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

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-yAlXMgyO2 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-yAlXMgyO2 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.(c) 2023 Elsevier Inc. All rights reserved.

Automated summary

Developing Co-free LiNiO2-based layered cathode materials is crucial for meeting the demands of lithium-ion batteries with high energy density, long cycling life, and low cost. In this study, LiNi1-X-yAlXMgyO2 materials were synthesized using a solid-solid interface elemental interdiffusion strategy. The incorporation of Mg2+ and Al3+ ions in different layers of the crystal lattice resulted in improved electrochemical performance, such as cycling stability and rate capability. The in-situ XRD characterization and structural analysis revealed that stabilization of the crystal structure, preservation of the integrity of secondary particles, and enlargement of interlayer spacing contributed to the superior performance of the materials. The Mg/Al co-doping strategy shows promise for designing cobalt-free nickel-rich materials.