Innovative Mars battery uses planet’s atmosphere as fuel

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

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

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 373.9Wh 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 maximised the effective reaction area of the Martian atmosphere through integrated electrode preparation and a folded cell structure design. By enlarging the cell size to 4cm2, they further enhanced the energy density of the pouch battery to 76Wh kg-1 and 630Wh 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 volatilisation 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.