A Universal Strategy toward the Precise Regulation of Initial Coulombic Efficiency of Li-Rich Mn-Based Cathode Materials

Weibin Guo; Chenying Zhang; Yinggan Zhang; Liang Lin; Wei He; Qingshui Xie; Baisheng Sa; Laisen Wang; Dong-Liang Peng

doi:10.1002/adma.202103173

A Universal Strategy toward the Precise Regulation of Initial Coulombic Efficiency of Li-Rich Mn-Based Cathode Materials

Adv Mater. 2021 Sep;33(38):e2103173. doi: 10.1002/adma.202103173. Epub 2021 Aug 1.

Authors

Weibin Guo¹, Chenying Zhang¹, Yinggan Zhang¹, Liang Lin¹, Wei He¹, Qingshui Xie¹, Baisheng Sa², Laisen Wang¹, Dong-Liang Peng¹

Affiliations

¹ State Key Laboratory of Physical Chemistry of Solid Surface Fujian Key Laboratory of Materials Genome Collaborative Innovation Center of Chemistry for Energy Materials College of Materials, Xiamen University, Xiamen, 361005, China.
² Multiscale Computational Materials Facility College of Materials Science and Engineering, Fuzhou University, Fuzhou, 350100, China.

PMID: 34337804
DOI: 10.1002/adma.202103173

Abstract

Li-rich Mn-based cathode materials (LRMs) are potential cathode materials for high energy density lithium-ion batteries. However, low initial Coulombic efficiency (ICE) severely hinders the commercialization of LRM. Herein, a facile oleic acid-assisted interface engineering is put forward to precisely control the ICE, enhance reversible capacity and rate performance of LRM effectively. As a result, the ICE of LRM can be precisely adjusted from 84.1% to 100.7%, and a very high specific capacity of 330 mAh g^-1 at 0.1 C, as well as outstanding rate capability with a fascinating specific capacity of 250 mAh g^-1 at 5 C, are harvested. Theoretical calculations reveal that the introduced cation/anion double defects can reduce the diffusion barrier of Li⁺ ions, and in situ surface reconstruction layer can induce a self-built-in electric field to stabilize the surface lattice oxygen. Moreover, this facile interface engineering is universal and can enhance the ICEs of other kinds of LRM effectively. This work provides a valuable new idea for improving the comprehensive electrochemical performance of LRM through multistrategy collaborative interface engineering technology.

Keywords: Li-rich Mn-based cathode materials; built-in electric field; cation/anion double defects; in situ surface reconstruction; initial Coulombic efficiency.

Abstract

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