The emerging interest in Na+-ion batteries should increase the relative importance of higher voltage positive electrodes as a response to the lower voltage imparted by the Na/Na+ redox reaction relative to that of Li/Li+. The 4.7 V LiMn1.5Ni0.5O4 spinel is already an attractive candidate for high-voltage lithium-ion positive electrodes, and its host structure, -Mn0.75Ni0.25O2, could be of even greater importance for Na batteries. The electrochemical and structural characteristics of higher-voltage NaxMn1.5Ni0.5O4 relative to NaxMn2O4 during ion insertion are investigated for the first time. High-resolution electrochemistry, coupled with in situ and ex situ X-ray diffraction, is utilized to provide initial insights into the mechanism of Na+ insertion. Distinct electrochemical challenges brought forth by Na+ ion insertion into the spinel structure are also discussed in detail.
All Science Journal Classification (ASJC) codes
- Chemical Engineering(all)
- Materials Chemistry