Antisite defects, disorder between Li and other cations, are often observed in Li storage compounds synthesized at elevated temperature. In battery materials that have distinct one-dimensional (1-D) Li diffusion channels, preventing antisite formation is considered a good way to obtain desirable electrochemical properties by avoiding channel blockage, which can significantly disrupt Li transport. Thus, it is of critical importance to understand how the antisite modulates the overall Li kinetics in cathode materials. In this work, we investigate lithium manganese borate (LiMnBO 3 ) as a model system in which Li diffuses along the c -axis of its monoclinic lattice. Although it has high theoretical capacity of 222 mAh/g, antisite defects limit the achievable capacity to half of its theoretical value. Our approach to address this limitation is to partially substitute Mn with Fe, which not only leads to immediate improvement in electrochemical properties but also increases the antisite defect concentration. By using ab initio computation and analyzing experimental results, we find that different antisite configurations can affect Li intercalation in different ways and, counter to intuition, channel blockage by the antisite defects is not always detrimental in 1-D materials. At certain conditions, Li migration occurs by channel crossover to detour the channel-blocking defect, and the basic diffusion mechanism is modified from 1-D to 3-D conduction, thereby improving kinetics. This is a refreshing perspective on antisite issues in the 1-D materials. Our model may provide hints to understand and enhance the electrochemical performance of other 1-D materials that suffer from kinetic limitations due to antisite defect through engineering of defect chemistry.
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