Study on performance of hybrid lithium-air batteries with different alkaline cation pairs in ambient environment

Abstract

Hybrid lithium-air batteries (HLABs) effectively solve the bottleneck problem of discharge product Li2O2 blocking non-aqueous lithium-air batteries' electrode pores, attracting extensive attention. This paper analyzes the battery's cycle performance, deep discharge performance, and main failure reasons in an ambient environment using the LiOH and KOH aqueous solutions as cathode electrolytes. Meanwhile, the authors intensely study the internal mechanism of mass transfer by molecular dynamics simulation method based on these two cases of electrolytes. The KOH aqueous solution as cathode electrolytes of HLABs has superior deep discharge performance due to the better diffusion ability of K+, and the hydration of cations weakened. However, because the KOH is more alkaline than LiOH, the corrosion on LAGP plates will be severe, affecting the battery's cycle performance. So, the cycle discharge performance of the LiOH aqueous solution as cathode electrolytes of HLABs is significantly better than that of the KOH solution. Under the external electric field, the hydration of cations weakened, which is more favorable to the mass transfer of batteries. Therefore, the HLABs with KOH perform better in deep discharge, and the HLABs with LiOH perform better in long cycles. The research results provide a particular reference for subsequent research and application.