Abstract
Lithium (Li)-CO(2) batteries, capable of converting CO(2) to Li(2)CO(3)/C while delivering significant energy, have attracted extensive research interest. However, their feasibility remains controversial and underexplored. To address this, a rigorous testing system combining ECC-air battery models and differential electrochemical mass spectrometry (DEMS) was developed to ensure a pure gas environment. Findings reveal that even minute O(2) permeation (0.5%) from air can elevate the discharge plateau, misleadingly transforming Li-CO(2) into Li-O(2)/CO(2) batteries. Under strict testing, true Li-CO(2) battery performance falls short of reported successes. Experimental and theoretical confirmation shows the 4Li + 3CO(2) → 2Li(2)CO(3) + C reaction proceeds at a lower discharge plateau (<2.0 V), a voltage window traditionally overlooked. This work underscores the need for rigorous testing to enhance scientific reliability in Li-CO(2) battery research so that this field can develop sustainably.