Revealing the CO2 Conversion at Electrode/Electrolyte Interfaces in Li–CO2 Batteries via Nanoscale Visualization Methods

• Published in: Angewandte Chemie International Edition 2024-01, Vol.63 (1), p.e202316781-n/a
• Main Authors: Shen, Zhen‐Zhen, Lang, Shuang‐Yan, Liu, Rui‐Zhi, Zhou, Chi, Zhang, Yao‐Zu, Liu, Bing, Wen, Rui
• Format: Article
• Language: English
• Subjects: Atomic force microscopy; Batteries; Carbon dioxide; Carbon sequestration; Chemical reactions; Confocal microscopy; Decomposition; Differential Interference Contrast Microscopy; Discharge; Electrochemical Atomic Force Microscopy; Electrochemistry; Electrode/Electrolyte Interfaces; Electrodes; Electrolytes; Energy storage; Flakes; Growth models; In Situ Visualization; Interface reactions; Interfaces; Intermediates; Irradiation; Lasers; Lithium; Lithium carbonate; Li–CO2 Batteries; Microscopy; Recharge; Three dimensional models
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.202316781

Lithium–carbon dioxide (Li–CO2) battery technology presents a promising opportunity for carbon capture and energy storage. Despite tremendous efforts in Li–CO2 batteries, the complex electrode/electrolyte/CO2 triple‐phase interfacial processes remain poorly understood, in particular at the nanoscale. Here, using in situ atomic force microscopy and laser confocal microscopy‐differential interference contrast microscopy, we directly observed the CO2 conversion processes in Li–CO2 batteries at the nanoscale, and further revealed a laser‐tuned reaction pathway based on the real‐time observations. During discharge, a bi‐component composite, Li2CO3/C, deposits as micron‐sized clusters through a 3D progressive growth model, followed by a 3D decomposition pathway during the subsequent recharge. When the cell operates under laser (λ=405 nm) irradiation, densely packed Li2CO3/C flakes deposit rapidly during discharge. Upon the recharge, they predominantly decompose at the interfaces of the flake and electrode, detaching themselves from the electrode and causing irreversible capacity degradation. In situ Raman shows that the laser promotes the formation of poorly soluble intermediates, Li2C2O4, which in turn affects growth/decomposition pathways of Li2CO3/C and the cell performance. Our findings provide mechanistic insights into interfacial evolution in Li–CO2 batteries and the laser‐tuned CO2 conversion reactions, which can inspire strategies of monitoring and controlling the multistep and multiphase interfacial reactions in advanced electrochemical devices. Using in situ atomic force microscopy, laser confocal microscopy‐differential interference contrast microscopy and Raman spectroscopy, we explored the electrode/electrolyte interfacial evolution in Li–CO2 batteries. The results indicate that the laser alters the reaction pathways of the CO2 reduction processes, which changes the morphological evolution of the discharge products at the interfaces, and in turn, affects the cell performance.