Electrochemistry of Metal-CO2 Batteries: Principles and Applications

Overuse of non-renewable energy sources has raised fears about an energy deficit throughout the world. In addition, the burning of fossil fuels releases large quantities of greenhouse gases (mainly carbon dioxide (CO2)) leading to serious environmental problems, particularly global warming. Metal-carbon dioxide batteries, which can capture and resourcefully utilize CO2, are of great research significance. This article explores the importance of developing Metal-CO2 batteries and their positive impact on the environment by introducing three Metal-CO2 batteries. By describing the advantages that Metal-CO2 batteries can offer in two locations, Earth and Mars, this article explores the prospects for their application in energy storage and transportation power. Among the three kinds of Metal-CO2 batteries mentioned in this paper, Li-CO2 batteries have high theoretical specific capacity, but the residual discharge product Li2CO3 will increase the polarization of the batteries by blocking the transport channels, which limits the cycle efficiency of the batteries. Na-CO2 batteries perform electrochemically better than Li-CO2 batteries, but the raw material Na is mainly prepared by electrolysis of molten sodium chloride or sodium hydroxide, which causes large energy consumption and environmental pollution. The raw material of Al-CO2 battery is cheap and easy to obtain, but the specific power of the battery is low. All three types of batteries have the common problems of unclear reaction mechanisms and low charging and discharging efficiencies, and each faces different challenges that need to be investigated. This paper provides ideas for further research on Metal-CO2 batteries, and we hope that Metal-CO2 batteries can be really put into use in the future to alleviate the energy shortage and greenhouse effect to a certain extent.