Parameter sensitivity analysis and cathode structure optimization of a non-aqueous Li-O2 battery model

Non-aqueous Li-O-2 batteries have gained more attention and are promising power sources for next-generation electric vehicles due to their high energy density. In the present study, a comprehensive one-dimensional model is developed to investigate the performance of non-aqueous Li-O-2 batteries. Two different models for insoluble discharge product growth are compared and the tunneling-effect model is in better agreement with the published experimental data. In order to evaluate the effects of various parameters on battery specific capacity in the model, the parameter sensitivity analysis is conducted under different current densities at a cutoff voltage of 2.4 V. The calculated average sensitivities are classified as three levels, including insensitive, sensitive, and very sensitive. The porosity of the cathode is found to be the most sensitive parameter to specific capacity. Based on this, a hierarchical porous cathode structure with gradient initial porosity distribution is proposed according to the distribution of cathode product and effective porosity. Our model shows that the hierarchical cathode structure can improve specific capacity by up to 10.38%.