The influence of blending LiMn2O4 spinel with LiNi0.8Co0.15Al0.05O2 (NCA) onto the electrochemical and thermal behaviors of the resulting blend electrodes was investigated. The results indicate that NCA addition has a beneficial effect on the discharge capacity of the blends, and thus on the energy density, but in the same time increases the irreversible capacity loss in the first cycle. Also, it deteriorates the rate capability. DSC/TG measurements showed that heat generation for blends containing 50 wt% NCA or less is significantly lower than in the case of pure NCA. Mn dissolution from spinel was considerably reduced by the addition of NCA. Among all investigated blends, the one with 33.3 wt% NCA showed the best behavior in all tested matters. (C) 2011 The Electrochemical Society. [DOI: 10.1149/1.3560582] All rights reserved.