In this study, a new class of contenders for high-voltage and high-capacity positive electrode materials with the composition NaxLi0.7-xNi1-yMnyO2 (0.03 < x ≤ 0.25, 0.5 ≤ y ≤ 0.8) was synthesized by thermal treatment; these positive electrode materials synthesized by Na+/Li+ exchange using P3-Na0.7Ni1-yMnyO2 (0.5 ≤ y ≤ 0.8) as the precursor exhibited a mixture of layered and spinel structures. The (dis)charge voltage-capacity curve of materials with these compositions significantly varied according to the residual Na and Mn content. Notably, HT-NaxLi0.7-xNi1-yMnyO2 (x = 0.093, y = 0.67) exhibited a maximum discharge capacity of 261 mA h g-1 at an average voltage of 3.36 V at 25°C (between 2.0 and 4.8 V), which translates to an energy density of 943 W h kg-1. The obtained electrochemical performance is rationalized by the phase fractions of layered and spinel structures, which is triggered by the residual Na and Mn content in NaxLi0.7-xNi1-yMnyO2.
All Science Journal Classification (ASJC) codes
- Renewable Energy, Sustainability and the Environment
- Energy Engineering and Power Technology
- Physical and Theoretical Chemistry
- Electrical and Electronic Engineering