Mechanistic Understanding of the Solid Product in O₂‐Involved Li‐CO₂ Batteries

ABSTRACT Lithium carbonate, a solid discharge product, is closely associated with the discharge performance of oxygen‐involved lithium‐carbon dioxide batteries that exacerbates concentration polarization and electrode passivation. Although numerous strategies to enhance battery performance have progressed, the mechanistic understanding of lithium carbonate on oxygen‐involved lithium‐carbon dioxide batteries is still confusing. Herein, the effects of lithium carbonate over past decades are traced, including the lithium carbonate product morphology, reaction pathway, formation intermediate, and growth mechanism. The lithium carbonate nucleation and growth are crucial factors that influence battery performance. This perspective proposes a brand‐new growth mechanism coupling of solution and surface mechanisms based on experimental results and theories, which extends the growth space of the product and enhances the discharge capacity. Developing advanced technologies are expected to reveal complex lithium carbonate formation pathways and spearhead advanced oxygen‐involved lithium‐carbon dioxide batteries.