Powering‐On‐Mars Enabled by Ultrahigh Energy and Power Density Li‐CO ₂ Battery

Abstract The aspiration for Mars necessitates the development of higher‐energy/power‐density battery systems to safeguard both planetary missions and terrestrial sustainability efforts. Li‐CO 2 batteries stand out due to their ultrahigh theoretical energy density and the in situ utilization of Martian CO 2 resources. However, the application prospects are constrained by limited reversible capacity and significant concentration polarization. Herein, 3D printing (3DP) technology is employed to fabricate hierarchical porous ultrathick electrodes with dual ion/gas channels, markedly optimizing CO 2 mass transfer and surface reaction kinetics. Surprisingly, it achieves a record‐breaking comprehensive improvement (even over ten‐fold), including rapid charging rates (10 mA cm −2 ), remarkable discharge capability (386.7 mWh cm −2 ), and ultrahigh cyclic capacity (10 mAh cm −2 ). By mimic of the Martian CO 2 flow as external mass transfer assistance, the areal power density can even reach up to 133 mW cm −2 at 100 mA cm −2 . Meanwhile, the 3DP electrode exhibits excellent temperature tolerance (−80 to 180 °C) and can operate for over 200 Martian solar days at ‐80 °C without external heating. A proof‐of‐concept pouch cell with extraordinary energy efficiency (96.4%) proves its potential for multi‐scenario energy storage. This scalable electrode fabrication renders Mars‐capable Li‐CO 2 batteries no longer just a concept.