Improving the Discharge Characteristics of Nonaqueous Lithium-Oxygen Batteries by Constructing Microchannels

Abstract

Non-aqueous lithium-oxygen batteries (NALOBs) are a brand-new variety of recyclable batteries. Its theoretical energy density is very high, and it has enormous potential for use in a variety of industries. However, its cycle performance and discharge capacity still fall short of the scope of its application. Its low performance is mostly a result of the oxygen (O2) transport issues brought on by the cathode microstructure and insoluble discharge products. In response to the challenge of diffusing O2 to the cathode separator side, this work presents a new air cathode structure with microchannels. Experimental testing reveals that electrodes with microchannel structures can enhance specific capacity by around 16.9%, showing the feasibility of this method in enhancing electrode discharge. The material diffusion and discharge processes are simulated using the mesoscale multiphysical field coupling mathematical model using the lattice Boltzmann method after geometric reconstruction of the cathode. According to the study's findings, the construction of microchannels reduces the cathode's diffusion resistance while increasing its O2 concentration during the discharge process. In addition, the study also discusses the influence of the radius, morphology, number, and distribution of microchannels in the electrode on the O2 transport performance in different regions of the electrode.