Tris(pentafluorophenyl) borane (TPFPB) is evaluated as an additive for improving electrochemical performance of lithium peroxide (Li2O2)-based electrodes. It is found that TPFPB significantly reduced the charge potential of Li2O2-based electrodes during the first charge process and improved reversible capacity during cycling without adding air (or O-2) to the cell. To confirm the effect of TPFPB on electrolyte decomposition, the surface chemistry of Li2O2-based electrodes cycled in electrolytes with and without TPFPB was investigated. (C) 2012 Elsevier B.V. All rights reserved.