SYNTHESIS AND ELECTROCHEMICAL CHARACTERIZATION OF P2-NA2/3NI1/3MN2/3O2 CATHODE MATERIALS FOR NA-ION BATTERY

Abstract

The P2-type Na2/3Ni1/3Mn2/3O2 cathode material exhibits significant potential for Na-ion batteries due to its favourable qualities, including high energy density, significant volumetric capacity, superior sodium ion conductivity, ease of synthesis, and favourable air stability. It provides a 173 mAh/g theoretical specific capacity, subject to charge compensation for Ni2+, Ni3+, and Ni4+. High voltage operation improves energy density and specific capacity, making it useful for real-world applications. On the other hand, this also causes a negative P2-O2 phase transition, which has a substantial impact on sodium ion diffusion kinetics and cycle stability. Furthermore, during cycling, Na+/vacancy ordering transitions cause significant capacity decay and poor reversibility. The most recent developments on Na2/3Ni1/3Mn2/3O2 are presented in this project, with an emphasis on methods to strengthen its structural integrity and enhance its electrochemical characteristics. Based on the state and advancement of current research, practical difficulties, and challenges are also put out.