Probing the electrochemical evolutions of Na–CO2 nanobatteries on Pt@NCNT cathodes using in-situ environmental TEM

Na–CO2 batteries possess many virtues including low cost, abundant sodium-containing resources, and environment-friendly nature. Understanding the electrochemical reaction processes is fundamental for battery design and performance enhancement of Na–CO2 batteries. Using in-situ environmental transmission electron microscopy in CO2 gas, we directly probed the morphology evolution and phase transformations of the charge and discharge products with single Pt atom and nitride doped carbon nanotube ([email protected]) cathode in a Na–CO2 nanobattery. The discharge reaction produces Na2CO3 and carbon, which subsequently decomposed into Na ions and CO2 during charge. The discharge rate was boosted with the help of the single-atom Pt catalyst. Our work provides a fundamental insight into the governing principles on Na–CO2 battery design for better energy storage devices.