Statistical design and mechanism analysis of cement-based composites as cathodes in seawater dissolved oxygen batteries

Efficient utilization of marine resources is pivotal in addressing the growing challenges of energy shortages within marine infrastructure. This study represents the first investigation into the application of cement-based composite materials as cathode electrodes in seawater dissolved oxygen batteries. A six-factor, five-level orthogonal design was employed to systematically explore the synergistic effects of various factors, including carbon materials, catalyst types, water-to-cement ratio, carbon-to-cement ratio, catalyst content, and corrosion inhibitors. The TOPSIS-EWM multi-criteria evaluation method was utilized to identify the optimal formulation from 25 potential combinations, with the top-performing samples being: graphite powder/cement = 0.20, activated carbon/cement = 0.04, w/c = 0.60. The study reveals a complex coupling between the cathode material's microstructure and its macroscopic performance, encompassing electrochemical characteristics, dissolved oxygen adsorption capacity, corrosion resistance, and mechanical strength. These findings provide a solid theoretical foundation and practical engineering solutions for the integration of cement-based cathode materials in marine energy storage systems.