Investigation on the Strategies for Discharge Capacity Improvement of Aprotic Li-CO₂ Batteries

Abstract

Aprotic Li-CO 2 batteries offer a sustainable strategy for large-scale CO 2 fixation and meanwhile providing electricity with high specific energy densities. However, the limited practical capacity hinders the application of this technology. To achieve a high-capacity Li-CO 2 battery, parameter sensitivity analysis based on a developed model is conducted in this work to identify the limiting factors. It is found that the initial porosity of the cathode is the most determining factor to the specific capacity. To this end, various cathode structures including hierarchical, tapered, parabolic, trapezoid, and frustum conical pore distribution modes are designed and evaluated. Among these designs, the frustum conical porous cathode compared to homogeneous one can lead to the largest capacity improvement of over 60%, demonstrating the feasibility of improving the capacity through structure design. Besides, the present sensitivity analysis system is evaluated at high current densities, and the experimental approaches for fabricating the designed cathodes are proposed and detailly elaborated. This work highlights the effective cathode structure design for highperformance aprotic Li-CO 2 batteries.

Revisiting the Role of Discharge Products in Li–CO2 Batteries

“…The battery capacity is closely related to charge/discharge rate, for example, Xiao et al displayed the discharge–voltage curves at various current densities on a CNT‐based cathode and found the full capacity at 0.2 mA cm −2 (4881.03 mAh g −1 ) was 35.2% higher than that at 0.5 mA cm −2 (3611.83 mAh g −1 ). [ 62 ] They identified, based on SEM results, that the DP morphology evolves significantly from small particles to large Li 2 CO 3 crystals with an increase of current density. Therefore, they attributed the capacity discrepancy at various current densities to morphology differences in DPs.…”

Carbon Tube-Based Cathode for Li-CO2 Batteries: A Review

“…The energy efficiency reaches 73.3% without pollution, which is of great significance to the solution of energy and environmental problems (Figure 3). Therefore, it is urgent to carry out proper mechanism research to confirm the reaction process of the system [19,20].…”

A Quantitative Understanding of Electron and Mass Transport Coupling in Lithium–Oxygen Batteries

“…[10,19] The typically continuous medium assumption, where pore properties are replaced by a single parameter, porosity, oversimplifies the impact of pore sizes and connectivity on transport. [10,19,45,46] The hot 3D scanningnumerical reconstruction, although reported for LIBs, [47,48] is uncertain for larger-scale computational tasks in LOBs. The multiphase reactions and unique boundary migration issues would cause a significantly higher computational cost.…”