Analysis of the Discharge\nTermination Mechanism of\na Nonaqueous Li–O<sub>2</sub> Battery Based on a Digital Reconstruction\nModel

The service life of the lithium–oxygen (Li–O<sub>2</sub>) battery is an essential factor in measuring the performance\nof the battery, and it is also imperative to clarify the reason for\nbattery termination. In this work, the positive electrode of a nonaqueous\nLi–O<sub>2</sub> battery was selected after cutoff under different\ndischarge conditions, and the digital reconstruction model of the\npositive electrode was carried out by X-CT technology. The reconstructed\npositive electrode’s structural characteristics, material transport\ncharacteristics, and electrical conductivity were analyzed. It is\nfound that the positive electrode has an apparent expansion phenomenon\nafter constant capacity cyclic charge and discharge, but this situation\nis not evident after deep discharge. After the constant capacity test\nis cut off, the product distribution range in the positive electrode\nis more comprehensive and the material transport efficiency is higher.\nHowever, after deep discharge, the product distribution in the positive\nelectrode is more concentrated and the material transport efficiency\nis lower. There are apparent differences in the termination mechanism\nbetween constant capacity cycle discharge and deep discharge. This\npaper provides a compelling theoretical basis for revealing the discharge\ntermination mechanism of nonaqueous Li–O<sub>2</sub> batteries.