Abstract:To solve the problems of poor structural stability and cycling performance degradation faced by traditional nickel-based cathode materials in high-energy-density applications, this research has been conducted on improving their comprehensive electrochemical performance through rare earth element composite modification. Rare earth composite nickel-based thin film materials were prepared using high oxygen pressure assisted melting reaction method, and Pt electrodes were constructed using magnetron sputtering technology. The material structure and properties were characterized by X-ray diffraction, electrochemical workstation, and other methods. System regulation of rare earth species (Nd, Sm, Eu), substrate orientation, and hydrogenation process parameters, with a focus on studying the phase structure, resistance characteristics, and electrochemical response laws. The results showed that after hydrogenation treatment, the basic resistance change ratio of NdNiO3/LaAlO3 films with (110) orientation at room temperature reached 15, and the resistance significantly decreased in the low temperature range; The Pt electrode forms a low contact resistivity (2.081 × 10-5 Ω·cm2) with NdNiO3/LaAlO3, effectively ensuring the accuracy of electrical performance testing. Research has confirmed that rare earth elements can significantly enhance the structural stability and electrochemical cycling stability of nickel-based positive electrode materials by regulating the integrity of the material's crystal lattice, optimizing lithium ion transmission channels, and improving the ion diffusion kinetics performance. The research results have clarified the logical process of process optimization and the mechanism of performance improvement for rare earth-modified nickel-based positive electrode materials, providing important experimental support and technical references for the research and industrial application of high-performance and long-life lithium battery positive electrode materials.
