3·(1−x)LiMO2 (M=Mn, Ni, Co) boasts various advantages compared to LiCoO2, such as higher specific charge (∼250Ah/kg) and lower cobalt content. However, the oxygen release reaction at ∼4.5V vs. Li+/Li is not fully understood. xLi2MnO3·(1−x)LiMO2 has been characterized by a combination of complementary methods, including electrochemical cycling at different temperatures, differential electrochemical mass spectrometry (DEMS), in situ pressure measurement, and in situ temperature measurement. The reaction at ∼4.5V vs. Li+/Li leads to the exothermic release of oxygen and a significant pressure build-up in the cell. Despite this, the electrochemical performance of the material is very promising. Finally, it is shown that the cells should be operated close to room temperature.