Fabricating Heterostructures for Boosting the Structure Stability of Li-Rich Cathodes

Yao Li; Qing Zhao; Mengke Zhang; Lang Qiu; Zhuo Zheng; Yang Liu; Yan Sun; Benhe Zhong; Yang Song; Xiaodong Guo

doi:10.1021/acsomega.2c07313

Fabricating Heterostructures for Boosting the Structure Stability of Li-Rich Cathodes

ACS Omega. 2023 Feb 13;8(7):6720-6728. doi: 10.1021/acsomega.2c07313. eCollection 2023 Feb 21.

Authors

Yao Li¹, Qing Zhao¹, Mengke Zhang¹, Lang Qiu¹, Zhuo Zheng², Yang Liu³, Yan Sun⁴, Benhe Zhong¹, Yang Song¹, Xiaodong Guo¹

Affiliations

¹ College of Chemical Engineering, Sichuan University, Chengdu 610065, Sichuan, China.
² The State Key Laboratory of Polymer Materials Engineering, Polymer Research Institute of Sichuan University, Chengdu 610065, Sichuan, China.
³ School of Materials Science and Engineering, Henan Normal University, Xinxiang 453007, Henan, China.
⁴ School of Mechanical Engineering, Chengdu University, Chengdu 610106, Sichuan, China.

Abstract

Li-rich Mn-based oxides are regarded as the most promising new-generation cathode materials, but their practical application is greatly hindered by structure collapse and capacity degradation. Herein, a rock salt phase is epitaxially constructed on the surface of Li-rich Mn-based cathodes through Mo doping to improve their structural stability. The heterogeneous structure composed of a rock salt phase and layered phase is induced by Mo⁶⁺ enriched on the particle surface, and the strong Mo-O bonding can enhance the TM-O covalence. Therefore, it can stabilize lattice oxygen and inhibit the side reaction of the interface and structural phase transition. The discharge capacity of 2% Mo-doped samples (Mo 2%) displays 279.67 mA h g^-1 at 0.1 C (vs 254.39 mA h g^-1 (pristine)), and the discharge capacity retention rate of Mo 2% is 79.4% after 300 cycles at 5 C (vs 47.6% (pristine)).