Lithium bis(oxalato) borate (LiBOB) is utilized as an oxidative additive to prevent the unwanted electrolyte decomposition on the surface of Li1.17Ni0.17Mn0.5Co0.17O2 cathodes. Our investigation reveals that the LiBOB additive forms a protective layer on the cathode surface and effectively mitigates severe oxidative decomposition of LiPF6-based electrolytes. Noticeable improvements in the cycling stability and rate capability of Li1.17Ni0.17Mn0.5Co0.17O2 cathodes are achieved in the LiBOB-added electrolyte. After 100 cycles at 60 degrees C, the discharge capacity retention of the Li1.17Ni0.17Mn0.5Co0.17O2 cathode was 28.6% in the reference electrolyte, whereas the LiBOB-containing electrolyte maintained 77.6% of its initial discharge capacity. Moreover, the Li1.17Ni0.17Mn0.5Co0.17O2 cathode with LiBOB additive delivered a superior discharge capacity of 115 mAh g(-1) at a high rate of 2 C compared with the reference electrolyte. The OCV of a full cell charged in the reference electrolyte drastically decreased from 4.22 V to 3.52 V during storage at 60 degrees C, whereas a full cell charged in the LiBOB-added electrolyte exhibited superior retention of the OCV. (C) The Author(s) 2014. Published by ECS. All rights reserved.