Research into cobalt-free positive electrode materials for lithium-ion batteries was published in ACS Applied Materials & Interfaces.

Cobalt has been used in positive electrode materials since it enables the batteries to have low resistance and long life. However, efforts are being made to eliminate the use of cobalt to help alleviate pressure on global resources. There is strong demand for cobalt-free positive electrode materials to help realize a safer and more secure society. This paper describes high-capacity positive electrode materials consisting of manganese, which is one of the most abundant elements in the Earth’s crust. Prolonging cycling-life was realized by introducing fluorine to the materials. Synchrotron-beam analysis was applied to examine the micro- and macroscopic structural changes of the materials during charge and discharge, and revealed that fluorine introduction can maintain crystal structures, including local structures, after charge and discharge. This has the potential to enable the development of lithium-ion batteries with a high energy density and long cycling life, and may also help to reduce the material supply chain risk.

Title: How Fluorine Introduction Solves the Spinel Transition, a Fundamental Problem of Mn-based Positive Electrodes
Authors:Mahara, Y., Nagasako, N., Oka, H., Kondo, Y., Kosaka, S., Nakano, H., Nonaka, T., Makimura, Y.
Journal Name: ACS Applied Materials & Interfaces
Published: 17 May 2022
https://doi.org/10.1021/acsami.2c02868