Cobalt-free nickel-rich cathode materials based on Al/Mg co-doping of LiNiO2 for lithium ion battery

Lina Shen; Fanghui Du; Qun Zhou; Tao Xu; Zhongxu Fan; Yali Wen; Jie Wang; Juan Wu; Junwei Zheng

doi:10.1016/j.jcis.2023.01.134

Cobalt-free nickel-rich cathode materials based on Al/Mg co-doping of LiNiO₂ for lithium ion battery

J Colloid Interface Sci. 2023 May 15:638:281-290. doi: 10.1016/j.jcis.2023.01.134. Epub 2023 Feb 1.

Authors

Lina Shen¹, Fanghui Du², Qun Zhou³, Tao Xu¹, Zhongxu Fan¹, Yali Wen¹, Jie Wang¹, Juan Wu¹, Junwei Zheng⁴

Affiliations

¹ College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, China.
² Shandong Key Laboratory of Chemical Energy Storage and New Battery Technology, School of Chemistry and Chemical Engineering, Liaocheng University, Liaocheng 252059, China.
³ College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, China. Electronic address: zhq@suda.edu.cn.
⁴ College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, China. Electronic address: jwzheng@suda.edu.cn.

PMID: 36739746
DOI: 10.1016/j.jcis.2023.01.134

Abstract

To develop Co-free LiNiO₂-based layered cathode materials is crucial for meeting the demands of the lithium-ion batteries with high energy density, long cycling life, and low cost. Herein, the LiNi₁_-x-yAl_xMg_yO₂ materials are synthesized by the solid-solid interface elemental interdiffusion strategy. It is elucidated that the Mg²⁺ and Al³⁺ ions are mainly doped in the Li slabs and transition metal slabs, respectively, leading to the alteration of the crystal lattice. Furthermore, the incorporation of the Mg²⁺ ions may induce more Ni²⁺ ions formed in the transition metal slabs, which would have great impact on the electrochemical performance of the materials. The LiNi₁_-x-yAl_xMg_yO₂ materials with optimized Mg/Al co-doping exhibit much better electrochemical performance than the pristine LiNiO₂ and Al-doped LiNiO₂ materials, including cycling stability and rate capability. The in-situ XRD characterization and structural analysis show that stabilization of the crystal structure, preservation of the integrity of the secondary particles, and enlargement of the interlayer spacing by the Mg/Al co-doping are the main factors responsible for the superior performance of the materials. The Mg/Al co-doping strategy might be the promising approach for the design of the cobalt-free nickel-rich materials.

Keywords: Al/Mg co-doping; Crystal structure; High-nickel layered oxides; Microcracks; Phase transition; Sol-gel.