Suppressing the P2 - O2 phase transformation and Na+/vacancy ordering of high-voltage manganese-based P2-type cathode by cationic codoping

Feng Li; Yuhang Tian; Yanyun Sun; Peiyu Hou; Xianqi Wei; Xijin Xu

doi:10.1016/j.jcis.2021.11.171

Suppressing the P2 - O2 phase transformation and Na⁺/vacancy ordering of high-voltage manganese-based P2-type cathode by cationic codoping

J Colloid Interface Sci. 2022 Apr:611:752-759. doi: 10.1016/j.jcis.2021.11.171. Epub 2021 Nov 30.

Authors

Feng Li¹, Yuhang Tian¹, Yanyun Sun², Peiyu Hou³, Xianqi Wei¹, Xijin Xu⁴

Affiliations

¹ School of Physics and Technology, University of Jinan, Jinan, Shandong Province 250022, China.
² School of Automobile and Traffic Engineering, Jiangsu University of Technology, Jiangsu Province 213001, China.
³ School of Physics and Technology, University of Jinan, Jinan, Shandong Province 250022, China. Electronic address: sps_houpy@ujn.edu.cn.
⁴ School of Physics and Technology, University of Jinan, Jinan, Shandong Province 250022, China. Electronic address: sps_xuxj@ujn.edu.cn.

PMID: 34887061
DOI: 10.1016/j.jcis.2021.11.171

Abstract

High-voltage and low-cost manganese-based P2-type oxides show real promise as promising cathode for sodium-ion batteries (SIBs). But the P2 - O2 phase transformation and Na⁺/vacancy ordering results in the inferior structural stability and Na⁺ diffusion coefficient, which further leads to rapid decay of capacity and poor rate capability. Herein, in consideration of the synergetic effects of dual cationic doping, electrochemically inactive Li⁺ and active Co³⁺ codoping are proposed to solve the above issues. The novel two-step doping strategy, Co doping during synthesis of precursors via coprecipitation reaction followed by Li doping during solid-state reaction, are rationally developed. As anticipated, the Li/Co codoped P2-type oxide exhibits the absence of P2 - O2 phase transformation and Na⁺/vacancy disordering, which gives rise to an outstanding cycling stability (86.7% capacity retention within 100 cycles at 0.1C) and high-rate capability (reversible capacity of 109 mAh g^-1 even at 10C). In addition, the full-cells composed of the codoped P2-type positive and hard carbon negative show high energy-density, good lifespan and high-rate property. This proposed cationic codoping provides an effective and scalable tactics for modulating the structural properties of high-voltage P2-type cathodes for advanced SIBs.

Keywords: Cationic codoping; Na(+)/vacancy ordering; P2-type cathode; P2−O2 phase transformation; Sodium-ion batteries.