Design Principles for High-Capacity Mn-Based Cation-Disordered Rocksalt Cathodes

Date Published
01/2020
Publication Type
Journal Article
Authors
DOI
10.1016/j.chempr.2019.10.001
Abstract

Mn-based Li-excess cation-disordered rocksalt (DRX) oxyfluorides are promising candidates for next-generation rechargeable battery cathodes owing to their large energy densities, the earth abundance, and low cost of Mn. In this work, we synthesized and electrochemically tested four representative compositions in the Li-Mn-O-F DRX chemical space with various Li and F content. While all compositions achieve higher than 200 mAh g−1 initial capacity and good cyclability, we show that the Li-site distribution plays a more important role than the metal-redox capacity in determining the initial capacity, whereas the metal-redox capacity is more closely related to the cyclability of the materials. We apply these insights and generate a capacity map of the Li-Mn-O-F chemical space, LixMn2-xO2-yFy (1.167 ≤ x ≤ 1.333, 0 ≤ y ≤ 0.667), which predicts both accessible Li capacity and Mn-redox capacity. This map allows the design of compounds that balance high capacity with good cyclability.

Journal
Chem
Volume
6
Year of Publication
2020
Issue
1
Pagination
153 - 168
ISSN Number
24519294
Short Title
Chem
Refereed Designation
Refereed
Organizations
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