Self-Standing Porous Carbon Electrodes with Lean Electrolyte and High Areal Capacity Conditions for Rechargeable Lithium–Oxygen Batteries

Abstract

Rechargeable lithium–oxygen batteries (LOBs) have the highest theoretical energy densities of all the lithium-based batteries; however, the key challenges facing them are excessing electrolyte amounts and operating at low areal capacity conditions. Thus far, few studies have investigated the performance of the LOBs under practical conditions using appropriate technological parameters. In this study, we prepared a series of carbon-black based self-standing membranes with different pore structures. The self-standing carbon membranes, which were prepared by applying a non-solvent-induced phase separation (NIPS) technique have investigated the relationship between the physicochemical properties and battery performance at low electrolyte/areal capacity ratio (E/C < 10 g/Ah) condition. As a result, the discharge capacity exhibits a clear correlation with the physicochemical property. On the other hand, the cycle number of the LOBs did not simply correlate with the total discharge capacity of the self-standing carbon electrodes. Interestingly, it is observed that the self-standing electrode mainly composed of a unique mesoporous structure exhibits superior cycle performance under small E/C conditions (E/C < 5 g/Ah). Therefore, a turbostratic morphology with a three-dimensional hexagonal array of the unique mesoporous structure is beneficial for exhibiting superior LOB performance under lean electrolyte condition (Figure 1). We believe that the results obtained in the present study give an insight into the development of a new direction for the material design of porous carbon electrodes for achieving a high LOB performance and long cycle life of practical significance. Figure 1