Experimental Measurement and Quantification of the Local Cell Reaction in Blended Lithium Insertion Electrodes

Abstract Blended electrodes in which two types of active materials are mixed exhibit synergetic effects due to the interplay between different active materials. Although a local cell reaction within the electrode plays an important role in the blended electrodes, its nature is not yet known because of difficulties associated with experimental measurements. In this study, we developed a method for measuring the local cell reaction using a blended electrode containing a mixture of Li[Ni 1/2 Mn 3/2 ]O 4 and Li[Li 0.1 Al 0.1 Mn 1.8 ]O 4 . The rate of the local cell reaction was successfully quantified using the change in the open‐circuit potential after high‐current discharge. The current for the local cell reaction ( I LCR ) decreased in inverse proportion to the relaxation time after current interruption. I LCR could be formulated using t 0 , a parameter representing the time at which the local cell reaction started, and α , a coefficient representing the rate of the local cell reaction.