Lifetime of lithium–oxygen battery in “soft” and “hard” cycling modes

Abstract The effect of discharge depth on the life of lithium–oxygen batteries (LOBs) is studied under cycling in TEGDME and DMSO media. It is shown that in LOBs based on alkali–treated carbon nanotubes (CNTOH and PtCo/CNTOH) combining high outer surface area, volume, and average diameter of pores, cycling reversibility increases at a transition from the maximum coverage of the positive electrode by lithium peroxide to the monolayer coverage. For LOBs with XC-72, reversibility does not depend on the discharge depth owing to the close values of the Li2O2 monolayer thickness and average pore size. For each of the materials, replacement of DMSO by TEGDME allows enhancing the LOB life in the studied cycling modes. For CNTOH and PtCo/CNTOH, coefficients are determined that characterize variation of LOB parameters at a transition from the monolayer coverage to the maximum coverage of the positive electrode. The calculated coefficients allow predicting the LOB characteristics at a change in the discharge mode or solvent type.