Mars presents a highly complex natural environment, characterized by a variety of gas components—95.32% carbon dioxide, 2.7% nitrogen, 1.6% argon, 0.13% oxygen, and 0.08% carbon monoxide—as well as extreme temperature fluctuations, with day-to-night temperature differences of about 60 °C.

To address these challenges, Prof. Peng Tan and Dr. Xu Xiao have developed a novel Mars battery that uniquely utilizes the Martian atmosphere as fuel during discharge. This approach significantly reduces the battery's weight, making it more suitable for space missions.

Their study, "A high-energy-density and long-cycling-lifespan Mars battery," is published in the journal Science Bulletin.

Once depleted, the battery can be recharged using solar energy harvested from the Martian surface, enabling it to be prepared for subsequent discharges. Furthermore, the team simulated Martian surface conditions, including temperature fluctuations, to develop a Mars battery system capable of continuous power output.

The researchers also demonstrate that at a low temperature of 0 °C, the battery achieves an energy density of up to 373.9 Wh kg^-1 and a charge/discharge cycle life of 1,375 hours, which corresponds to approximately two Martian months of continuous operation.

The battery's charge and discharge processes involve the formation and decomposition of lithium carbonate, while trace amounts of oxygen and carbon monoxide in the Martian atmosphere act as reaction catalysts, significantly accelerating the carbon dioxide conversion kinetics.

The team maximized the effective reaction area of the Martian atmosphere through integrated electrode preparation and a folded cell structure design. By enlarging the cell size to 4 cm², they further enhanced the energy density of the pouch battery to 765 Wh kg^-1 and 630 Wh l^-1.

According to the researchers, this study offers a critical proof-of-concept for the application of Mars batteries in real Martian environments.

They aim to advance the development of solid-state Mars batteries in future research, addressing the challenges of electrolyte volatilization under low pressure, and supporting thermal and barometric management systems. This work lays a foundational step toward the development of multi-energy complementary systems for future space exploration.

More information: Xu Xiao et al, A high-energy-density and long-cycling-lifespan Mars battery, Science Bulletin (2024). DOI: 10.1016/j.scib.2024.06.033